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    <title>DEV Community: Jhonathan dos reis</title>
    <description>The latest articles on DEV Community by Jhonathan dos reis (@jhonathandosreis).</description>
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      <title>Separation of Concerns em Java: O Jeito Simples</title>
      <dc:creator>Jhonathan dos reis</dc:creator>
      <pubDate>Mon, 15 Sep 2025 17:19:08 +0000</pubDate>
      <link>https://dev.to/jhonathandosreis/separation-of-concerns-em-java-o-jeito-simples-1c9b</link>
      <guid>https://dev.to/jhonathandosreis/separation-of-concerns-em-java-o-jeito-simples-1c9b</guid>
      <description>&lt;p&gt;É difícil aceitar a verdade. Que sua aplicação Java com mais de 2000 linhas está toda escrita em uma única classe... mas você já sabe disso, ou pelo menos espero que saiba. Eu sei que você já tentou torná-la mais compacta, mas as coisas simplesmente não estão fazendo sentido.&lt;/p&gt;

&lt;p&gt;É aqui que entra um princípio que transcende tempo e espaço, que nos ajuda em todos os aspectos da nossa vida: &lt;strong&gt;Separation of Concerns&lt;/strong&gt; (Separação de Responsabilidades) ou &lt;strong&gt;SoC&lt;/strong&gt;.&lt;/p&gt;

&lt;p&gt;Eu sei que pode parecer intimidante, mas não se preocupe - o Tio T está aqui e vou tornar tudo o mais simples possível para o seu prazer.&lt;/p&gt;

&lt;p&gt;Então hoje vamos passar por estes pontos:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;O que é Separation of Concerns?&lt;/li&gt;
&lt;li&gt;Coesão e Acoplamento
&lt;/li&gt;
&lt;li&gt;Por que funciona?&lt;/li&gt;
&lt;li&gt;Exemplos práticos em Java&lt;/li&gt;
&lt;li&gt;Conclusão&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;Antes de começarmos, fique confortável, pegue sua bebida favorita e coloque seus óculos inteligentes. Vamos começar!&lt;/p&gt;

&lt;h2&gt;
  
  
  O que é Separation of Concerns?
&lt;/h2&gt;

&lt;p&gt;Como todo bom post técnico precisa de uma citação, aqui está algo que copiei da Wikipedia:&lt;/p&gt;

&lt;blockquote&gt;
&lt;p&gt;&lt;em&gt;"Em ciência da computação, separation of concerns é um princípio de design para separar um programa de computador em seções distintas, de modo que cada seção aborde uma preocupação separada."&lt;/em&gt;&lt;/p&gt;
&lt;/blockquote&gt;

&lt;p&gt;Ok, agora que as formalidades acabaram, deixe-me explicar de forma simples.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Separation of Concerns é um princípio universal que praticamente todas as pessoas aplicam.&lt;/strong&gt; Não estou falando apenas de desenvolvimento de software - ele se aplica a muitos outros campos também.&lt;/p&gt;

&lt;h3&gt;
  
  
  Um Exemplo do Mundo Real
&lt;/h3&gt;

&lt;p&gt;Imagine sua cozinha. Você não guarda talheres no mesmo lugar que produtos de limpeza, certo? Você tem gavetas separadas para:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Talheres&lt;/li&gt;
&lt;li&gt;Panelas&lt;/li&gt;
&lt;li&gt;Temperos&lt;/li&gt;
&lt;li&gt;Produtos de limpeza&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;Por quê? Porque &lt;strong&gt;cada categoria tem uma responsabilidade diferente&lt;/strong&gt;, e misturá-las tornaria sua vida um caos.&lt;/p&gt;

&lt;h2&gt;
  
  
  Como SoC se Aplica ao Java?
&lt;/h2&gt;

&lt;p&gt;Em Java, aplicamos SoC em vários níveis:&lt;/p&gt;

&lt;h3&gt;
  
  
  1. Nível de Arquitetura - Padrão MVC
&lt;/h3&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight java"&gt;&lt;code&gt;&lt;span class="c1"&gt;// Model - Responsável pelos dados&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;Usuario&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;Long&lt;/span&gt; &lt;span class="n"&gt;id&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;String&lt;/span&gt; &lt;span class="n"&gt;nome&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;String&lt;/span&gt; &lt;span class="n"&gt;email&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;

    &lt;span class="c1"&gt;// getters e setters&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="c1"&gt;// View - Responsável pela apresentação (JSP exemplo)&lt;/span&gt;
&lt;span class="o"&gt;&amp;lt;%&lt;/span&gt;&lt;span class="err"&gt;@&lt;/span&gt; &lt;span class="n"&gt;page&lt;/span&gt; &lt;span class="n"&gt;contentType&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"text/html;charset=UTF-8"&lt;/span&gt; &lt;span class="o"&gt;%&amp;gt;&lt;/span&gt;
&lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="n"&gt;html&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt;
&lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="n"&gt;body&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt;
    &lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="n"&gt;h1&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt;&lt;span class="nc"&gt;Bem&lt;/span&gt;&lt;span class="o"&gt;-&lt;/span&gt;&lt;span class="n"&gt;vindo&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="err"&gt;$&lt;/span&gt;&lt;span class="o"&gt;{&lt;/span&gt;&lt;span class="n"&gt;usuario&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;nome&lt;/span&gt;&lt;span class="o"&gt;}!&amp;lt;/&lt;/span&gt;&lt;span class="n"&gt;h1&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt;
&lt;span class="o"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="n"&gt;body&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt;
&lt;span class="o"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="n"&gt;html&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt;

&lt;span class="c1"&gt;// Controller - Responsável pela lógica de controle&lt;/span&gt;
&lt;span class="nd"&gt;@RestController&lt;/span&gt;
&lt;span class="nd"&gt;@RequestMapping&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s"&gt;"/usuarios"&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;UsuarioController&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="nd"&gt;@Autowired&lt;/span&gt;
    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;UsuarioService&lt;/span&gt; &lt;span class="n"&gt;service&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;

    &lt;span class="nd"&gt;@GetMapping&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s"&gt;"/{id}"&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt;
    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="nc"&gt;Usuario&lt;/span&gt; &lt;span class="nf"&gt;buscarUsuario&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nd"&gt;@PathVariable&lt;/span&gt; &lt;span class="nc"&gt;Long&lt;/span&gt; &lt;span class="n"&gt;id&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;service&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;buscarPorId&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;id&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  2. Nível de Camadas - Arquitetura em Camadas
&lt;/h3&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight java"&gt;&lt;code&gt;&lt;span class="c1"&gt;// Camada de Apresentação&lt;/span&gt;
&lt;span class="nd"&gt;@RestController&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;PedidoController&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="nd"&gt;@Autowired&lt;/span&gt;
    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;PedidoService&lt;/span&gt; &lt;span class="n"&gt;pedidoService&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;

    &lt;span class="nd"&gt;@PostMapping&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s"&gt;"/pedidos"&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt;
    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="nc"&gt;ResponseEntity&lt;/span&gt;&lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;Pedido&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="nf"&gt;criarPedido&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nd"&gt;@RequestBody&lt;/span&gt; &lt;span class="nc"&gt;PedidoDTO&lt;/span&gt; &lt;span class="n"&gt;dto&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="nc"&gt;Pedido&lt;/span&gt; &lt;span class="n"&gt;pedido&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;pedidoService&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;processar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;dto&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nc"&gt;ResponseEntity&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;ok&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;pedido&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="c1"&gt;// Camada de Negócio&lt;/span&gt;
&lt;span class="nd"&gt;@Service&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;PedidoService&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="nd"&gt;@Autowired&lt;/span&gt;
    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;PedidoRepository&lt;/span&gt; &lt;span class="n"&gt;repository&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="nd"&gt;@Autowired&lt;/span&gt;
    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;EmailService&lt;/span&gt; &lt;span class="n"&gt;emailService&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;

    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="nc"&gt;Pedido&lt;/span&gt; &lt;span class="nf"&gt;processar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;PedidoDTO&lt;/span&gt; &lt;span class="n"&gt;dto&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="c1"&gt;// Lógica de negócio&lt;/span&gt;
        &lt;span class="nc"&gt;Pedido&lt;/span&gt; &lt;span class="n"&gt;pedido&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Pedido&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;dto&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="n"&gt;pedido&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;calcularTotal&lt;/span&gt;&lt;span class="o"&gt;();&lt;/span&gt;
        &lt;span class="n"&gt;pedido&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;repository&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;save&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;pedido&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="n"&gt;emailService&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;enviarConfirmacao&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;pedido&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;pedido&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="c1"&gt;// Camada de Dados&lt;/span&gt;
&lt;span class="nd"&gt;@Repository&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;interface&lt;/span&gt; &lt;span class="nc"&gt;PedidoRepository&lt;/span&gt; &lt;span class="kd"&gt;extends&lt;/span&gt; &lt;span class="nc"&gt;JpaRepository&lt;/span&gt;&lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;Pedido&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="nc"&gt;Long&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="nc"&gt;List&lt;/span&gt;&lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;Pedido&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="nf"&gt;findByClienteId&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;Long&lt;/span&gt; &lt;span class="n"&gt;clienteId&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Coesão e Acoplamento
&lt;/h2&gt;

&lt;p&gt;Dois conceitos fundamentais em SoC:&lt;/p&gt;

&lt;h3&gt;
  
  
  Alta Coesão (BOM ✅)
&lt;/h3&gt;

&lt;p&gt;Elementos relacionados ficam juntos.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight java"&gt;&lt;code&gt;&lt;span class="c1"&gt;// ALTA COESÃO - Todos os métodos são sobre gerenciamento de conta&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;ContaBancaria&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="n"&gt;saldo&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;String&lt;/span&gt; &lt;span class="n"&gt;numero&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;

    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;depositar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="n"&gt;valor&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;saldo&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;saldo&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;add&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;valor&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;

    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;sacar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="n"&gt;valor&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;saldo&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;compareTo&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;valor&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;&amp;gt;=&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
            &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;saldo&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;saldo&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;subtract&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;valor&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="o"&gt;}&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;

    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="nf"&gt;consultarSaldo&lt;/span&gt;&lt;span class="o"&gt;()&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;saldo&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  Baixo Acoplamento (BOM ✅)
&lt;/h3&gt;

&lt;p&gt;Módulos dependem minimamente uns dos outros.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight java"&gt;&lt;code&gt;&lt;span class="c1"&gt;// BAIXO ACOPLAMENTO - Usando interfaces&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;interface&lt;/span&gt; &lt;span class="nc"&gt;NotificadorService&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;enviar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;String&lt;/span&gt; &lt;span class="n"&gt;mensagem&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="nc"&gt;String&lt;/span&gt; &lt;span class="n"&gt;destinatario&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="nd"&gt;@Service&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;EmailNotificador&lt;/span&gt; &lt;span class="kd"&gt;implements&lt;/span&gt; &lt;span class="nc"&gt;NotificadorService&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;enviar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;String&lt;/span&gt; &lt;span class="n"&gt;mensagem&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="nc"&gt;String&lt;/span&gt; &lt;span class="n"&gt;destinatario&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="c1"&gt;// Implementação de email&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="nd"&gt;@Service&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;SMSNotificador&lt;/span&gt; &lt;span class="kd"&gt;implements&lt;/span&gt; &lt;span class="nc"&gt;NotificadorService&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;enviar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;String&lt;/span&gt; &lt;span class="n"&gt;mensagem&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="nc"&gt;String&lt;/span&gt; &lt;span class="n"&gt;destinatario&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="c1"&gt;// Implementação de SMS&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="c1"&gt;// A classe não está acoplada a uma implementação específica&lt;/span&gt;
&lt;span class="nd"&gt;@Service&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;PedidoService&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="nd"&gt;@Autowired&lt;/span&gt;
    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;NotificadorService&lt;/span&gt; &lt;span class="n"&gt;notificador&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt; &lt;span class="c1"&gt;// Interface, não implementação!&lt;/span&gt;

    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;finalizarPedido&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;Pedido&lt;/span&gt; &lt;span class="n"&gt;pedido&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="c1"&gt;// processar pedido...&lt;/span&gt;
        &lt;span class="n"&gt;notificador&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;enviar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s"&gt;"Pedido confirmado!"&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="n"&gt;pedido&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;getCliente&lt;/span&gt;&lt;span class="o"&gt;().&lt;/span&gt;&lt;span class="na"&gt;getEmail&lt;/span&gt;&lt;span class="o"&gt;());&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Por Que SoC Funciona?
&lt;/h2&gt;

&lt;h3&gt;
  
  
  1. Manutenibilidade 🔧
&lt;/h3&gt;

&lt;p&gt;Quando você precisa fazer uma mudança, você sabe exatamente onde ir:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight java"&gt;&lt;code&gt;&lt;span class="c1"&gt;// Antes de SoC - Tudo misturado 😱&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;SistemaPedido&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;processarPedido&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;String&lt;/span&gt; &lt;span class="n"&gt;item&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="kt"&gt;int&lt;/span&gt; &lt;span class="n"&gt;quantidade&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="nc"&gt;String&lt;/span&gt; &lt;span class="n"&gt;email&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="c1"&gt;// Validação&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;item&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="kc"&gt;null&lt;/span&gt; &lt;span class="o"&gt;||&lt;/span&gt; &lt;span class="n"&gt;quantidade&lt;/span&gt; &lt;span class="o"&gt;&amp;lt;=&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
            &lt;span class="k"&gt;throw&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nf"&gt;IllegalArgumentException&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s"&gt;"Dados inválidos"&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="o"&gt;}&lt;/span&gt;

        &lt;span class="c1"&gt;// Cálculo de preço&lt;/span&gt;
        &lt;span class="kt"&gt;double&lt;/span&gt; &lt;span class="n"&gt;preco&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;quantidade&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="mf"&gt;10.0&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;quantidade&lt;/span&gt; &lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="mi"&gt;100&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
            &lt;span class="n"&gt;preco&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;preco&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="mf"&gt;0.9&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt; &lt;span class="c1"&gt;// desconto&lt;/span&gt;
        &lt;span class="o"&gt;}&lt;/span&gt;

        &lt;span class="c1"&gt;// Salvar no banco&lt;/span&gt;
        &lt;span class="nc"&gt;Connection&lt;/span&gt; &lt;span class="n"&gt;conn&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nc"&gt;DriverManager&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;getConnection&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s"&gt;"jdbc:..."&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="nc"&gt;PreparedStatement&lt;/span&gt; &lt;span class="n"&gt;stmt&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;conn&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;prepareStatement&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s"&gt;"INSERT INTO pedidos..."&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="c1"&gt;// ...&lt;/span&gt;

        &lt;span class="c1"&gt;// Enviar email&lt;/span&gt;
        &lt;span class="nc"&gt;Properties&lt;/span&gt; &lt;span class="n"&gt;props&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Properties&lt;/span&gt;&lt;span class="o"&gt;();&lt;/span&gt;
        &lt;span class="nc"&gt;Session&lt;/span&gt; &lt;span class="n"&gt;session&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nc"&gt;Session&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;getInstance&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;props&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="nc"&gt;MimeMessage&lt;/span&gt; &lt;span class="n"&gt;message&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;MimeMessage&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;session&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="c1"&gt;// ...&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="c1"&gt;// Depois de SoC - Tudo organizado 😊&lt;/span&gt;
&lt;span class="nd"&gt;@Service&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;PedidoService&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="nd"&gt;@Autowired&lt;/span&gt; &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;ValidadorPedido&lt;/span&gt; &lt;span class="n"&gt;validador&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="nd"&gt;@Autowired&lt;/span&gt; &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;CalculadoraPreco&lt;/span&gt; &lt;span class="n"&gt;calculadora&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="nd"&gt;@Autowired&lt;/span&gt; &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;PedidoRepository&lt;/span&gt; &lt;span class="n"&gt;repository&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="nd"&gt;@Autowired&lt;/span&gt; &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;EmailService&lt;/span&gt; &lt;span class="n"&gt;emailService&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;

    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;processarPedido&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;PedidoDTO&lt;/span&gt; &lt;span class="n"&gt;dto&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="n"&gt;validador&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;validar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;dto&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="n"&gt;preco&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;calculadora&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;calcular&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;dto&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="nc"&gt;Pedido&lt;/span&gt; &lt;span class="n"&gt;pedido&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Pedido&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;dto&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="n"&gt;preco&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="n"&gt;repository&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;save&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;pedido&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="n"&gt;emailService&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;enviarConfirmacao&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;pedido&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  2. Testabilidade 🧪
&lt;/h3&gt;

&lt;p&gt;Com SoC, testar fica muito mais fácil:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight java"&gt;&lt;code&gt;&lt;span class="nd"&gt;@Test&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;testCalculadoraPreco&lt;/span&gt;&lt;span class="o"&gt;()&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="nc"&gt;CalculadoraPreco&lt;/span&gt; &lt;span class="n"&gt;calc&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;CalculadoraPreco&lt;/span&gt;&lt;span class="o"&gt;();&lt;/span&gt;
    &lt;span class="nc"&gt;PedidoDTO&lt;/span&gt; &lt;span class="n"&gt;dto&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;PedidoDTO&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s"&gt;"Item"&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;150&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;

    &lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="n"&gt;preco&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;calc&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;calcular&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;dto&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;

    &lt;span class="c1"&gt;// Testando apenas a lógica de cálculo, isoladamente!&lt;/span&gt;
    &lt;span class="n"&gt;assertEquals&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;BigDecimal&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s"&gt;"1350.00"&lt;/span&gt;&lt;span class="o"&gt;),&lt;/span&gt; &lt;span class="n"&gt;preco&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt; &lt;span class="c1"&gt;// 150 * 10 * 0.9&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="nd"&gt;@Test&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;testPedidoService&lt;/span&gt;&lt;span class="o"&gt;()&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="c1"&gt;// Usando mocks para isolar o teste&lt;/span&gt;
    &lt;span class="nc"&gt;ValidadorPedido&lt;/span&gt; &lt;span class="n"&gt;validador&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;mock&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;ValidadorPedido&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;class&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
    &lt;span class="nc"&gt;CalculadoraPreco&lt;/span&gt; &lt;span class="n"&gt;calculadora&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;mock&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;CalculadoraPreco&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;class&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
    &lt;span class="nc"&gt;PedidoRepository&lt;/span&gt; &lt;span class="n"&gt;repository&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;mock&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;PedidoRepository&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;class&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
    &lt;span class="nc"&gt;EmailService&lt;/span&gt; &lt;span class="n"&gt;emailService&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;mock&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;EmailService&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;class&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;

    &lt;span class="n"&gt;when&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;calculadora&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;calcular&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;any&lt;/span&gt;&lt;span class="o"&gt;())).&lt;/span&gt;&lt;span class="na"&gt;thenReturn&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;BigDecimal&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s"&gt;"100"&lt;/span&gt;&lt;span class="o"&gt;));&lt;/span&gt;

    &lt;span class="nc"&gt;PedidoService&lt;/span&gt; &lt;span class="n"&gt;service&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;PedidoService&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;validador&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="n"&gt;calculadora&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="n"&gt;repository&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="n"&gt;emailService&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
    &lt;span class="n"&gt;service&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;processarPedido&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;PedidoDTO&lt;/span&gt;&lt;span class="o"&gt;());&lt;/span&gt;

    &lt;span class="n"&gt;verify&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;repository&lt;/span&gt;&lt;span class="o"&gt;).&lt;/span&gt;&lt;span class="na"&gt;save&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;any&lt;/span&gt;&lt;span class="o"&gt;());&lt;/span&gt;
    &lt;span class="n"&gt;verify&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;emailService&lt;/span&gt;&lt;span class="o"&gt;).&lt;/span&gt;&lt;span class="na"&gt;enviarConfirmacao&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;any&lt;/span&gt;&lt;span class="o"&gt;());&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  3. Reutilização ♻️
&lt;/h3&gt;

&lt;p&gt;Componentes bem separados podem ser reutilizados:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight java"&gt;&lt;code&gt;&lt;span class="c1"&gt;// Este serviço de email pode ser usado em qualquer lugar!&lt;/span&gt;
&lt;span class="nd"&gt;@Service&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;EmailService&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;enviar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;Email&lt;/span&gt; &lt;span class="n"&gt;email&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="c1"&gt;// implementação&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="c1"&gt;// Usado no PedidoService&lt;/span&gt;
&lt;span class="nd"&gt;@Service&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;PedidoService&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="nd"&gt;@Autowired&lt;/span&gt; &lt;span class="nc"&gt;EmailService&lt;/span&gt; &lt;span class="n"&gt;emailService&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="c1"&gt;// ...&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="c1"&gt;// Usado no UsuarioService também!&lt;/span&gt;
&lt;span class="nd"&gt;@Service&lt;/span&gt; 
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;UsuarioService&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="nd"&gt;@Autowired&lt;/span&gt; &lt;span class="nc"&gt;EmailService&lt;/span&gt; &lt;span class="n"&gt;emailService&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="c1"&gt;// ...&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Exemplos Práticos do Mundo Java
&lt;/h2&gt;

&lt;h3&gt;
  
  
  Exemplo 1: Sistema de E-commerce
&lt;/h3&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight java"&gt;&lt;code&gt;&lt;span class="c1"&gt;// ❌ RUIM - Violando SoC&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;Produto&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;String&lt;/span&gt; &lt;span class="n"&gt;nome&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="n"&gt;preco&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;

    &lt;span class="c1"&gt;// Métodos de negócio - OK&lt;/span&gt;
    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="nf"&gt;calcularPrecoComDesconto&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="n"&gt;percentual&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;preco&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;multiply&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;BigDecimal&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;ONE&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;subtract&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;percentual&lt;/span&gt;&lt;span class="o"&gt;));&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;

    &lt;span class="c1"&gt;// Método de persistência - NÃO DEVERIA ESTAR AQUI!&lt;/span&gt;
    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;salvarNoBanco&lt;/span&gt;&lt;span class="o"&gt;()&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="nc"&gt;Connection&lt;/span&gt; &lt;span class="n"&gt;conn&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nc"&gt;DriverManager&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;getConnection&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s"&gt;"..."&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="c1"&gt;// código SQL...&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;

    &lt;span class="c1"&gt;// Método de apresentação - NÃO DEVERIA ESTAR AQUI!&lt;/span&gt;
    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="nc"&gt;String&lt;/span&gt; &lt;span class="nf"&gt;toHTML&lt;/span&gt;&lt;span class="o"&gt;()&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="s"&gt;"&amp;lt;div&amp;gt;"&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="n"&gt;nome&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="s"&gt;" - R$ "&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="n"&gt;preco&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="s"&gt;"&amp;lt;/div&amp;gt;"&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="c1"&gt;// ✅ BOM - Respeitando SoC&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;Produto&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;String&lt;/span&gt; &lt;span class="n"&gt;nome&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="n"&gt;preco&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;

    &lt;span class="c1"&gt;// Apenas lógica de negócio&lt;/span&gt;
    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="nf"&gt;calcularPrecoComDesconto&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="n"&gt;percentual&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;preco&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;multiply&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;BigDecimal&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;ONE&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;subtract&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;percentual&lt;/span&gt;&lt;span class="o"&gt;));&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="nd"&gt;@Repository&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;ProdutoRepository&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;salvar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;Produto&lt;/span&gt; &lt;span class="n"&gt;produto&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="c1"&gt;// código de persistência&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="nd"&gt;@Component&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;ProdutoView&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="nc"&gt;String&lt;/span&gt; &lt;span class="nf"&gt;renderizar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;Produto&lt;/span&gt; &lt;span class="n"&gt;produto&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="s"&gt;"&amp;lt;div&amp;gt;"&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="n"&gt;produto&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;getNome&lt;/span&gt;&lt;span class="o"&gt;()&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="s"&gt;" - R$ "&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="n"&gt;produto&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;getPreco&lt;/span&gt;&lt;span class="o"&gt;()&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="s"&gt;"&amp;lt;/div&amp;gt;"&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  Exemplo 2: Processamento de Pagamento
&lt;/h3&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight java"&gt;&lt;code&gt;&lt;span class="c1"&gt;// Separando responsabilidades em um sistema de pagamento&lt;/span&gt;

&lt;span class="c1"&gt;// 1. Validação&lt;/span&gt;
&lt;span class="nd"&gt;@Component&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;ValidadorPagamento&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;validar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;DadosPagamento&lt;/span&gt; &lt;span class="n"&gt;dados&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;dados&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;getValor&lt;/span&gt;&lt;span class="o"&gt;().&lt;/span&gt;&lt;span class="na"&gt;compareTo&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;BigDecimal&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;ZERO&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;&amp;lt;=&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
            &lt;span class="k"&gt;throw&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nf"&gt;ValorInvalidoException&lt;/span&gt;&lt;span class="o"&gt;();&lt;/span&gt;
        &lt;span class="o"&gt;}&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="o"&gt;(!&lt;/span&gt;&lt;span class="n"&gt;isCartaoValido&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;dados&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;getNumeroCartao&lt;/span&gt;&lt;span class="o"&gt;()))&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
            &lt;span class="k"&gt;throw&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nf"&gt;CartaoInvalidoException&lt;/span&gt;&lt;span class="o"&gt;();&lt;/span&gt;
        &lt;span class="o"&gt;}&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;

    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="kt"&gt;boolean&lt;/span&gt; &lt;span class="nf"&gt;isCartaoValido&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;String&lt;/span&gt; &lt;span class="n"&gt;numero&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="c1"&gt;// Algoritmo de Luhn&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt; &lt;span class="c1"&gt;// simplificado&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="c1"&gt;// 2. Processamento&lt;/span&gt;
&lt;span class="nd"&gt;@Component&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;ProcessadorPagamento&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="nd"&gt;@Autowired&lt;/span&gt;
    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;GatewayPagamento&lt;/span&gt; &lt;span class="n"&gt;gateway&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;

    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="nc"&gt;RespostaPagamento&lt;/span&gt; &lt;span class="nf"&gt;processar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;DadosPagamento&lt;/span&gt; &lt;span class="n"&gt;dados&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;gateway&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;cobrar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;dados&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="c1"&gt;// 3. Notificação&lt;/span&gt;
&lt;span class="nd"&gt;@Component&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;NotificadorPagamento&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="nd"&gt;@Autowired&lt;/span&gt;
    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;EmailService&lt;/span&gt; &lt;span class="n"&gt;emailService&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="nd"&gt;@Autowired&lt;/span&gt;
    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;SMSService&lt;/span&gt; &lt;span class="n"&gt;smsService&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;

    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;notificarSucesso&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;Pagamento&lt;/span&gt; &lt;span class="n"&gt;pagamento&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="n"&gt;emailService&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;enviar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;criarEmailSucesso&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;pagamento&lt;/span&gt;&lt;span class="o"&gt;));&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;pagamento&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;getCliente&lt;/span&gt;&lt;span class="o"&gt;().&lt;/span&gt;&lt;span class="na"&gt;temCelular&lt;/span&gt;&lt;span class="o"&gt;())&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
            &lt;span class="n"&gt;smsService&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;enviar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;criarSMSSucesso&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;pagamento&lt;/span&gt;&lt;span class="o"&gt;));&lt;/span&gt;
        &lt;span class="o"&gt;}&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="c1"&gt;// 4. Orquestração&lt;/span&gt;
&lt;span class="nd"&gt;@Service&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;PagamentoService&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="nd"&gt;@Autowired&lt;/span&gt; &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;ValidadorPagamento&lt;/span&gt; &lt;span class="n"&gt;validador&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="nd"&gt;@Autowired&lt;/span&gt; &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;ProcessadorPagamento&lt;/span&gt; &lt;span class="n"&gt;processador&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="nd"&gt;@Autowired&lt;/span&gt; &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;NotificadorPagamento&lt;/span&gt; &lt;span class="n"&gt;notificador&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="nd"&gt;@Autowired&lt;/span&gt; &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;PagamentoRepository&lt;/span&gt; &lt;span class="n"&gt;repository&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;

    &lt;span class="nd"&gt;@Transactional&lt;/span&gt;
    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="nc"&gt;Pagamento&lt;/span&gt; &lt;span class="nf"&gt;realizarPagamento&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;DadosPagamento&lt;/span&gt; &lt;span class="n"&gt;dados&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="c1"&gt;// Cada componente faz sua parte&lt;/span&gt;
        &lt;span class="n"&gt;validador&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;validar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;dados&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="nc"&gt;RespostaPagamento&lt;/span&gt; &lt;span class="n"&gt;resposta&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;processador&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;processar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;dados&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="nc"&gt;Pagamento&lt;/span&gt; &lt;span class="n"&gt;pagamento&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Pagamento&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;dados&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="n"&gt;resposta&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="n"&gt;repository&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;save&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;pagamento&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="n"&gt;notificador&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;notificarSucesso&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;pagamento&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;pagamento&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  SoC em Diferentes Níveis
&lt;/h2&gt;

&lt;h3&gt;
  
  
  Nível de Método
&lt;/h3&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight java"&gt;&lt;code&gt;&lt;span class="c1"&gt;// ❌ RUIM - Método fazendo muitas coisas&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;processarRelatorio&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;List&lt;/span&gt;&lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;Venda&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;vendas&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="c1"&gt;// Filtrar vendas&lt;/span&gt;
    &lt;span class="nc"&gt;List&lt;/span&gt;&lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;Venda&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;vendasValidas&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;ArrayList&lt;/span&gt;&lt;span class="o"&gt;&amp;lt;&amp;gt;();&lt;/span&gt;
    &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;Venda&lt;/span&gt; &lt;span class="n"&gt;v&lt;/span&gt; &lt;span class="o"&gt;:&lt;/span&gt; &lt;span class="n"&gt;vendas&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;v&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;getValor&lt;/span&gt;&lt;span class="o"&gt;()&lt;/span&gt; &lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt; &lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; &lt;span class="n"&gt;v&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;getData&lt;/span&gt;&lt;span class="o"&gt;()&lt;/span&gt; &lt;span class="o"&gt;!=&lt;/span&gt; &lt;span class="kc"&gt;null&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
            &lt;span class="n"&gt;vendasValidas&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;add&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;v&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="o"&gt;}&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;

    &lt;span class="c1"&gt;// Calcular total&lt;/span&gt;
    &lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="n"&gt;total&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nc"&gt;BigDecimal&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;ZERO&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;Venda&lt;/span&gt; &lt;span class="n"&gt;v&lt;/span&gt; &lt;span class="o"&gt;:&lt;/span&gt; &lt;span class="n"&gt;vendasValidas&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="n"&gt;total&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;total&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;add&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;v&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;getValor&lt;/span&gt;&lt;span class="o"&gt;());&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;

    &lt;span class="c1"&gt;// Formatar relatório&lt;/span&gt;
    &lt;span class="nc"&gt;StringBuilder&lt;/span&gt; &lt;span class="n"&gt;sb&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;StringBuilder&lt;/span&gt;&lt;span class="o"&gt;();&lt;/span&gt;
    &lt;span class="n"&gt;sb&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;append&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s"&gt;"Relatório de Vendas\n"&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
    &lt;span class="n"&gt;sb&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;append&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s"&gt;"Total: "&lt;/span&gt;&lt;span class="o"&gt;).&lt;/span&gt;&lt;span class="na"&gt;append&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;total&lt;/span&gt;&lt;span class="o"&gt;).&lt;/span&gt;&lt;span class="na"&gt;append&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s"&gt;"\n"&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;

    &lt;span class="c1"&gt;// Salvar arquivo&lt;/span&gt;
    &lt;span class="nc"&gt;Files&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;write&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;Paths&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;get&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s"&gt;"relatorio.txt"&lt;/span&gt;&lt;span class="o"&gt;),&lt;/span&gt; &lt;span class="n"&gt;sb&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;toString&lt;/span&gt;&lt;span class="o"&gt;().&lt;/span&gt;&lt;span class="na"&gt;getBytes&lt;/span&gt;&lt;span class="o"&gt;());&lt;/span&gt;

    &lt;span class="c1"&gt;// Enviar email&lt;/span&gt;
    &lt;span class="n"&gt;emailService&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;enviar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s"&gt;"relatorio@empresa.com"&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="n"&gt;sb&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;toString&lt;/span&gt;&lt;span class="o"&gt;());&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="c1"&gt;// ✅ BOM - Cada método com uma responsabilidade&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;processarRelatorio&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;List&lt;/span&gt;&lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;Venda&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;vendas&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="nc"&gt;List&lt;/span&gt;&lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;Venda&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;vendasValidas&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;filtrarVendasValidas&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;vendas&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
    &lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="n"&gt;total&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;calcularTotal&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;vendasValidas&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
    &lt;span class="nc"&gt;String&lt;/span&gt; &lt;span class="n"&gt;relatorio&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;formatarRelatorio&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;vendasValidas&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="n"&gt;total&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
    &lt;span class="n"&gt;salvarRelatorio&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;relatorio&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
    &lt;span class="n"&gt;enviarRelatorioPorEmail&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;relatorio&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;List&lt;/span&gt;&lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;Venda&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="nf"&gt;filtrarVendasValidas&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;List&lt;/span&gt;&lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;Venda&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;vendas&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;vendas&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;stream&lt;/span&gt;&lt;span class="o"&gt;()&lt;/span&gt;
        &lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;filter&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;v&lt;/span&gt; &lt;span class="o"&gt;-&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;v&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;getValor&lt;/span&gt;&lt;span class="o"&gt;().&lt;/span&gt;&lt;span class="na"&gt;compareTo&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;BigDecimal&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;ZERO&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt;
        &lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;filter&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;v&lt;/span&gt; &lt;span class="o"&gt;-&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;v&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;getData&lt;/span&gt;&lt;span class="o"&gt;()&lt;/span&gt; &lt;span class="o"&gt;!=&lt;/span&gt; &lt;span class="kc"&gt;null&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt;
        &lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;collect&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;Collectors&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;toList&lt;/span&gt;&lt;span class="o"&gt;());&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="nf"&gt;calcularTotal&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;List&lt;/span&gt;&lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;Venda&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;vendas&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;vendas&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;stream&lt;/span&gt;&lt;span class="o"&gt;()&lt;/span&gt;
        &lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;map&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nl"&gt;Venda:&lt;/span&gt;&lt;span class="o"&gt;:&lt;/span&gt;&lt;span class="n"&gt;getValor&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt;
        &lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;reduce&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;BigDecimal&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;ZERO&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="nl"&gt;BigDecimal:&lt;/span&gt;&lt;span class="o"&gt;:&lt;/span&gt;&lt;span class="n"&gt;add&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;String&lt;/span&gt; &lt;span class="nf"&gt;formatarRelatorio&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;List&lt;/span&gt;&lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;Venda&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;vendas&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="n"&gt;total&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nc"&gt;String&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;format&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s"&gt;"Relatório de Vendas\nTotal: %s\nQuantidade: %d"&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; 
                        &lt;span class="n"&gt;total&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="n"&gt;vendas&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;size&lt;/span&gt;&lt;span class="o"&gt;());&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  Nível de Pacotes
&lt;/h3&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;com.empresa.app/
├── controller/      # Responsável por receber requisições
│   ├── UsuarioController.java
│   └── ProdutoController.java
├── service/         # Lógica de negócio
│   ├── UsuarioService.java
│   └── ProdutoService.java
├── repository/      # Acesso a dados
│   ├── UsuarioRepository.java
│   └── ProdutoRepository.java
├── model/          # Entidades do domínio
│   ├── Usuario.java
│   └── Produto.java
├── dto/            # Objetos de transferência
│   ├── UsuarioDTO.java
│   └── ProdutoDTO.java
└── util/           # Utilitários
    ├── EmailUtil.java
    └── ValidadorUtil.java
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Aplicando SoC com Spring Boot
&lt;/h2&gt;

&lt;p&gt;Spring Boot naturalmente encoraja SoC através de suas anotações:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight java"&gt;&lt;code&gt;&lt;span class="nd"&gt;@Configuration&lt;/span&gt;  &lt;span class="c1"&gt;// Configuração separada&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;AppConfig&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="nd"&gt;@Bean&lt;/span&gt;
    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="nc"&gt;RestTemplate&lt;/span&gt; &lt;span class="nf"&gt;restTemplate&lt;/span&gt;&lt;span class="o"&gt;()&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nf"&gt;RestTemplate&lt;/span&gt;&lt;span class="o"&gt;();&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="nd"&gt;@Component&lt;/span&gt;      &lt;span class="c1"&gt;// Componente reutilizável&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;CacheManager&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;Map&lt;/span&gt;&lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;String&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="nc"&gt;Object&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;cache&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;HashMap&lt;/span&gt;&lt;span class="o"&gt;&amp;lt;&amp;gt;();&lt;/span&gt;
    &lt;span class="c1"&gt;// ...&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="nd"&gt;@Service&lt;/span&gt;        &lt;span class="c1"&gt;// Lógica de negócio&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;ClienteService&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="c1"&gt;// ...&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="nd"&gt;@Repository&lt;/span&gt;     &lt;span class="c1"&gt;// Acesso a dados&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;interface&lt;/span&gt; &lt;span class="nc"&gt;ClienteRepository&lt;/span&gt; &lt;span class="kd"&gt;extends&lt;/span&gt; &lt;span class="nc"&gt;JpaRepository&lt;/span&gt;&lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;Cliente&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="nc"&gt;Long&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="c1"&gt;// ...&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="nd"&gt;@RestController&lt;/span&gt; &lt;span class="c1"&gt;// Controlador REST&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;ClienteController&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="c1"&gt;// ...&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="nd"&gt;@Aspect&lt;/span&gt;         &lt;span class="c1"&gt;// Aspectos transversais (logging, segurança)&lt;/span&gt;
&lt;span class="nd"&gt;@Component&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;LoggingAspect&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="nd"&gt;@Around&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s"&gt;"@annotation(Loggable)"&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt;
    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="nc"&gt;Object&lt;/span&gt; &lt;span class="nf"&gt;logExecutionTime&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;ProceedingJoinPoint&lt;/span&gt; &lt;span class="n"&gt;joinPoint&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="kd"&gt;throws&lt;/span&gt; &lt;span class="nc"&gt;Throwable&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="kt"&gt;long&lt;/span&gt; &lt;span class="n"&gt;start&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nc"&gt;System&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;currentTimeMillis&lt;/span&gt;&lt;span class="o"&gt;();&lt;/span&gt;
        &lt;span class="nc"&gt;Object&lt;/span&gt; &lt;span class="n"&gt;proceed&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;joinPoint&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;proceed&lt;/span&gt;&lt;span class="o"&gt;();&lt;/span&gt;
        &lt;span class="kt"&gt;long&lt;/span&gt; &lt;span class="n"&gt;executionTime&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nc"&gt;System&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;currentTimeMillis&lt;/span&gt;&lt;span class="o"&gt;()&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt; &lt;span class="n"&gt;start&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
        &lt;span class="n"&gt;logger&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;info&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s"&gt;"{} executed in {} ms"&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="n"&gt;joinPoint&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;getSignature&lt;/span&gt;&lt;span class="o"&gt;(),&lt;/span&gt; &lt;span class="n"&gt;executionTime&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;proceed&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Padrões de Design que Implementam SoC
&lt;/h2&gt;

&lt;h3&gt;
  
  
  1. Strategy Pattern
&lt;/h3&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight java"&gt;&lt;code&gt;&lt;span class="c1"&gt;// Separando algoritmos de cálculo de frete&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;interface&lt;/span&gt; &lt;span class="nc"&gt;CalculadoraFrete&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="nf"&gt;calcular&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;Pedido&lt;/span&gt; &lt;span class="n"&gt;pedido&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="nd"&gt;@Component&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;FretePAC&lt;/span&gt; &lt;span class="kd"&gt;implements&lt;/span&gt; &lt;span class="nc"&gt;CalculadoraFrete&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="nf"&gt;calcular&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;Pedido&lt;/span&gt; &lt;span class="n"&gt;pedido&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;pedido&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;getPeso&lt;/span&gt;&lt;span class="o"&gt;().&lt;/span&gt;&lt;span class="na"&gt;multiply&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;BigDecimal&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s"&gt;"5.00"&lt;/span&gt;&lt;span class="o"&gt;));&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="nd"&gt;@Component&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;FreteSedex&lt;/span&gt; &lt;span class="kd"&gt;implements&lt;/span&gt; &lt;span class="nc"&gt;CalculadoraFrete&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="nf"&gt;calcular&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;Pedido&lt;/span&gt; &lt;span class="n"&gt;pedido&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;pedido&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;getPeso&lt;/span&gt;&lt;span class="o"&gt;().&lt;/span&gt;&lt;span class="na"&gt;multiply&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;BigDecimal&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s"&gt;"15.00"&lt;/span&gt;&lt;span class="o"&gt;));&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="nd"&gt;@Service&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;FreteService&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;Map&lt;/span&gt;&lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;TipoFrete&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="nc"&gt;CalculadoraFrete&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;calculadoras&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;

    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="nf"&gt;calcularFrete&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;Pedido&lt;/span&gt; &lt;span class="n"&gt;pedido&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="nc"&gt;TipoFrete&lt;/span&gt; &lt;span class="n"&gt;tipo&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;calculadoras&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;get&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;tipo&lt;/span&gt;&lt;span class="o"&gt;).&lt;/span&gt;&lt;span class="na"&gt;calcular&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;pedido&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  2. Observer Pattern
&lt;/h3&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight java"&gt;&lt;code&gt;&lt;span class="c1"&gt;// Separando notificações de eventos&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;interface&lt;/span&gt; &lt;span class="nc"&gt;EventListener&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;onPedidoCriado&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;Pedido&lt;/span&gt; &lt;span class="n"&gt;pedido&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="nd"&gt;@Component&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;EmailListener&lt;/span&gt; &lt;span class="kd"&gt;implements&lt;/span&gt; &lt;span class="nc"&gt;EventListener&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;onPedidoCriado&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;Pedido&lt;/span&gt; &lt;span class="n"&gt;pedido&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="c1"&gt;// Enviar email&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="nd"&gt;@Component&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;EstoqueListener&lt;/span&gt; &lt;span class="kd"&gt;implements&lt;/span&gt; &lt;span class="nc"&gt;EventListener&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;onPedidoCriado&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;Pedido&lt;/span&gt; &lt;span class="n"&gt;pedido&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="c1"&gt;// Atualizar estoque&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="nd"&gt;@Component&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;NotaFiscalListener&lt;/span&gt; &lt;span class="kd"&gt;implements&lt;/span&gt; &lt;span class="nc"&gt;EventListener&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;onPedidoCriado&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;Pedido&lt;/span&gt; &lt;span class="n"&gt;pedido&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="c1"&gt;// Gerar nota fiscal&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="nd"&gt;@Service&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;PedidoService&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="nd"&gt;@Autowired&lt;/span&gt;
    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;List&lt;/span&gt;&lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;EventListener&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;listeners&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;

    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;criarPedido&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;PedidoDTO&lt;/span&gt; &lt;span class="n"&gt;dto&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="nc"&gt;Pedido&lt;/span&gt; &lt;span class="n"&gt;pedido&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Pedido&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;dto&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
        &lt;span class="c1"&gt;// salvar pedido...&lt;/span&gt;

        &lt;span class="c1"&gt;// Notificar todos os interessados&lt;/span&gt;
        &lt;span class="n"&gt;listeners&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;forEach&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;l&lt;/span&gt; &lt;span class="o"&gt;-&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;l&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;onPedidoCriado&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;pedido&lt;/span&gt;&lt;span class="o"&gt;));&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Microserviços: SoC em Escala
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight java"&gt;&lt;code&gt;&lt;span class="c1"&gt;// Serviço de Usuários&lt;/span&gt;
&lt;span class="nd"&gt;@SpringBootApplication&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;UserServiceApplication&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="c1"&gt;// Responsável apenas por usuários&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="c1"&gt;// Serviço de Pedidos&lt;/span&gt;
&lt;span class="nd"&gt;@SpringBootApplication&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;OrderServiceApplication&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="c1"&gt;// Responsável apenas por pedidos&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="c1"&gt;// Serviço de Notificações&lt;/span&gt;
&lt;span class="nd"&gt;@SpringBootApplication&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;NotificationServiceApplication&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="c1"&gt;// Responsável apenas por notificações&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="c1"&gt;// Comunicação via REST ou mensageria&lt;/span&gt;
&lt;span class="nd"&gt;@FeignClient&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;name&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="s"&gt;"user-service"&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;interface&lt;/span&gt; &lt;span class="nc"&gt;UserServiceClient&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="nd"&gt;@GetMapping&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s"&gt;"/users/{id}"&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt;
    &lt;span class="nc"&gt;User&lt;/span&gt; &lt;span class="nf"&gt;getUser&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nd"&gt;@PathVariable&lt;/span&gt; &lt;span class="nc"&gt;Long&lt;/span&gt; &lt;span class="n"&gt;id&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Armadilhas Comuns e Como Evitá-las
&lt;/h2&gt;

&lt;h3&gt;
  
  
  1. God Class (Classe Deus)
&lt;/h3&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight java"&gt;&lt;code&gt;&lt;span class="c1"&gt;// ❌ RUIM - Classe fazendo tudo&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;SistemaCompleto&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="c1"&gt;// 50 atributos&lt;/span&gt;
    &lt;span class="c1"&gt;// 100 métodos&lt;/span&gt;
    &lt;span class="c1"&gt;// Validação, cálculo, persistência, apresentação...&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="c1"&gt;// ✅ BOM - Responsabilidades distribuídas&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;Usuario&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt; &lt;span class="cm"&gt;/* modelo */&lt;/span&gt; &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;UsuarioService&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt; &lt;span class="cm"&gt;/* lógica */&lt;/span&gt; &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;UsuarioRepository&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt; &lt;span class="cm"&gt;/* persistência */&lt;/span&gt; &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;UsuarioController&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt; &lt;span class="cm"&gt;/* API */&lt;/span&gt; &lt;span class="o"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  2. Anemic Domain Model
&lt;/h3&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight java"&gt;&lt;code&gt;&lt;span class="c1"&gt;// ⚠️ CUIDADO - Modelo anêmico (sem comportamento)&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;Conta&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="n"&gt;saldo&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;
    &lt;span class="c1"&gt;// apenas getters e setters&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;ContaService&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;sacar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;Conta&lt;/span&gt; &lt;span class="n"&gt;conta&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="n"&gt;valor&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="c1"&gt;// toda lógica aqui&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="c1"&gt;// ✅ MELHOR - Modelo rico&lt;/span&gt;
&lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;Conta&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;private&lt;/span&gt; &lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="n"&gt;saldo&lt;/span&gt;&lt;span class="o"&gt;;&lt;/span&gt;

    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;sacar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="n"&gt;valor&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;valor&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;compareTo&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;saldo&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
            &lt;span class="k"&gt;throw&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nf"&gt;SaldoInsuficienteException&lt;/span&gt;&lt;span class="o"&gt;();&lt;/span&gt;
        &lt;span class="o"&gt;}&lt;/span&gt;
        &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;saldo&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;saldo&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;subtract&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;valor&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;

    &lt;span class="kd"&gt;public&lt;/span&gt; &lt;span class="kt"&gt;void&lt;/span&gt; &lt;span class="nf"&gt;depositar&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="nc"&gt;BigDecimal&lt;/span&gt; &lt;span class="n"&gt;valor&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;saldo&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;saldo&lt;/span&gt;&lt;span class="o"&gt;.&lt;/span&gt;&lt;span class="na"&gt;add&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;valor&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Conclusão
&lt;/h2&gt;

&lt;p&gt;Separation of Concerns não é apenas um princípio teórico - é uma ferramenta prática que torna nosso código:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;Mais fácil de entender&lt;/strong&gt; 🧠&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Mais fácil de manter&lt;/strong&gt; 🔧&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Mais fácil de testar&lt;/strong&gt; 🧪&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Mais fácil de escalar&lt;/strong&gt; 📈&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Mais fácil de reutilizar&lt;/strong&gt; ♻️&lt;/li&gt;
&lt;/ul&gt;

&lt;h3&gt;
  
  
  Lembre-se:
&lt;/h3&gt;

&lt;ol&gt;
&lt;li&gt;&lt;strong&gt;Cada classe deve ter uma razão para mudar&lt;/strong&gt;&lt;/li&gt;
&lt;li&gt;&lt;strong&gt;Cada método deve fazer uma coisa bem feita&lt;/strong&gt;&lt;/li&gt;
&lt;li&gt;&lt;strong&gt;Cada camada deve ter uma responsabilidade clara&lt;/strong&gt;&lt;/li&gt;
&lt;li&gt;&lt;strong&gt;Prefira composição sobre herança&lt;/strong&gt;&lt;/li&gt;
&lt;li&gt;&lt;strong&gt;Use interfaces para reduzir acoplamento&lt;/strong&gt;&lt;/li&gt;
&lt;/ol&gt;

&lt;h3&gt;
  
  
  Próximos Passos
&lt;/h3&gt;

&lt;ul&gt;
&lt;li&gt;Estude os princípios &lt;strong&gt;SOLID&lt;/strong&gt; (SoC é parte do S - Single Responsibility)&lt;/li&gt;
&lt;li&gt;Explore padrões de design como &lt;strong&gt;MVC&lt;/strong&gt;, &lt;strong&gt;MVP&lt;/strong&gt;, &lt;strong&gt;MVVM&lt;/strong&gt;
&lt;/li&gt;
&lt;li&gt;Pratique &lt;strong&gt;Domain-Driven Design (DDD)&lt;/strong&gt;
&lt;/li&gt;
&lt;li&gt;Aprenda sobre &lt;strong&gt;Arquitetura Hexagonal&lt;/strong&gt;
&lt;/li&gt;
&lt;li&gt;Experimente com &lt;strong&gt;Microserviços&lt;/strong&gt;
&lt;/li&gt;
&lt;/ul&gt;

&lt;h2&gt;
  
  
  Call to Action
&lt;/h2&gt;

&lt;p&gt;Agora olhe para seu código Java. Encontre aquela classe com 1000 linhas. Você sabe qual é.&lt;/p&gt;

&lt;p&gt;Comece pequeno:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;Extraia um método&lt;/li&gt;
&lt;li&gt;Depois extraia uma classe&lt;/li&gt;
&lt;li&gt;Depois separe em camadas&lt;/li&gt;
&lt;li&gt;Continue refatorando&lt;/li&gt;
&lt;/ol&gt;

&lt;p&gt;&lt;strong&gt;Roma não foi construída em um dia, e seu código limpo também não será.&lt;/strong&gt; Mas cada passo na direção certa conta!&lt;/p&gt;




&lt;p&gt;💬 Tem alguma dúvida ou quer compartilhar como aplica SoC em seus projetos Java? Deixe um comentário abaixo!&lt;/p&gt;

&lt;p&gt;⭐ Se este artigo foi útil, não esqueça de dar uma estrela e compartilhar com seus colegas desenvolvedores Jav&lt;/p&gt;

</description>
      <category>architecture</category>
      <category>java</category>
      <category>tutorial</category>
    </item>
    <item>
      <title>Configurando o Keycloak com SSL e integração ao banco de dados PostgreSQL</title>
      <dc:creator>Jhonathan dos reis</dc:creator>
      <pubDate>Fri, 14 Apr 2023 23:50:25 +0000</pubDate>
      <link>https://dev.to/jhonathandosreis/configurando-o-keycloak-com-ssl-e-integracao-ao-banco-de-dados-postgresql-3hl9</link>
      <guid>https://dev.to/jhonathandosreis/configurando-o-keycloak-com-ssl-e-integracao-ao-banco-de-dados-postgresql-3hl9</guid>
      <description>&lt;p&gt;Neste guia, você encontrará instruções detalhadas passo a passo para configurar e executar um servidor Keycloak, com suporte completo para SSL direcionado ao host, sem a necessidade de um proxy reverso como o Nginx.&lt;/p&gt;




&lt;h1&gt;
  
  
  Antecedentes e Escopo
&lt;/h1&gt;

&lt;p&gt;Encontrar informações atualizadas sobre tecnologias em constante evolução, como o Keycloak, pode ser um desafio, mesmo após pesquisar em fóruns, blogs e Stack Overflow. O autor deste artigo relata que não encontrou referências específicas para a versão estável 20.0.5, mas sim apenas para versões antigas. No entanto, após validar as informações contidas na documentação oficial, este artigo foi elaborado para fornecer um guia completo e atualizado sobre como configurar o Keycloak. As instruções foram testadas e comprovadas, garantindo um resultado bem-sucedido ao seguir os passos descritos.&lt;/p&gt;

&lt;p&gt;Além das instruções genéricas para configurar o Keycloak, este artigo fornece instruções detalhadas e passo a passo para integrar o SafeNet Keycloak Agent com o servidor Keycloak. Isso inclui o módulo e o tema de login do SafeNet Authentication Service, oferecendo uma solução completa e segura para os usuários.&lt;br&gt;
O objetivo principal dessas instruções é facilitar a configuração e reduzir o tempo necessário para criar uma demonstração, prova de conceito (PoC). Isso é alcançado fornecendo um guia completo e atualizado, com instruções detalhadas e passo a passo, testadas e comprovadas para garantir um resultado bem-sucedido.&lt;/p&gt;


&lt;h1&gt;
  
  
  Pré-requisitos
&lt;/h1&gt;

&lt;p&gt;Os seguintes pré-requisitos devem ser atendidos para seguir com êxito estas instruções:&lt;/p&gt;

&lt;p&gt;Ubuntu 20.04&lt;br&gt;
DNS (FQDN resolvível)&lt;br&gt;
Regras de FW/rede:&lt;br&gt;
22 (SSH)&lt;br&gt;
443 (SSL/TLS)&lt;br&gt;
80 (HTTP)&lt;/p&gt;


&lt;h1&gt;
  
  
  Geração de certificado com Lets Encrypt
&lt;/h1&gt;

&lt;p&gt;No host do Keycloak Server de destino, execute as seguintes etapas:&lt;/p&gt;

&lt;p&gt;1- SSH para o host Keycloak Server&lt;/p&gt;

&lt;p&gt;2- Execute o seguinte comando para instalar o Letsencrypt Certbot:&lt;/p&gt;

&lt;p&gt;&lt;code&gt;sudo snap install --classic certbot&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;3- Em seguida, execute o seguinte comando para garantir que o comando certbot agora possa ser executado:&lt;/p&gt;

&lt;p&gt;&lt;code&gt;sudo ln -s /snap/bin/certbot /usr/bin/certbot&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;4- Agora execute o Certbot para iniciar a geração do certificado:&lt;/p&gt;

&lt;p&gt;&lt;code&gt;sudo certbot certonly --standalone&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;Siga as instruções na tela para gerar um certificado SSL/TLS e uma chave privada.&lt;/p&gt;

&lt;p&gt;Agora você tem um arquivo fullchain.pem e um privkey.pem para usar com SSL/TLS&lt;/p&gt;


&lt;h1&gt;
  
  
  Instalar e configurar o Docker
&lt;/h1&gt;

&lt;p&gt;O modelo abaixo apresenta os comandos necessários para instalar a versão mais recente do Docker Engine. Certifique-se de verificar se há atualizações na documentação oficial antes de executar os comandos.&lt;/p&gt;

&lt;p&gt;1- Abra um terminal e atualize o índice de pacotes do apt:&lt;/p&gt;

&lt;p&gt;&lt;code&gt;sudo apt update&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;2- Instale o Docker:&lt;/p&gt;

&lt;p&gt;&lt;code&gt;sudo apt install docker.io&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;3- Verifique se o Docker foi instalado corretamente executando o seguinte comando:&lt;/p&gt;

&lt;p&gt;&lt;code&gt;docker --version&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;4- Inicie o serviço do Docker:&lt;/p&gt;

&lt;p&gt;&lt;code&gt;sudo systemctl start docker&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;5- Verifique o status do serviço Docker para garantir que ele esteja em execução:&lt;/p&gt;

&lt;p&gt;&lt;code&gt;sudo systemctl status docker&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;6- (Opcional) Para permitir que o Docker seja iniciado automaticamente na inicialização do sistema, execute o seguinte comando:&lt;/p&gt;

&lt;p&gt;&lt;code&gt;sudo systemctl enable docker&lt;/code&gt;&lt;/p&gt;


&lt;h1&gt;
  
  
  Instalar o Docker Compose
&lt;/h1&gt;

&lt;p&gt;Como etapa final da instalação/configuração do Docker, instalamos o Docker Compose.&lt;/p&gt;

&lt;p&gt;1- Verifique se o Docker está instalado e em execução. Você pode verificar isso executando o seguinte comando:&lt;/p&gt;

&lt;p&gt;&lt;code&gt;sudo docker version&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;2- Faça o download da versão mais recente do Docker Compose:&lt;/p&gt;

&lt;p&gt;&lt;code&gt;sudo curl -L "https://github.com/docker/compose/releases/download/1.29.2/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;3- Defina as permissões de execução para o binário do Docker Compose:&lt;/p&gt;

&lt;p&gt;&lt;code&gt;sudo chmod +x /usr/local/bin/docker-compose&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;4- Verifique se a instalação foi bem-sucedida executando o seguinte comando:&lt;/p&gt;

&lt;p&gt;&lt;code&gt;docker-compose --version&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;5- Para iniciar o Docker Compose, execute o seguinte comando:&lt;/p&gt;

&lt;p&gt;&lt;code&gt;sudo systemctl start docker-compose&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;6- Para habilitar o Docker Compose na inicialização do sistema, execute o seguinte comando:&lt;/p&gt;

&lt;p&gt;&lt;code&gt;sudo systemctl enable docker-compose&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;7- Para verificar o status do Docker Compose, execute o seguinte comando:&lt;/p&gt;

&lt;p&gt;&lt;code&gt;sudo systemctl status docker-compose&lt;/code&gt;&lt;/p&gt;


&lt;h1&gt;
  
  
  Pré-configuração do servidor Keycloak
&lt;/h1&gt;

&lt;p&gt;Após gerar os certificados e instalar e verificar o Docker, o próximo passo é mover ou manter os arquivos de certificado e outras configurações adicionais, como o tema SafeNet ou um tema personalizado, além de quaisquer plug-ins ou módulos, para os diretórios apropriados onde possam ser acessados ​​quando a solução for executada.&lt;/p&gt;

&lt;p&gt;1- Copie os .pem arquivos de certificado para um local onde possam ser lidos pelo Docker/Docker-Compose (observe o exemplo abaixo)&lt;/p&gt;

&lt;p&gt;2- Defina e teste as permissões para o arquivo acima para garantir que eles possam ser acessados:&lt;/p&gt;

&lt;p&gt;&lt;code&gt;sudo chmod 655 ./certs/*&lt;/code&gt;&lt;/p&gt;


&lt;h1&gt;
  
  
  Exemplos de arquivos e estrutura de arquivos
&lt;/h1&gt;

&lt;p&gt;Aqui está um exemplo de estrutura de arquivo que mostra a localização dos arquivos de certificado &lt;code&gt;fullchain.pem&lt;/code&gt;, chave &lt;code&gt;privkey.pem&lt;/code&gt;, um módulo personalizado &lt;code&gt;SafeNetOtpRealm.json&lt;/code&gt; e um tema personalizado &lt;code&gt;sas-login-ui&lt;/code&gt;. Esta estrutura de arquivo pode ser usada no arquivo de arquivo Docker Compose compartilhado com este repositório ou em outros casos semelhantes:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;.
├── certs
│   ├── fullchain.pem
│   └── privkey.pem
├── keycloak.yml
└── safenet
    ├── SafeNetOtpRealm.json
    └── sas-login-ui
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;blockquote&gt;
&lt;p&gt;&lt;code&gt;O Lets Encrypt não deve ser renomeado ou convertido para .crt!&lt;/code&gt;&lt;/p&gt;
&lt;/blockquote&gt;




&lt;h1&gt;
  
  
  Aqui está um exemplo de arquivo do Docker Compose
&lt;/h1&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;version: '3.7'

services:
  keycloak:
    container_name: keycloak
    image: quay.io/keycloak/keycloak:20.0.5 ou latest
    restart: always
    ports:
      - 8080:8080
      - 8443:8443
    environment:
      - KEYCLOAK_ADMIN=admin
      - KEYCLOAK_ADMIN_PASSWORD=admin
      - KEYCLOAK_IMPORT=/tmp/SafeNetOtpRealm.json
      - KEYCLOAK_DEFAULT_THEME=sas-login-ui
      - KC_DB=&amp;lt;banco-de-dados&amp;gt;
      - KC_DB_URL=jdbc:postgresql://&amp;lt;host-do-banco&amp;gt;:&amp;lt;porta&amp;gt;/keycloak
      - KC_DB_USERNAME=&amp;lt;sername-do-banco&amp;gt;
      - KC_DB_PASSWORD=&amp;lt;password-do-banco&amp;gt;
      - KC_HOSTNAME=&amp;lt;host-do-servidor&amp;gt;
      - KC_HTTP_PORT=&amp;lt;porta-http&amp;gt;
      - KC_HTTPS_PORT=&amp;lt;porta-https&amp;gt;
      - KC_HTTPS_CERTIFICATE_FILE=/etc/x509/https/tls.crt
      - KC_HTTPS_CERTIFICATE_KEY_FILE=/etc/x509/https/tls.key
      - JAVA_OPTS_APPEND="-D keycloak.profile.feature.upload_script=enabled"
    volumes:
      - ./safenet/SafeNetOtpRealm.json:/tmp/SafeNetOtpRealm.json
      - ./safenet/sas-login-ui/:/opt/jboss/keycloak/themes/sas-login-ui/
      - ./certs/fullchain.pem:/etc/x509/https/tls.crt
      - ./certs/privkey.pem:/etc/x509/https/tls.key
    command: start-dev
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;






&lt;h1&gt;
  
  
  Implantando e testando o servidor Keycloak
&lt;/h1&gt;

&lt;p&gt;Assumindo que os arquivos estejam nos diretórios corretos e as permissões estejam configuradas corretamente, agora você está pronto para executar e testar o serviço!&lt;/p&gt;

&lt;p&gt;1- Execute o Docker com Keycloak:&lt;/p&gt;

&lt;p&gt;&lt;code&gt;sudo docker-compose -f keycloak.yml up&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;2- Para verificar se tudo está funcionando, abra um navegador e navegue até o host keycloak usando, &lt;/p&gt;

&lt;p&gt;&lt;code&gt;https://&lt;/code&gt; por exemplo &lt;code&gt;https://keycloak.tech.tk&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;A página principal do Keycloak é exibida sem erros de certificado ✔&lt;/p&gt;

&lt;p&gt;Clicar no login do Keycloak do console de administração é exibido com o tema definido (opcional) ✔&lt;/p&gt;

&lt;p&gt;&lt;a href="https://media.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fja5dbl3g4rhrs7ps3569.png" class="article-body-image-wrapper"&gt;&lt;img src="https://media.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fja5dbl3g4rhrs7ps3569.png" alt="Image description"&gt;&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;&lt;code&gt;A navegação para o host do Keycloak por HTTPS deve funcionar sem erros ou avisos&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;&lt;a href="https://media.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2F4x5m75crct4jwm8p24ng.png" class="article-body-image-wrapper"&gt;&lt;img src="https://media.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2F4x5m75crct4jwm8p24ng.png" alt="Image description"&gt;&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;&lt;code&gt;Selecionar para fazer login deve exibir o tema (se usado)&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;&lt;a href="https://media.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2F3n5jlyazwkzxvdhopuvt.png" class="article-body-image-wrapper"&gt;&lt;img src="https://media.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2F3n5jlyazwkzxvdhopuvt.png" alt="Image description"&gt;&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;&lt;code&gt;Painel informando a versão utilizada&lt;/code&gt;&lt;/p&gt;




&lt;p&gt;Em resumo, a configuração do Keycloak com SSL e integração ao banco de dados PostgreSQL pode ser um processo desafiador, mas seguindo os passos descritos neste artigo, é possível realizar com sucesso. Certificar-se de que todos os arquivos estão nos diretórios corretos e que as permissões adequadas foram definidas é fundamental. Além disso, é importante lembrar que, ao configurar um serviço de autenticação, como o Keycloak, é essencial garantir que ele seja seguro e protegido. Com isso em mente, este artigo ofereceu um guia abrangente e útil para quem deseja configurar o Keycloak com SSL e integração ao banco de dados PostgreSQL. Esperamos que este guia tenha sido útil e que você tenha sucesso em sua configuração!&lt;/p&gt;




&lt;h1&gt;
  
  
  Apêndice
&lt;/h1&gt;

&lt;p&gt;Nesta seção, examino ferramentas e comandos úteis ao levantar e gerenciar o Keycloak no Docker.&lt;/p&gt;

&lt;p&gt;Verificando o log em busca de erros&lt;br&gt;
Se as coisas não estiverem funcionando, verifique o log:&lt;/p&gt;

&lt;p&gt;&lt;code&gt;sudo docker logs keycloak -f&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;Start, Stop e Remove do container&lt;br&gt;
A seguir estão alguns comandos úteis para gerenciar o contêiner keycloak depois de implantado com o Docker.&lt;/p&gt;

&lt;p&gt;Start&lt;/p&gt;

&lt;p&gt;&lt;code&gt;sudo docker start keycloak&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;Stop&lt;/p&gt;

&lt;p&gt;&lt;code&gt;sudo docker stop keycloak&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;Remove&lt;/p&gt;

&lt;p&gt;&lt;code&gt;sudo docker rm keycloak&lt;/code&gt;&lt;/p&gt;

</description>
    </item>
  </channel>
</rss>
