What is Maven?And Pom.xml?

What is Maven in Spring Boot?

• Maven is a build automation and project management tool used in Java projects. In Spring Boot, Maven handles:

• Downloading dependencies (libraries/jars) automatically

• Compiling your Java code

• Running tests

• Packaging your app into a .jar or .war file

• Deploying your application

What Maven Actually Does

Maven mainly handles 3 things:

1. Dependency Management

It downloads required libraries automatically.

Example:
You want to use MySQL in Spring Boot.

Without Maven:

• search MySQL connector online
• download jar
• add to project manually

With Maven:

• just add this in pom.xml

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-j</artifactId>
    <version>8.3.0</version>
</dependency>

Maven downloads it automatically from the Maven repository.

1. Build Automation

Maven can:

• compile code
• run tests
• package project
• create .jar or .war

Instead of: javac Main.java

You simply run: mvn compile

To create a JAR: mvn package

1. Standard Project Structure

Maven forces a clean structure.

Example:

project-name/
│
├── src/
│   ├── main/
│   │   ├── java/
│   │   └── resources/
│   │
│   └── test/
│       └── java/
│
├── pom.xml

1. What is pom.xml ?

This is the heart of Maven.

POM = Project Object Model

It contains:

• project name
• dependencies
• plugins
• Java version
• build settings

Example:

<project xmlns="http://maven.apache.org/POM/4.0.0">

    <modelVersion>4.0.0</modelVersion>

    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>1.0</version>

    <dependencies>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>3.2.5</version>
        </dependency>

    </dependencies>

</project>

Important Maven Commands :

Command	Purpose
mvn compile	Compiles code
mvn test	Runs tests
mvn package	Creates JAR/WAR
mvn clean	Deletes old build files
mvn install	Installs into local repository