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Sharath Kumar
Sharath Kumar

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Servlets and JSP Concepts in Java

#servlets #jsp #ashokit #java

Servlets and JavaServer Pages (JSP) are core technologies used in Java web development to create dynamic and interactive web applications. They form the foundation of many enterprise-level applications and are widely used in backend development. Understanding Servlets and JSP concepts helps developers build scalable, secure, and high-performance web applications.

What are Java Servlets?

A Servlet is a Java program that runs on a web server and handles client requests and responses. Servlets are mainly used to process HTTP requests, interact with databases, and generate dynamic web content.

Servlets operate within a servlet container such as Apache Tomcat, which manages their lifecycle and execution.

Key Features of Servlets

  • Platform independent
  • Efficient request handling
  • Better performance compared to CGI
  • Supports session management
  • Secure and scalable

Servlet Architecture

The servlet architecture follows a client-server model:

  1. Client sends HTTP request through browser
  2. Web server forwards request to Servlet container
  3. Servlet processes request logic
  4. Response is generated and sent back to client

Servlet Life Cycle

The servlet lifecycle consists of three main methods:

1. init()

Called once when the servlet is initialized.

2. service()

Handles incoming client requests (GET, POST, etc.).

3. destroy()

Called before servlet removal to release resources.

What is JSP (JavaServer Pages)?

JSP is a technology used to create dynamic web pages using HTML combined with Java code. JSP simplifies UI development by separating presentation logic from business logic.

Unlike Servlets, which require Java code for HTML generation, JSP allows developers to write HTML directly with embedded Java.

JSP Components

1. Directives

Provide instructions to the JSP container.
Example:

<%@ page language="java" %>
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2. Scriptlets

Used to write Java code inside JSP.

<%
out.println("Welcome to JSP");
%>
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3. Expressions

Used to display output directly.

<%= "Hello User" %>
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4. JSP Actions

Used for reusable components and JavaBeans interaction.

Difference Between Servlets and JSP

Feature Servlets JSP
Usage Business logic Presentation layer
Coding Style Java-heavy HTML-friendly
Performance Faster processing Converted into servlet internally
Development Complex UI creation Easy UI design

Working Together: MVC Architecture

Servlets and JSP are commonly used together in the MVC (Model-View-Controller) pattern:

  • Model → Business logic & database
  • View → JSP pages
  • Controller → Servlets

This separation improves maintainability and scalability of applications.

Advantages of Servlets and JSP

  • Reusable components
  • Improved performance
  • Easy database integration
  • Supports session tracking
  • Ideal for enterprise web applications

Best Practices

  • Use Servlets for business logic only
  • Use JSP mainly for UI rendering
  • Follow MVC architecture
  • Avoid Java code inside JSP (use JSTL/EL)
  • Manage sessions securely

Conclusion

Servlets and JSP concepts are essential for Java web development. They enable developers to build dynamic, database-driven web applications efficiently. Learning these technologies provides a strong foundation for advanced frameworks like Spring and Spring Boot.

If you want to gain real industry experience and work on live applications, enrolling in Best Java Real Time Projects Online Training is the perfect choice. Ashok IT, located in Hyderabad, offers both online and offline training programs with real-time projects, expert trainers, and placement-focused learning.

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