What is the difference between JSP, Servlet, and JDBC?

JSP (JavaServer Pages), Servlets, and JDBC (Java Database Connectivity) are all Java technologies commonly used in web development, but they serve different purposes within a web application. Here are the key differences between JSP, Servlets, and JDBC:

1. Purpose and Role:

   • JSP (JavaServer Pages):

     • Purpose: JSP is a technology for building dynamic web pages. It allows developers to embed Java code directly into HTML pages, making it easier to create dynamic content.
     • Role: JSP is primarily used for the presentation layer of a web application. It is often used to generate HTML or other markup language content dynamically.

   • Servlets:

     • Purpose: Servlets are Java classes that handle HTTP requests and responses. They provide a server-side processing model and are part of the Java EE (Enterprise Edition) or Jakarta EE specification.
     • Role: Servlets are responsible for handling the business logic, processing user input, interacting with databases, and generating dynamic content for web applications.

   • JDBC (Java Database Connectivity):

     • Purpose: JDBC is a Java API that provides a standard interface for connecting to relational databases and executing SQL queries.
     • Role: JDBC is used for database access in Java applications. It allows developers to interact with databases, perform CRUD (Create, Read, Update, Delete) operations, and retrieve results.

2. Layer in a Web Application:

   • JSP:

     • JSP is typically part of the presentation layer in a web application. It focuses on generating dynamic content to be displayed in the user's web browser.

   • Servlets:

     • Servlets can be part of both the presentation and business logic layers. They handle requests, process data, and often act as controllers in a Model-View-Controller (MVC) architecture.

   • JDBC:

     • JDBC is part of the data access layer in a web application. It is responsible for connecting to a database, executing SQL queries, and managing interactions with the database.

3. Code Structure and Syntax:

   • JSP:

     • JSP pages use a combination of HTML and Java code. Java code is embedded using special tags (<% %>), and JSP expressions (${}) are used to output dynamic data in the HTML.

   • Servlets:

     • Servlets are Java classes that extend the HttpServlet class. They override methods such as doGet() or doPost() to handle specific HTTP requests. Servlets use Java code to process requests and generate responses.

   • JDBC:

     • JDBC involves writing Java code to connect to a database, create PreparedStatement or Statement objects, execute SQL queries, and process results. It often requires managing connections, transactions, and exception handling.

4. Interaction with the Client:

   • JSP:

     • JSP is focused on generating dynamic content to be sent to the client's web browser. It is often used to create HTML pages dynamically.

   • Servlets:

     • Servlets handle HTTP requests and generate responses. They can generate dynamic content, handle form submissions, and manage session data.

   • JDBC:

     • JDBC is not directly involved in the interaction with the client. It is used for database operations and interacts with the database server.

In summary, JSP, Servlets, and JDBC play distinct roles in a Java web application. JSP is primarily used for generating dynamic content in the presentation layer, Servlets handle the business logic and HTTP requests, and JDBC facilitates database access in the data access layer. Together, they contribute to the development of a complete and functional web application.