Do we need to override service() method?
In Java servlets, the service() method is responsible for handling requests from clients. When a client makes a request to a servlet, the servlet container calls the service() method. This method then determines the type of request (GET, POST, etc.) and dispatches it to the appropriate handler method (doGet(), doPost(), etc.).

Table of Contents
Default Behavior of service()
The service() method is defined in the HttpServlet class, which is part of the Java Servlet API. By default, HttpServlet’s service() method delegates requests to the appropriate method based on the HTTP request type:
- GET requests are handled by the doGet() method.
- POST requests are handled by the doPost() method.
- PUT requests are handled by the doPut() method.
- DELETE requests are handled by the doDelete() method, and so on.
When to Override service()
In most cases, you don’t need to override the service() method directly. Instead, you typically override the doGet(), doPost(), or other HTTP-specific methods to handle different types of requests.
However, there are certain scenarios where you might want to override the service() method:
- Unified Handling: Â If you want to handle all types of HTTP requests in a unified manner, overriding service() allows you to manage all request types in one method.
- Custom Dispatching: Â If you need custom logic to determine how to dispatch requests (e.g., based on request parameters), you might override service() to implement this logic.
- Pre/Post Processing: Â If you want to perform certain actions before or after processing any request type, overriding service() allows you to include this logic centrally.
Let’s illustrate both scenarios: the typical way of handling requests by overriding doGet() and doPost(), and the scenario where we override service().
 Example 1: Overriding doGet() and doPost()
java
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet("/example1")
public class ExampleServlet1 extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
response.getWriter().println("<html><body>");
response.getWriter().println("<h2>Handling GET Request</h2>");
response.getWriter().println("</body></html>");
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
response.getWriter().println("<html><body>");
response.getWriter().println("<h2>Handling POST Request</h2>");
response.getWriter().println("</body></html>");
}
}
2. Servlet Code:
java
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet("/example2")
public class ExampleServlet2 extends HttpServlet {
@Override
protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
response.getWriter().println("<html><body>");
String method = request.getMethod();
if ("GET".equalsIgnoreCase(method)) {
response.getWriter().println("<h2>Handling GET Request via service()</h2>");
} else if ("POST".equalsIgnoreCase(method)) {
response.getWriter().println("<h2>Handling POST Request via service()</h2>");
} else {
response.getWriter().println("<h2>Handling Other Request via service()</h2>");
}
response.getWriter().println("</body></html>");
}
}
Explanation of the override service () method
- Example 1 (Overriding doGet() and doPost()): The servlet overrides doGet() and doPost() methods to handle GET and POST requests separately. This is the typical and recommended approach for handling specific HTTP request types.
- Example 2 (Overriding service()): The servlet overrides the service() method to handle all request types in a unified manner. The method checks the request type (GET, POST, etc.) and generates a response accordingly. This approach can be useful when you need centralized handling or custom dispatching logic.