GenericServlet

title: GenericServlet in Java description: GenericServlet class ka use aur HttpServlet se fark

GenericServlet ek abstract class hai jo Servlet interface implement karti hai. Yeh protocol-independent servlet hai — HTTP ke alawa bhi kisi protocol ke liye use ho sakti hai.

GenericServlet ka Structure

java exampleWoHoTech

public abstract class GenericServlet implements Servlet, ServletConfig, Serializable {
    // Ye methods already implement kiye hain:
    public void init(ServletConfig config)
    public void destroy()
    public ServletConfig getServletConfig()
    public String getServletInfo()

    // Ye abstract hai — hume implement karna padta hai:
    public abstract void service(ServletRequest req, ServletResponse res);
}

GenericServlet Example

java exampleWoHoTech

import jakarta.servlet.*;
import java.io.*;

public class MyGenericServlet extends GenericServlet {

    @Override
    public void service(ServletRequest request, ServletResponse response)
            throws ServletException, IOException {

        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        out.println("<html><body>");
        out.println("<h1>GenericServlet Response</h1>");
        out.println("<p>Yeh GenericServlet se aaya hai</p>");
        out.println("</body></html>");
    }
}

init() aur destroy() override karna

java exampleWoHoTech

public class LifecycleGenericServlet extends GenericServlet {

    @Override
    public void init() throws ServletException {
        // no-arg init — GenericServlet provide karta hai
        System.out.println("Servlet initialized");
    }

    @Override
    public void service(ServletRequest req, ServletResponse res)
            throws ServletException, IOException {
        res.getWriter().println("Service called");
    }

    @Override
    public void destroy() {
        System.out.println("Servlet destroyed");
    }
}

ServletRequest Methods (GenericServlet mein milte hain)

java exampleWoHoTech

public void service(ServletRequest req, ServletResponse res) throws Exception {
    req.getParameter("name")           // Form parameter
    req.getAttribute("key")            // Request attribute
    req.getRemoteAddr()                // Client IP
    req.getContentType()               // Content type
    req.getContentLength()             // Content length
    req.getServerName()                // Server name
    req.getServerPort()                // Server port
}

GenericServlet vs HttpServlet

	GenericServlet	HttpServlet
--	--	--
Protocol	Protocol independent	HTTP specific
Method	`service()` override	`doGet()`, `doPost()` override
Use case	Non-HTTP protocols	Web applications
Common use	Rare	Very common

Note: Real web applications mein HttpServlet use karte hain. GenericServlet sirf tab use hota hai jab HTTP ke alawa koi aur protocol handle karna ho.

title: GenericServlet in Java description: GenericServlet class ka use aur HttpServlet se fark

GenericServlet ek abstract class hai jo Servlet interface implement karti hai. Yeh protocol-independent servlet hai — HTTP ke alawa bhi kisi protocol ke liye use ho sakti hai.

GenericServlet ka Structure

java exampleWoHoTech

public abstract class GenericServlet implements Servlet, ServletConfig, Serializable {
    // Ye methods already implement kiye hain:
    public void init(ServletConfig config)
    public void destroy()
    public ServletConfig getServletConfig()
    public String getServletInfo()

    // Ye abstract hai — hume implement karna padta hai:
    public abstract void service(ServletRequest req, ServletResponse res);
}

GenericServlet Example

java exampleWoHoTech

import jakarta.servlet.*;
import java.io.*;

public class MyGenericServlet extends GenericServlet {

    @Override
    public void service(ServletRequest request, ServletResponse response)
            throws ServletException, IOException {

        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        out.println("<html><body>");
        out.println("<h1>GenericServlet Response</h1>");
        out.println("<p>Yeh GenericServlet se aaya hai</p>");
        out.println("</body></html>");
    }
}

init() aur destroy() override karna

java exampleWoHoTech

public class LifecycleGenericServlet extends GenericServlet {

    @Override
    public void init() throws ServletException {
        // no-arg init — GenericServlet provide karta hai
        System.out.println("Servlet initialized");
    }

    @Override
    public void service(ServletRequest req, ServletResponse res)
            throws ServletException, IOException {
        res.getWriter().println("Service called");
    }

    @Override
    public void destroy() {
        System.out.println("Servlet destroyed");
    }
}

ServletRequest Methods (GenericServlet mein milte hain)

java exampleWoHoTech

public void service(ServletRequest req, ServletResponse res) throws Exception {
    req.getParameter("name")           // Form parameter
    req.getAttribute("key")            // Request attribute
    req.getRemoteAddr()                // Client IP
    req.getContentType()               // Content type
    req.getContentLength()             // Content length
    req.getServerName()                // Server name
    req.getServerPort()                // Server port
}

GenericServlet vs HttpServlet

	GenericServlet	HttpServlet
--	--	--
Protocol	Protocol independent	HTTP specific
Method	`service()` override	`doGet()`, `doPost()` override
Use case	Non-HTTP protocols	Web applications
Common use	Rare	Very common

Note: Real web applications mein HttpServlet use karte hain. GenericServlet sirf tab use hota hai jab HTTP ke alawa koi aur protocol handle karna ho.

GenericServlet

GenericServlet ka Structure

GenericServlet Example

init() aur destroy() override karna

ServletRequest Methods (GenericServlet mein milte hain)

GenericServlet vs HttpServlet

Continue learning this concept

GenericServlet

GenericServlet ka Structure

GenericServlet Example

init() aur destroy() override karna

ServletRequest Methods (GenericServlet mein milte hain)

GenericServlet vs HttpServlet

Continue learning this concept