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HttpServlet

Last Updated : 26 May, 2026

title: HttpServlet in Java

Servlets JSP92 words5 headingsTables includedExamples included

title: HttpServlet in Java description: HttpServlet class ka complete guide

HttpServlet ek abstract class hai jo GenericServlet ko extend karti hai. HTTP protocol ke liye specifically design ki gayi hai. Web applications mein yahi use hoti hai.

HttpServlet ke HTTP Methods

Method	HTTP Verb	Use
`doGet()`	GET	Data fetch karna
`doPost()`	POST	Data submit karna
`doPut()`	PUT	Resource update karna
`doDelete()`	DELETE	Resource delete karna
`doHead()`	HEAD	Headers only, no body
`doOptions()`	OPTIONS	Supported methods check

Basic HttpServlet Example

java exampleWoHoTech

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

@WebServlet("/greet")
public class GreetServlet extends HttpServlet {

    // GET request handle karna
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        String name = request.getParameter("name");
        if (name == null) name = "Guest";

        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();

        out.println("<!DOCTYPE html>");
        out.println("<html><head><title>Greet</title></head><body>");
        out.println("<h1>Namaste, " + name + "!</h1>");
        out.println("</body></html>");
    }

    // POST request handle karna
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        String name = request.getParameter("name");
        String email = request.getParameter("email");

        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();

        out.println("<html><body>");
        out.println("<h2>Form Submit hua!</h2>");
        out.println("<p>Name: " + name + "</p>");
        out.println("<p>Email: " + email + "</p>");
        out.println("</body></html>");
    }
}

HttpServletRequest — Common Methods

java exampleWoHoTech

protected void doGet(HttpServletRequest req, HttpServletResponse res) throws Exception {

    // Parameters
    req.getParameter("username")           // Single value
    req.getParameterValues("hobbies")      // Multiple values (checkbox)
    req.getParameterMap()                  // All params as Map

    // Headers
    req.getHeader("User-Agent")
    req.getHeader("Authorization")
    req.getHeaderNames()                   // All header names

    // URL Info
    req.getMethod()                        // "GET" or "POST"
    req.getRequestURI()                    // "/app/greet"
    req.getContextPath()                   // "/app"
    req.getServletPath()                   // "/greet"
    req.getQueryString()                   // "name=Ram&age=20"

    // Client Info
    req.getRemoteAddr()                    // Client IP
    req.getRemoteHost()                    // Client host

    // Session
    req.getSession()                       // Get/create session
    req.getSession(false)                  // Get only if exists

    // Attributes
    req.setAttribute("key", value)
    req.getAttribute("key")
    req.removeAttribute("key")

    // Dispatch
    req.getRequestDispatcher("/result.jsp").forward(req, res);
}

HttpServletResponse — Common Methods

java exampleWoHoTech

protected void doGet(HttpServletRequest req, HttpServletResponse res) throws Exception {

    // Content type
    res.setContentType("text/html;charset=UTF-8");
    res.setContentType("application/json");

    // Status codes
    res.setStatus(200);                          // OK
    res.setStatus(HttpServletResponse.SC_OK);    // Same
    res.sendError(404, "Not Found");

    // Headers
    res.setHeader("Cache-Control", "no-cache");
    res.setIntHeader("Content-Length", 100);
    res.setDateHeader("Last-Modified", System.currentTimeMillis());

    // Cookies
    res.addCookie(new Cookie("userId", "123"));

    // Writers/Streams
    PrintWriter out = res.getWriter();           // Text
    OutputStream os = res.getOutputStream();     // Binary

    // Redirect
    res.sendRedirect("/login");
    res.sendRedirect("https://google.com");
}

JSON Response (REST style)

java exampleWoHoTech

@WebServlet("/api/user")
public class UserApiServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse res)
            throws ServletException, IOException {

        res.setContentType("application/json");
        res.setCharacterEncoding("UTF-8");

        String json = "{\"id\":1,\"name\":\"Ram\",\"age\":25}";
        res.getWriter().write(json);
    }
}

Exam Focus

Revise definitions, diagrams, examples, and short-answer points for HttpServlet.

Interview Use

Prepare one clear explanation, one practical example, and one common mistake for this Java topic.

Search Terms

java, java programming, core java, java master course, java notes, master, course, servlets

Continue learning this concept

Servlets JSPGenericServlettitle: GenericServlet in Java Servlets JSPHttpServletRequest & HttpServletResponsetitle: Request and Response in Servlet Servlets JSPServlet Introductiontitle: Servlet Introduction Servlets JSPServlet Life Cycletitle: Servlet Life Cycle Servlets JSPCookies in Servlettitle: Cookies in Servlet Servlets JSPExpression Language ELtitle: Expression Language EL in JSP

PreviousGenericServlet NextJavaServer Pages JSP

Java Topics

HttpServlet

Last Updated : 26 May, 2026

title: HttpServlet in Java

Servlets JSP92 words5 headingsTables includedExamples included

title: HttpServlet in Java description: HttpServlet class ka complete guide

HttpServlet ek abstract class hai jo GenericServlet ko extend karti hai. HTTP protocol ke liye specifically design ki gayi hai. Web applications mein yahi use hoti hai.

HttpServlet ke HTTP Methods

Method	HTTP Verb	Use
`doGet()`	GET	Data fetch karna
`doPost()`	POST	Data submit karna
`doPut()`	PUT	Resource update karna
`doDelete()`	DELETE	Resource delete karna
`doHead()`	HEAD	Headers only, no body
`doOptions()`	OPTIONS	Supported methods check

Basic HttpServlet Example

java exampleWoHoTech

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

@WebServlet("/greet")
public class GreetServlet extends HttpServlet {

    // GET request handle karna
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        String name = request.getParameter("name");
        if (name == null) name = "Guest";

        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();

        out.println("<!DOCTYPE html>");
        out.println("<html><head><title>Greet</title></head><body>");
        out.println("<h1>Namaste, " + name + "!</h1>");
        out.println("</body></html>");
    }

    // POST request handle karna
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        String name = request.getParameter("name");
        String email = request.getParameter("email");

        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();

        out.println("<html><body>");
        out.println("<h2>Form Submit hua!</h2>");
        out.println("<p>Name: " + name + "</p>");
        out.println("<p>Email: " + email + "</p>");
        out.println("</body></html>");
    }
}

HttpServletRequest — Common Methods

java exampleWoHoTech

protected void doGet(HttpServletRequest req, HttpServletResponse res) throws Exception {

    // Parameters
    req.getParameter("username")           // Single value
    req.getParameterValues("hobbies")      // Multiple values (checkbox)
    req.getParameterMap()                  // All params as Map

    // Headers
    req.getHeader("User-Agent")
    req.getHeader("Authorization")
    req.getHeaderNames()                   // All header names

    // URL Info
    req.getMethod()                        // "GET" or "POST"
    req.getRequestURI()                    // "/app/greet"
    req.getContextPath()                   // "/app"
    req.getServletPath()                   // "/greet"
    req.getQueryString()                   // "name=Ram&age=20"

    // Client Info
    req.getRemoteAddr()                    // Client IP
    req.getRemoteHost()                    // Client host

    // Session
    req.getSession()                       // Get/create session
    req.getSession(false)                  // Get only if exists

    // Attributes
    req.setAttribute("key", value)
    req.getAttribute("key")
    req.removeAttribute("key")

    // Dispatch
    req.getRequestDispatcher("/result.jsp").forward(req, res);
}

HttpServletResponse — Common Methods

java exampleWoHoTech

protected void doGet(HttpServletRequest req, HttpServletResponse res) throws Exception {

    // Content type
    res.setContentType("text/html;charset=UTF-8");
    res.setContentType("application/json");

    // Status codes
    res.setStatus(200);                          // OK
    res.setStatus(HttpServletResponse.SC_OK);    // Same
    res.sendError(404, "Not Found");

    // Headers
    res.setHeader("Cache-Control", "no-cache");
    res.setIntHeader("Content-Length", 100);
    res.setDateHeader("Last-Modified", System.currentTimeMillis());

    // Cookies
    res.addCookie(new Cookie("userId", "123"));

    // Writers/Streams
    PrintWriter out = res.getWriter();           // Text
    OutputStream os = res.getOutputStream();     // Binary

    // Redirect
    res.sendRedirect("/login");
    res.sendRedirect("https://google.com");
}

JSON Response (REST style)

java exampleWoHoTech

@WebServlet("/api/user")
public class UserApiServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse res)
            throws ServletException, IOException {

        res.setContentType("application/json");
        res.setCharacterEncoding("UTF-8");

        String json = "{\"id\":1,\"name\":\"Ram\",\"age\":25}";
        res.getWriter().write(json);
    }
}

Exam Focus

Revise definitions, diagrams, examples, and short-answer points for HttpServlet.

Interview Use

Prepare one clear explanation, one practical example, and one common mistake for this Java topic.

Search Terms

java, java programming, core java, java master course, java notes, master, course, servlets

Continue learning this concept

PreviousGenericServlet NextJavaServer Pages JSP