Java Notes

Request and Response Objects

Complete guide to HttpServletRequest and HttpServletResponse objects - reading parameters, headers, handling request data, setting responses, and content types.

Overview

Every servlet method receives two objects:

HttpServletRequest — Contains all information about the client's request
HttpServletResponse — Used to send the response back to the client

These are the most important objects in servlet programming.

Getting Request Headers

java example

// Specific header
String userAgent = request.getHeader("User-Agent");
String contentType = request.getHeader("Content-Type");
String authorization = request.getHeader("Authorization");
String acceptLanguage = request.getHeader("Accept-Language");

// All headers
Enumeration<String> headerNames = request.getHeaderNames();
while (headerNames.hasMoreElements()) {
    String headerName = headerNames.nextElement();
    String headerValue = request.getHeader(headerName);
    System.out.println(headerName + ": " + headerValue);
}

// Integer and Date headers
int contentLength = request.getIntHeader("Content-Length");
long ifModifiedSince = request.getDateHeader("If-Modified-Since");

Request Information Methods

java example

@WebServlet("/request-info")
public class RequestInfoServlet extends HttpServlet {

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

        response.setContentType("text/html");
        PrintWriter out = response.getWriter();

        out.println("<h2>Request Information</h2>");
        out.println("<table border=\"1\">");
        out.println("<tr><td>Method</td><td>" + request.getMethod() + "</td></tr>");
        out.println("<tr><td>Request URI</td><td>" + request.getRequestURI() + "</td></tr>");
        out.println("<tr><td>Request URL</td><td>" + request.getRequestURL() + "</td></tr>");
        out.println("<tr><td>Context Path</td><td>" + request.getContextPath() + "</td></tr>");
        out.println("<tr><td>Servlet Path</td><td>" + request.getServletPath() + "</td></tr>");
        out.println("<tr><td>Path Info</td><td>" + request.getPathInfo() + "</td></tr>");
        out.println("<tr><td>Query String</td><td>" + request.getQueryString() + "</td></tr>");
        out.println("<tr><td>Protocol</td><td>" + request.getProtocol() + "</td></tr>");
        out.println("<tr><td>Scheme</td><td>" + request.getScheme() + "</td></tr>");
        out.println("<tr><td>Server Name</td><td>" + request.getServerName() + "</td></tr>");
        out.println("<tr><td>Server Port</td><td>" + request.getServerPort() + "</td></tr>");
        out.println("<tr><td>Remote Addr</td><td>" + request.getRemoteAddr() + "</td></tr>");
        out.println("<tr><td>Remote Host</td><td>" + request.getRemoteHost() + "</td></tr>");
        out.println("<tr><td>Content Type</td><td>" + request.getContentType() + "</td></tr>");
        out.println("<tr><td>Content Length</td><td>" + request.getContentLength() + "</td></tr>");
        out.println("<tr><td>Character Encoding</td><td>" + request.getCharacterEncoding() + "</td></tr>");
        out.println("</table>");
    }
}

Reading Request Body (JSON)

java example

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

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

        // Read JSON body
        StringBuilder sb = new StringBuilder();
        BufferedReader reader = request.getReader();
        String line;
        while ((line = reader.readLine()) != null) {
            sb.append(line);
        }
        String jsonBody = sb.toString();

        // Parse JSON (using a library like Gson or Jackson)
        // For simplicity, manual parsing shown here
        System.out.println("Received JSON: " + jsonBody);

        response.setContentType("application/json");
        response.setStatus(HttpServletResponse.SC_CREATED);
        response.getWriter().println("{\"status\": \"created\", \"received\": " + jsonBody + "}");
    }
}

Request Attributes (for forwarding data)

java example

// Setting attributes (in first servlet)
request.setAttribute("userList", users);
request.setAttribute("totalCount", users.size());
request.setAttribute("message", "Data loaded successfully");

// Getting attributes (in forwarded servlet/JSP)
List<User> users = (List<User>) request.getAttribute("userList");
int count = (int) request.getAttribute("totalCount");

// Remove attribute
request.removeAttribute("message");

HttpServletResponse — Sending Data to Client

Setting Response Content Type

java example

// HTML response
response.setContentType("text/html");

// JSON response
response.setContentType("application/json");

// Plain text
response.setContentType("text/plain");

// XML response
response.setContentType("application/xml");

// PDF file
response.setContentType("application/pdf");

// Set character encoding
response.setCharacterEncoding("UTF-8");

// Combined
response.setContentType("text/html;charset=UTF-8");

Writing Response Body

java example

// Using PrintWriter (for text/character data)
PrintWriter out = response.getWriter();
out.println("<html><body>Hello World</body></html>");

// Using OutputStream (for binary data — images, files)
ServletOutputStream os = response.getOutputStream();
byte[] fileData = Files.readAllBytes(Paths.get("/path/to/image.png"));
os.write(fileData);
os.flush();

⚠️ Important: You cannot use both getWriter() and getOutputStream() on the same response. Doing so throws IllegalStateException.

Setting Response Headers

java example

// Set headers
response.setHeader("X-Custom-Header", "CustomValue");
response.setHeader("Cache-Control", "no-cache, no-store, must-revalidate");
response.setHeader("Pragma", "no-cache");
response.setDateHeader("Expires", 0);

// Add headers (allows multiple values for same header)
response.addHeader("Set-Cookie", "theme=dark; Path=/");
response.addHeader("Set-Cookie", "lang=en; Path=/");

// Numeric headers
response.setIntHeader("Refresh", 5); // Refresh page every 5 seconds

Setting Status Codes

java example

// Success codes
response.setStatus(HttpServletResponse.SC_OK);              // 200
response.setStatus(HttpServletResponse.SC_CREATED);         // 201
response.setStatus(HttpServletResponse.SC_NO_CONTENT);      // 204

// Redirect codes
response.setStatus(HttpServletResponse.SC_MOVED_PERMANENTLY); // 301
response.sendRedirect("/new-location");                       // 302

// Client error codes
response.sendError(HttpServletResponse.SC_BAD_REQUEST, "Invalid input");      // 400
response.sendError(HttpServletResponse.SC_UNAUTHORIZED, "Login required");    // 401
response.sendError(HttpServletResponse.SC_FORBIDDEN, "Access denied");        // 403
response.sendError(HttpServletResponse.SC_NOT_FOUND, "Resource not found");   // 404

// Server error codes
response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Server error"); // 500

File Download Response

Example

@WebServlet("/download") public class FileDownloadServlet extends HttpServlet { @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String fileName = request.getParameter("file"); String filePath = getServletContext().getRealPath("/files/" + fileName); File file = new File(filePath); if (!file.exists()) { response.sendError(404, "File not found"); return; } // Set response headers for download response.setContentType("application/octet-stream"); response.setContentLength((int) file.length()); response.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\""); // Write file to response try (FileInputStream fis = new FileInputStream(file); ServletOutputStream os = response.getOutputStream()) { byte[] buffer = new byte[4096]; int bytesRead; while ((bytesRead = fis.read(buffer)) != -1) { os.write(buffer, 0, bytesRead); } } } }

Complete Request-Response Example

Example

@WebServlet("/api/search") public class SearchServlet extends HttpServlet { @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // Read request data String query = request.getParameter("q"); String page = request.getParameter("page"); String userAgent = request.getHeader("User-Agent"); String clientIP = request.getRemoteAddr(); // Validate input if (query == null || query.trim().isEmpty()) { response.setStatus(HttpServletResponse.SC_BAD_REQUEST); response.setContentType("application/json"); response.getWriter().println("{\"error\": \"Query parameter 'q' is required\"}"); return; } int pageNum = 1; if (page != null) { try { pageNum = Integer.parseInt(page); } catch (NumberFormatException e) { pageNum = 1; } } // Log the request log(String.format("Search: q=%s, page=%d, IP=%s, UA=%s", query, pageNum, clientIP, userAgent)); // Build response response.setContentType("application/json"); response.setCharacterEncoding("UTF-8"); response.setHeader("X-Request-IP", clientIP); response.setHeader("X-Page", String.valueOf(pageNum)); PrintWriter out = response.getWriter(); out.println("{"); out.println(" \"query\": \"" + query + "\","); out.println(" \"page\": " + pageNum + ","); out.println(" \"results\": ["); out.println(" {\"title\": \"Result 1\", \"url\": \"http://example.com/1\"},"); out.println(" {\"title\": \"Result 2\", \"url\": \"http://example.com/2\"}"); out.println(" ],"); out.println(" \"totalResults\": 42"); out.println("}"); } }

Request Methods Summary Table

Method	Returns	Description
`getParameter(name)`	String	Single form/query parameter
`getParameterValues(name)`	String[]	Multiple values for same param
`getParameterMap()`	Map	All parameters
`getHeader(name)`	String	HTTP header value
`getMethod()`	String	GET, POST, PUT, DELETE
`getRequestURI()`	String	URI path (no host)
`getRequestURL()`	StringBuffer	Full URL
`getContextPath()`	String	Application context
`getQueryString()`	String	Raw query string
`getRemoteAddr()`	String	Client IP address
`getReader()`	BufferedReader	Request body reader
`getInputStream()`	InputStream	Binary request body
`getAttribute(name)`	Object	Request attribute
`getSession()`	HttpSession	Session object
`getCookies()`	Cookie[]	All cookies

Response Methods Summary Table

Method	Purpose
`setContentType(type)`	Set MIME type
`setCharacterEncoding(enc)`	Set encoding
`setStatus(code)`	Set HTTP status
`sendError(code, msg)`	Send error response
`sendRedirect(url)`	302 redirect
`setHeader(name, value)`	Set response header
`addHeader(name, value)`	Add header (multi-value)
`getWriter()`	Get character writer
`getOutputStream()`	Get binary output stream
`addCookie(cookie)`	Add cookie to response
`setContentLength(len)`	Set content length

Common Mistakes

Calling getWriter() and getOutputStream() on same response — IllegalStateException
Writing response after sendRedirect() — Response already committed
Not checking null for getParameter() — NullPointerException
Not setting content type before writing — Browser may not render properly
Reading body in doGet() — GET requests typically don't have a body

🔥 Interview Questions

Q1. What are the important methods of HttpServletRequest?

Answer: getParameter() — form data, getAttribute()/setAttribute() — request attributes, getSession() — session access, getHeader() — HTTP headers, getMethod() — HTTP method, getRequestURI() — URI, getContextPath() — app context, getRemoteAddr() — client IP.

Q2. What is the difference between getParameter() and getAttribute()?

Answer: getParameter() — data that came from the client (form fields, query string), returns String, read-only. getAttribute() — server-side data sharing (between servlets via forward), returns Object, read-write via setAttribute().

Q3. What is the difference between Forward and Redirect?

Answer:

Feature	Forward	Redirect
Control	Server-side	Client-side (new request)
URL	Same (browser doesn't know)	Changes in browser
Request data	Preserved (same request)	Lost (new request)
Speed	Faster (single request)	Slower (two round-trips)
Use	Internal navigation	External URL, after POST

Q4. sendRedirect() vs RequestDispatcher.forward()?

Answer: sendRedirect("url") — sends a 302 response to the browser, the browser makes a new request. RequestDispatcher.forward(req, res) — handled internally by the server, the client is unaware. sendRedirect is used in the POST-Redirect-GET pattern.

Q5. Request Scope vs Session Scope vs Application Scope?

Answer: Request: Share data within a single request (between forwards). Session: Persist within a user session (login info). Application: Shared across all sessions (global config). As scope increases, memory usage and concurrency concerns increase.

Q6. How to set content type in HttpServletResponse?

Answer: response.setContentType("text/html") or response.setContentType("application/json"). This tells the browser how to parse the response. Set this BEFORE getting writer/output stream.

Q7. How to add headers in the Response?

Answer: response.setHeader("name", "value") — single value. response.addHeader("name", "value") — multiple values for the same header. Use setStatus() to set the HTTP status code. Common: Content-Type, Cache-Control, Location (redirect).

Q8. How to read the Request body (POST data)?

Answer: Form data: request.getParameter("field"). JSON body: request.getReader() gives a BufferedReader, read and parse JSON from it. Binary data: use request.getInputStream().

Q9. How to handle file upload in a servlet?

Answer: Use the @MultipartConfig annotation. Access the file using request.getPart("file") or request.getParts(). The Part interface provides filename, size, content type, and input stream.

Q10. What is Response buffering?

Answer: The response does not go to the client immediately — it is collected in a buffer. Set buffer size with response.setBufferSize(8192). Manually flush with response.flushBuffer(). The buffer automatically flushes when full or when the response is committed. Headers can only be set before commit.

Summary

In this chapter, we learned about Request and Response Objects in detail. Here are the key points:

Basic introduction to the concept and why it is needed
Syntax and structure with complete examples
Internal working and best practices
Real-world applications and use cases
Common mistakes and how to avoid them
How this topic is asked in interviews

To practice these concepts, write and run the code in your IDE and verify the output. Modify each example and experiment so that you deeply understand the concept.

Exam Focus

Revise definitions, diagrams, examples, and short-answer points for Request and Response Objects.

Interview Use

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

Search Terms

java-master-course, java master course, java, master, course, servlets, jsp, request

Continue learning this concept

Servlets JSPCookies in ServletsComplete guide to handling cookies in Java Servlets - creating, reading, modifying, deleting cookies, cookie attributes, and security best practices.Servlets JSPExpression Language (EL)Complete guide to JSP Expression Language (EL) - syntax, operators, implicit objects, accessing beans, collections, and EL functions for clean JSP development.Servlets JSPGenericServletUnderstanding GenericServlet abstract class in Java - protocol-independent servlet implementation, methods, and comparison with HttpServlet.Servlets JSPHttpServletComplete guide to HttpServlet class - HTTP-specific servlet implementation with doGet, doPost, doPut, doDelete methods and practical examples.Servlets JSPJSP IntroductionComplete introduction to JavaServer Pages (JSP) - how JSP works, JSP lifecycle, scripting elements, implicit objects, and building dynamic web pages.Servlets JSPJSP Tags and JSTLComplete guide to JSP tags including standard actions, JSTL core tags, formatting tags, SQL tags, custom tags, and tag files for building maintainable JSP applications.

PreviousMVC Architecture NextServlet Introduction

Java Notes

Request and Response Objects

Complete guide to HttpServletRequest and HttpServletResponse objects - reading parameters, headers, handling request data, setting responses, and content types.

Overview

Every servlet method receives two objects:

HttpServletRequest — Contains all information about the client's request
HttpServletResponse — Used to send the response back to the client

These are the most important objects in servlet programming.

Getting Request Headers

java example

// Specific header
String userAgent = request.getHeader("User-Agent");
String contentType = request.getHeader("Content-Type");
String authorization = request.getHeader("Authorization");
String acceptLanguage = request.getHeader("Accept-Language");

// All headers
Enumeration<String> headerNames = request.getHeaderNames();
while (headerNames.hasMoreElements()) {
    String headerName = headerNames.nextElement();
    String headerValue = request.getHeader(headerName);
    System.out.println(headerName + ": " + headerValue);
}

// Integer and Date headers
int contentLength = request.getIntHeader("Content-Length");
long ifModifiedSince = request.getDateHeader("If-Modified-Since");

Request Information Methods

java example

@WebServlet("/request-info")
public class RequestInfoServlet extends HttpServlet {

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

        response.setContentType("text/html");
        PrintWriter out = response.getWriter();

        out.println("<h2>Request Information</h2>");
        out.println("<table border=\"1\">");
        out.println("<tr><td>Method</td><td>" + request.getMethod() + "</td></tr>");
        out.println("<tr><td>Request URI</td><td>" + request.getRequestURI() + "</td></tr>");
        out.println("<tr><td>Request URL</td><td>" + request.getRequestURL() + "</td></tr>");
        out.println("<tr><td>Context Path</td><td>" + request.getContextPath() + "</td></tr>");
        out.println("<tr><td>Servlet Path</td><td>" + request.getServletPath() + "</td></tr>");
        out.println("<tr><td>Path Info</td><td>" + request.getPathInfo() + "</td></tr>");
        out.println("<tr><td>Query String</td><td>" + request.getQueryString() + "</td></tr>");
        out.println("<tr><td>Protocol</td><td>" + request.getProtocol() + "</td></tr>");
        out.println("<tr><td>Scheme</td><td>" + request.getScheme() + "</td></tr>");
        out.println("<tr><td>Server Name</td><td>" + request.getServerName() + "</td></tr>");
        out.println("<tr><td>Server Port</td><td>" + request.getServerPort() + "</td></tr>");
        out.println("<tr><td>Remote Addr</td><td>" + request.getRemoteAddr() + "</td></tr>");
        out.println("<tr><td>Remote Host</td><td>" + request.getRemoteHost() + "</td></tr>");
        out.println("<tr><td>Content Type</td><td>" + request.getContentType() + "</td></tr>");
        out.println("<tr><td>Content Length</td><td>" + request.getContentLength() + "</td></tr>");
        out.println("<tr><td>Character Encoding</td><td>" + request.getCharacterEncoding() + "</td></tr>");
        out.println("</table>");
    }
}

Reading Request Body (JSON)

java example

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

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

        // Read JSON body
        StringBuilder sb = new StringBuilder();
        BufferedReader reader = request.getReader();
        String line;
        while ((line = reader.readLine()) != null) {
            sb.append(line);
        }
        String jsonBody = sb.toString();

        // Parse JSON (using a library like Gson or Jackson)
        // For simplicity, manual parsing shown here
        System.out.println("Received JSON: " + jsonBody);

        response.setContentType("application/json");
        response.setStatus(HttpServletResponse.SC_CREATED);
        response.getWriter().println("{\"status\": \"created\", \"received\": " + jsonBody + "}");
    }
}

Request Attributes (for forwarding data)

java example

// Setting attributes (in first servlet)
request.setAttribute("userList", users);
request.setAttribute("totalCount", users.size());
request.setAttribute("message", "Data loaded successfully");

// Getting attributes (in forwarded servlet/JSP)
List<User> users = (List<User>) request.getAttribute("userList");
int count = (int) request.getAttribute("totalCount");

// Remove attribute
request.removeAttribute("message");

HttpServletResponse — Sending Data to Client

Setting Response Content Type

java example

// HTML response
response.setContentType("text/html");

// JSON response
response.setContentType("application/json");

// Plain text
response.setContentType("text/plain");

// XML response
response.setContentType("application/xml");

// PDF file
response.setContentType("application/pdf");

// Set character encoding
response.setCharacterEncoding("UTF-8");

// Combined
response.setContentType("text/html;charset=UTF-8");

Writing Response Body

java example

// Using PrintWriter (for text/character data)
PrintWriter out = response.getWriter();
out.println("<html><body>Hello World</body></html>");

// Using OutputStream (for binary data — images, files)
ServletOutputStream os = response.getOutputStream();
byte[] fileData = Files.readAllBytes(Paths.get("/path/to/image.png"));
os.write(fileData);
os.flush();

⚠️ Important: You cannot use both getWriter() and getOutputStream() on the same response. Doing so throws IllegalStateException.

Setting Response Headers

java example

// Set headers
response.setHeader("X-Custom-Header", "CustomValue");
response.setHeader("Cache-Control", "no-cache, no-store, must-revalidate");
response.setHeader("Pragma", "no-cache");
response.setDateHeader("Expires", 0);

// Add headers (allows multiple values for same header)
response.addHeader("Set-Cookie", "theme=dark; Path=/");
response.addHeader("Set-Cookie", "lang=en; Path=/");

// Numeric headers
response.setIntHeader("Refresh", 5); // Refresh page every 5 seconds

Setting Status Codes

java example

// Success codes
response.setStatus(HttpServletResponse.SC_OK);              // 200
response.setStatus(HttpServletResponse.SC_CREATED);         // 201
response.setStatus(HttpServletResponse.SC_NO_CONTENT);      // 204

// Redirect codes
response.setStatus(HttpServletResponse.SC_MOVED_PERMANENTLY); // 301
response.sendRedirect("/new-location");                       // 302

// Client error codes
response.sendError(HttpServletResponse.SC_BAD_REQUEST, "Invalid input");      // 400
response.sendError(HttpServletResponse.SC_UNAUTHORIZED, "Login required");    // 401
response.sendError(HttpServletResponse.SC_FORBIDDEN, "Access denied");        // 403
response.sendError(HttpServletResponse.SC_NOT_FOUND, "Resource not found");   // 404

// Server error codes
response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Server error"); // 500

File Download Response

Example

Complete Request-Response Example

Example

Request Methods Summary Table

Method	Returns	Description
`getParameter(name)`	String	Single form/query parameter
`getParameterValues(name)`	String[]	Multiple values for same param
`getParameterMap()`	Map	All parameters
`getHeader(name)`	String	HTTP header value
`getMethod()`	String	GET, POST, PUT, DELETE
`getRequestURI()`	String	URI path (no host)
`getRequestURL()`	StringBuffer	Full URL
`getContextPath()`	String	Application context
`getQueryString()`	String	Raw query string
`getRemoteAddr()`	String	Client IP address
`getReader()`	BufferedReader	Request body reader
`getInputStream()`	InputStream	Binary request body
`getAttribute(name)`	Object	Request attribute
`getSession()`	HttpSession	Session object
`getCookies()`	Cookie[]	All cookies

Response Methods Summary Table

Method	Purpose
`setContentType(type)`	Set MIME type
`setCharacterEncoding(enc)`	Set encoding
`setStatus(code)`	Set HTTP status
`sendError(code, msg)`	Send error response
`sendRedirect(url)`	302 redirect
`setHeader(name, value)`	Set response header
`addHeader(name, value)`	Add header (multi-value)
`getWriter()`	Get character writer
`getOutputStream()`	Get binary output stream
`addCookie(cookie)`	Add cookie to response
`setContentLength(len)`	Set content length

Common Mistakes

Calling getWriter() and getOutputStream() on same response — IllegalStateException
Writing response after sendRedirect() — Response already committed
Not checking null for getParameter() — NullPointerException
Not setting content type before writing — Browser may not render properly
Reading body in doGet() — GET requests typically don't have a body

🔥 Interview Questions

Q1. What are the important methods of HttpServletRequest?

Q2. What is the difference between getParameter() and getAttribute()?

Q3. What is the difference between Forward and Redirect?

Answer:

Feature	Forward	Redirect
Control	Server-side	Client-side (new request)
URL	Same (browser doesn't know)	Changes in browser
Request data	Preserved (same request)	Lost (new request)
Speed	Faster (single request)	Slower (two round-trips)
Use	Internal navigation	External URL, after POST

Q4. sendRedirect() vs RequestDispatcher.forward()?

Q5. Request Scope vs Session Scope vs Application Scope?

Q6. How to set content type in HttpServletResponse?

Answer: response.setContentType("text/html") or response.setContentType("application/json"). This tells the browser how to parse the response. Set this BEFORE getting writer/output stream.

Q7. How to add headers in the Response?

Q8. How to read the Request body (POST data)?

Answer: Form data: request.getParameter("field"). JSON body: request.getReader() gives a BufferedReader, read and parse JSON from it. Binary data: use request.getInputStream().

Q9. How to handle file upload in a servlet?

Answer: Use the @MultipartConfig annotation. Access the file using request.getPart("file") or request.getParts(). The Part interface provides filename, size, content type, and input stream.

Q10. What is Response buffering?

Summary

In this chapter, we learned about Request and Response Objects in detail. Here are the key points:

Basic introduction to the concept and why it is needed
Syntax and structure with complete examples
Internal working and best practices
Real-world applications and use cases
Common mistakes and how to avoid them
How this topic is asked in interviews

To practice these concepts, write and run the code in your IDE and verify the output. Modify each example and experiment so that you deeply understand the concept.

Exam Focus

Revise definitions, diagrams, examples, and short-answer points for Request and Response Objects.

Interview Use

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

Search Terms

java-master-course, java master course, java, master, course, servlets, jsp, request

Continue learning this concept

PreviousMVC Architecture NextServlet Introduction