Servlet - Fetching Result

A Servlet is a server-side Java program used to handle client requests and generate dynamic responses. Fetching Result in Servlet refers to retrieving form data from the client using request.getParameter() and processing it on the server. The processed data is then sent back as an HTTP response, usually in HTML format.

This mechanism is mainly used to capture user inputs like name, age, email, or any form data submitted from the browser.
It plays a key role in connecting frontend HTML forms with backend Java logic for dynamic web applications.
The fetched values can further be validated, processed, or stored in a database before sending the final response.

Steps to Fetch Result in Servlet

Follow the given steps to fetch a result from Html form to your browser.

Step 1: Create HTML Form

HTML form is used to take input from the user and send it to the servlet.

index.html

HTML

<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>Form</title>
</head>
<body>
<form action="GFGServletFetchResult" style="font-size: 25px;">
Enter your name: <input type="text" name="name" placeholder="Enter your name here"><br>
<button type="submit">Submit and go to Servlet</button>
</form>

</body>
</html>

Step 2: Request Sent to Servlet

On form submission, data is passed in the request URL.

/GFGServletFetchResult?name=GeeksForGeeks

Step 3: Servlet Receives Request

Servlet handles the request using doGet() or doPost() method.

protected void doGet (HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// working code
}

Step 4: Fetch Data from Request

Data is retrieved from the request object using getParameter().

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

Step 5: Type Conversion (If Required)

If numeric input is sent, convert it from String.

Step 6: Generate Response

Servlet prepares output using PrintWriter.

PrintWriter out = response.getWriter();
out.println("<h1>Welcome " + name + "</h1>");

Step 7: Response Sent to Browser

Final processed result is displayed in the client browser.

Output:

Note: In the following code, logic is written in doGet() method because, in the (above) HTML form, the method is "get" by default as the method is not explicitly mentioned as the post in the HTML form.

GFGServlet1.java

Java

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

// Annotation
@WebServlet("/GFGServletFetchResult")

// Main class
// Extending HttpServlet class
public class GFGServletFetchResult extends HttpServlet {

    private static final long serialVersionUID = 1L;

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

        PrintWriter out = response.getWriter();
        String name = request.getParameter("name");
        out.println("<!DOCTYPE html>");
        out.println("<html>");
        out.println("<head>");
        out.println("<title>Result Servlet</title>");
        out.println("<body>");
        out.println("<h1>Welcome " + name + "!</h1>");
        out.println("</body>");
        out.println("</head>");
        out.println("</html>");
    }

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

        doGet(request, response);
    }
}