The following code example demonstrates how to Display init Parameters Using a Servlet.

Problem Statement

Display a servlet that fetches init parameters from web.xml displaying user information.

Here is an example of a servlet that fetches init parameters from the web.xml file and displays user information.

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class UserInfoServlet extends HttpServlet {

  @Override
  protected void doGet(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {
    response.setContentType("text/html");
    PrintWriter out = response.getWriter();
    out.println("<html>");
    out.println("<head>");
    out.println("<title>User Information</title>");
    out.println("</head>");
    out.println("<body>");
    out.println("<h1>User Information</h1>");
    out.println("<p>Name: " + getInitParameter("name") + "</p>");
    out.println("<p>Age: " + getInitParameter("age") + "</p>");
    out.println("<p>City: " + getInitParameter("city") + "</p>");
    out.println("</body>");
    out.println("</html>");
  }
}

Likewise, Here is an example of the web.xml file.

<web-app>
  <servlet>
    <servlet-name>UserInfoServlet</servlet-name>
    <servlet-class>UserInfoServlet</servlet-class>
    <init-param>
      <param-name>name</param-name>
      <param-value>John Doe</param-value>
    </init-param>
    <init-param>
      <param-name>age</param-name>
      <param-value>30</param-value>
    </init-param>
    <init-param>
      <param-name>city</param-name>
      <param-value>New York</param-value>
    </init-param>
  </servlet>
  <servlet-mapping>
    <servlet-name>UserInfoServlet</servlet-name>
    <url-pattern>/user-info</url-pattern>
  </servlet-mapping>
</web-app>

In this example, the UserInfoServlet class handles GET requests. The servlet retrieves the init parameters name, age, and city using the getInitParameter method and displays the user information in an HTML page. The servlet is mapped to the /user-info URL pattern in the web.xml file.

Further Reading

Understanding Enterprise Java Beans

Java Practice Exercise

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