authentication filter in web api code example

Example 1: Implement Authentication filter using filter API

//Servlet file
import java.io.*;

import javax.servlet.http.HttpServlet;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ServletFilter extends HttpServlet {
    @Override
    public void doGet(HttpServletRequest res, HttpServletResponse resp) throws IOException, ServletException {
        resp.setContentType("text/html;charset=UTF-8");
        PrintWriter out = resp.getWriter();
        String str = res.getParameter("name");
        out.print("<h1>Hello " + str + "</h1><h2>You have sucessfully logged in....</h2>");

    }

}

Example 2: Implement Authentication filter using filter API

<!-- XML File -->
<?xml version="1.0" encoding="UTF-8"?>
<web-app>

    <servlet>
    <servlet-name>ServletFilter</servlet-name>
    <servlet-class>ServletFilter</servlet-class>
    </servlet>
 <welecome-file-list>
          <welcome-file>index.html</welcome-file>
    </welecome-file-list>
  <servlet-mapping>
    <servlet-name>ServletFilter</servlet-name>
    <url-pattern>/filtering</url-pattern>
  </servlet-mapping>
  
 <filter>
  <filter-name>f1</filter-name>
  <filter-class>MyFilter</filter-class>
 </filter>

 <filter-mapping>
  <filter-name>f1</filter-name>
  <url-pattern>/filtering</url-pattern>
 </filter-mapping>
  

</web-app>