I want to check whether the authorized user/not in SERVLET. Login.html
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>Login page</title>
</head>
<body>
<table>
</table>
<form action="Check.java" >
USERNAME:<input type="text" value="name"><br><br>
PASSWORD:<input type="password" value="password"><br><br>
 <button style="color: #ff3399">SUBMIT</button>
</form>
</body>
</html>
Check.java
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class Check extends HttpServlet {
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String n=request.getParameter("name");
String p=request.getParameter("password");
if(p.equals("servlet")){
RequestDispatcher rd=request.getRequestDispatcher("servlet2");
rd.forward(request, response);
}
else{
out.print("Sorry UserName or Password Error!");
RequestDispatcher rd=request.getRequestDispatcher("/Login.html");
rd.include(request, response);
}
}
}
WelcomeServlet.java
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class WelcomeServlet extends HttpServlet {
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String n=request.getParameter("name");
out.print("Welcome "+n);
}
}
Web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
<display-name>REALPROJECT</display-name>
<servlet>
<servlet-name>Check</servlet-name>
<servlet-class>Check</servlet-class>
</servlet>
<servlet>
<servlet-name>WelcomeServlet</servlet-name>
<servlet-class>WelcomeServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>Check</servlet-name>
<url-pattern>/servlet1</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>WelcomeServlet</servlet-name>
<url-pattern>/servlet2</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>Login.html</welcome-file>
</welcome-file-list>
</web-app>
MY ERROR ARE:
HTTP Status 500 -
type Exception report
message
description The server encountered an internal error that prevented it from fulfilling this request.
exception
java.lang.NullPointerException
Check.doPost(Check.java:17)
javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.70 logs.
