Facing Issue in implementing Listeners and Filters

[Mohit G Gupta]

I have coded a small example that shows various listeners and filter invocation.
The issues are:

1. I am unable to see any of the system.out.println in listeners and filters on the console except

i)Value bound
ii)user nto in role

2.The getRemoteUser() isnt returning "max".

The input to form is username:max password:max for authentication as defined in web.xml and the input to Welcom.jsp are max and eassy .
The servlet check if the username and password are same as defined in database and upon correct login forwards request to other JSP

I am using Eclipse Helios and tomcat server 5.5 .
please do tell where to see tomcat logs.

Files are:

web.xml


<?xml version="1.0" encoding="UTF-8"?> <web-app id="WebApp_ID" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"> <display-name>Scwcd</display-name> <login-config> <auth-method>BASIC</auth-method> </login-config> <security-constraint> <web-resource-collection> <web-resource-name>constraint</web-resource-name> <url-pattern>/Welcom.jsp</url-pattern> <http-method>GET</http-method> </web-resource-collection> <auth-constraint> <role-name>max</role-name> </auth-constraint> <user-data-constraint> <transport-guarantee>NONE</transport-guarantee> </user-data-constraint> </security-constraint> <security-role> <role-name>max</role-name> </security-role> <init-param> <param-name>DatabaseName</param-name> <param-value>SCWCD</param-value> </init-param> <listener> <listener-class>listeners.HttpSessionAttributee</listener-class> </listener> <listener> <listener-class>listeners.HttpSesssion</listener-class> </listener> <listener> <listener-class>listeners.ServletAttributee</listener-class> </listener> <listener> <listener-class>listeners.ServletContexxt</listener-class> </listener> <servlet-name>Welcome</servlet-name> <servlet-class>servlets.Sign</servlet-class> </servlet> <servlet> <servlet-name>EngineStatusCheck</servlet-name> <servlet-class>engine.HealthCheck</servlet-class> </servlet> <servlet-mapping> <servlet-name>Welcome</servlet-name> <url-pattern>/SignIn</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>EngineStatusCheck</servlet-name> <url-pattern>/EngineStatusCheck</url-pattern> </servlet-mapping> <filter> <filter-name>Login-Filter</filter-name> <filter-class>filter.LoginFilter</filter-class> </filter> <filter-mapping> <filter-name>Login-Filter</filter-name> <servlet-name>Welcome</servlet-name> </filter-mapping> </web-app>

listeners:

Employee

package listeners;

import javax.servlet.http.HttpSessionBindingEvent;
import javax.servlet.http.HttpSessionBindingListener;

public class Employee implements HttpSessionBindingListener {

	private String name,password;
	
	public Employee(){
		
	}
	
	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}

	
	public void valueBound(HttpSessionBindingEvent arg0) {
	System.out.println("Value Bound");
		
	}

	
	public void valueUnbound(HttpSessionBindingEvent arg0) {
		System.out.println("ValueUnbound");
		
	}

}

HttpSessionAttributeListener

package listeners;

import javax.servlet.http.HttpSessionAttributeListener;
import javax.servlet.http.HttpSessionBindingEvent;

public class HttpSessionAttributee implements HttpSessionAttributeListener {

	
	public void attributeAdded(HttpSessionBindingEvent arg0) {
		System.out.println("HTTPattributeadded  "+"name="+arg0.getName()+",value="+arg0.getValue());
		
	}

	
	public void attributeRemoved(HttpSessionBindingEvent arg0) {
		System.out.println("HttpSattributeadded  "+"name="+arg0.getName()+",value="+arg0.getValue());
		
	}

	
	public void attributeReplaced(HttpSessionBindingEvent arg0) {
		System.out.println("HttpSattributeadded  "+"name="+arg0.getName()+",value="+arg0.getValue());
		
	}

}

HttpSession

package listeners;

import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;

public class HttpSesssion implements HttpSessionListener{

	
	public void sessionCreated(HttpSessionEvent arg0) {
		
		System.out.println("Session Created");
	}

	
	public void sessionDestroyed(HttpSessionEvent arg0) {
		System.out.println("Session Destroyed");
		
	}

}

ServletContexxt

package listeners;

import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

public class ServletContexxt  implements ServletContextListener{

	public void contextInitialized(ServletContextEvent eve){
		System.out.println("Context Created");
		
	}
	public void contextDestroyed(ServletContextEvent eve){
		System.out.println("Context Destroyed");
		
	}

	
}

Servlets:

Sign

package servlets;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Enumeration;
import java.util.Map;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class Sign extends HttpServlet {

	String name, pass;
	Connection con;
	Statement st;
	PreparedStatement pr;
	ResultSet rs;

	public void init() {
		try {
			Class.forName("com.mysql.jdbc.Driver");
		} catch (ClassNotFoundException e) {
			
		}

	}

	public void doGet(HttpServletRequest req, HttpServletResponse resp)
	throws ServletException, IOException {

		try {
			con = DriverManager.getConnection(
					"jdbc:mysql://localhost:3306/SCWCD", "root", "mo");

			name = req.getParameter("username");
			pass = req.getParameter("password");

			
			PrintWriter out = resp.getWriter();
			resp.setContentType("text/html");
			//USer Check
			pr = con.prepareStatement("Select name,password from login where name=? and password=?");
			pr.setString(1, name);
			pr.setString(2, pass);
			rs = pr.executeQuery();

			if (rs.next() == true) {
				
                                //add attribute to seession
				HttpSession ss = req.getSession();
				ss.setAttribute("username", name);
				
                                listeners.Employee emp=new listeners.Employee();
				emp.setName(name);
				emp.setPassword(pass);
                                
                                //add 2nd attribute(emp object) to session 
				ss.setAttribute("empDetails",emp);

				RequestDispatcher rd = getServletContext().getRequestDispatcher("/SignedInUser.jsp");
				rd.forward(req, resp);
			} else {
				
				resp.sendError(405,"as");
				RequestDispatcher rd = req.getRequestDispatcher("Welcome.html");
				rd.include(req, resp);
			}
			
		} catch (SQLException e) {
					}
	}

	public void Destroy() {

	}
}

filters

LoginFilter

package filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;

public class LoginFilter implements Filter  {

	
	private FilterConfig fc;
	
	public void destroy() {
	
		
	}

	
	public void doFilter(ServletRequest req, ServletResponse resp,
			FilterChain chain) throws IOException, ServletException {
	
		HttpServletRequest httpreq=(HttpServletRequest)req;
		String name=httpreq.getRemoteUser(); //ITs returninig null but it should return max as the role is specified in the web.xml
		System.out.println("user in nto filter");
		if(name!=null){
			
			System.out.println("user in filter");
		}
	
		chain.doFilter(req,resp);
	}
	

	
	public void init(FilterConfig config) throws ServletException {
		
		
		this.fc=config;
	}

}

Welcom.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%> <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>Welcome to Production </title> </head> <body> <c:url value="Register.jsp" var="myUrl"> </c:url> <a href='<c:out value="${myUrl}"/>'>Register</a> <form action="SignIn" method="get"> <table> <tr> <tr><td>Username</td> <td><input type="text" name="username"></td> <tr><td>Password</td> <td><input type="text" name="password"></td> <tr> <td></td> <td><input type="submit" value=submit></td> </tr> </table> </form> </body> </html>



Output on Console:

Oct 9, 2011 12:48:40 PM org.apache.catalina.core.AprLifecycleListener init
INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: C:\Program Files\Java\jdk1.6.0_23\bin;.;C:\Windows\Sun\Java\bin;C:\Windows\system32;C:\Windows;C:/Program Files/Java/jre6/bin/client;C:/Program Files/Java/jre6/bin;C:/Program Files/Java/jre6/lib/i386;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files\ATI Technologies\ATI.ACE\Core-Static;C:\Program Files\Java\jdk1.6.0_23\bin;C:\Program Files\Intel\WiFi\bin\;C:\Program Files\Graphviz2.26.3\bin;C:\Program Files\Java\jdk1.6.0_23\bin;C:\TCWIN45\BIN
Oct 9, 2011 12:48:40 PM org.apache.coyote.http11.Http11BaseProtocol init
INFO: Initializing Coyote HTTP/1.1 on http-8080
Oct 9, 2011 12:48:40 PM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 393 ms
Oct 9, 2011 12:48:40 PM org.apache.catalina.core.StandardService start
INFO: Starting service Catalina
Oct 9, 2011 12:48:40 PM org.apache.catalina.core.StandardEngine start
INFO: Starting Servlet Engine: Apache Tomcat/5.5.31
Oct 9, 2011 12:48:40 PM org.apache.catalina.core.StandardHost start
INFO: XML validation disabled
Oct 9, 2011 12:48:41 PM org.apache.coyote.http11.Http11BaseProtocol start
INFO: Starting Coyote HTTP/1.1 on http-8080
Oct 9, 2011 12:48:41 PM org.apache.jk.common.ChannelSocket init
INFO: JK: ajp13 listening on /0.0.0.0:8009
Oct 9, 2011 12:48:41 PM org.apache.jk.server.JkMain start
INFO: Jk running ID=0 time=0/17 config=null
Oct 9, 2011 12:48:41 PM org.apache.catalina.storeconfig.StoreLoader load
INFO: Find registry server-registry.xml at classpath resource
Oct 9, 2011 12:48:41 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 413 ms

user in nto filter
Value Bound

[Niiraj Patel]

Mohit,

Please dont use class names from Servlet API. It creates confusion while reading.

Try to remove other code from your servlet and filter.

Try to include code which is related to this thread only.

So anyone can read it easily.

Please resubmit your code.

Thanks,
Niraj

[Mohit G Gupta]

I have corrected the code Niraj.
Please Help.

[Mohit G Gupta]

Hi fellow ranchers,

Please provide a solution for the problem.

[Frits Walraven]

Hi,

There is a lot of code to digest, also code not relevant to your problem that is why people probably didn't give you an answer immediatly.

First of all, correct the mistakes in your web.xml:
<init-param> <param-name>DatabaseName</param-name> <param-value>SCWCD</param-value> </init-param>should be
<context-param> <param-name>DatabaseName</param-name> <param-value>SCWCD</param-value> </context-param>and <servlet-name>Welcome</servlet-name> <servlet-class>servlets.Sign</servlet-class> </servlet> should be
<servlet> <servlet-name>Welcome</servlet-name> <servlet-class>servlets.Sign</servlet-class> </servlet>
Secondly: I couldnot get it working because of the <user-data-constraint>, did you do anything to the Tomcat settings (like enable SSL-port?)

Thirdly: your Welcom.jsp is protected and once you are in it you have a sort of login-form again: any reason for that? The username and password are not used by the standard JEE security, if you want that you have to use form-login like this:
<html> <head><title>Login Form</title></head> <body> <form action="j_security_check" method="POST"> <br />Name: <input type="text" name="j_username" /> <br />Password: <input type="password" name="j_password" /> <br /><input type="submit" value="Log In" /> </form> </body> </html>
and a web.xml entry like this
<login-config> <auth-method>FORM</auth-method> <form-login-config> <form-login-page>/login.html</form-login-page> <form-error-page>/error.html</form-error-page> </form-login-config> </login-config>
Regards,
Frits

[Mohit G Gupta]

I have made modification to web.xml and LoginFilter.
Still, I am unable to see any of the system.out.println in listeners and filters on the console except

i)Value bound
ii)user nto in role

web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app id="WebApp_ID" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"> <display-name>Scwcd</display-name> <context-param> <param-name>DatabaseName</param-name> <param-value>SCWCD</param-value> </context-param> <listener> <listener-class>listeners.HttpSessionAttributee</listener-class> </listener> <listener> <listener-class>listeners.HttpSesssion</listener-class> </listener> <listener> <listener-class>listeners.ServletAttributee</listener-class> </listener> <listener> <listener-class>listeners.ServletContexxt</listener-class> </listener> <servlet> <servlet-name>Welcome</servlet-name> <servlet-class>servlets.Sign</servlet-class> </servlet> <servlet> <servlet-name>EngineStatusCheck</servlet-name> <servlet-class>engine.HealthCheck</servlet-class> </servlet> <servlet-mapping> <servlet-name>Welcome</servlet-name> <url-pattern>/SignIn</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>EngineStatusCheck</servlet-name> <url-pattern>/EngineStatusCheck</url-pattern> </servlet-mapping> <filter> <filter-name>Login-Filter</filter-name> <filter-class>filter.LoginFilter</filter-class> </filter> <filter-mapping> <filter-name>Login-Filter</filter-name> <servlet-name>Welcome</servlet-name> </filter-mapping> </web-app>
LoginFilter,

package filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;

public class LoginFilter implements Filter  {

	
	private FilterConfig fc;
	
	public void destroy() {
	
		
	}

	
	public void doFilter(ServletRequest req, ServletResponse resp,
			FilterChain chain) throws IOException, ServletException {
	
		HttpServletRequest httpreq=(HttpServletRequest)req;
		
		System.out.println("user in nto filter");
		if(name!=null){
			
			System.out.println("user in filter");
		}
	
		chain.doFilter(req,resp);
	}
	

	
	public void init(FilterConfig config) throws ServletException {
		
		
		this.fc=config;
	}

}

[Frits Walraven]

You didn't answer my question about your login page....

How far did you check the flow of your application? Did you get into your Sign Servlet? If so, add a System.out.println() in the catch statement and see if it gets there.

What do you expect to happen, because you only give code without further explanation?

Regards,
Frits

[Mohit G Gupta]

i added the login page as I was trying different security mechanism for the servlet.
Anyways,Thanks Frits i got the code working.