I am new to
struts 2.0 interceptor when user login and successfully validate he goes to a new Page but when he copies the url and enter in some new browser for directly accessing the welcome page it must redirect to login page but it give null pointer exception please help it really urgent thanks in advance
My web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_9" 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>Struts2 Application</display-name>
<filter>
<filter-name>struts2</filter-name>
<filter-class>
org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter
</filter-class>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<welcome-file-list>
<welcome-file>Login.jsp</welcome-file>
</welcome-file-list>
</web-app>
AuthInterceptor.java
package net.aditya.struts2;
import java.util.Map;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.Interceptor;
public class AuthInterceptor implements Interceptor {
@Override
public void destroy() {
// TODO Auto-generated method stub
}
@Override
public void init() {
// TODO Auto-generated method stub
}
@Override
public
String intercept(ActionInvocation invocation) throws Exception {
Map<String,Object> sessionAttribute=invocation.getInvocationContext().getSession();
if(sessionAttribute==null||sessionAttribute.get("authorized")==null)
{
return "failure";
}
else{
if(((String)sessionAttribute.get("authorized")).equals("yes"))
{
return invocation.invoke();
}
else
return "failure";//go to interceptor failure
}
}
}
struts.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<constant name="struts.ui.theme" value="simple" />
<constant name="struts.custom.i18n.resources" value="ApplicationResources" />
<package name="anyUnigueName" extends="struts-default" >
<interceptors>
<interceptor name="authInterceptor" class="net.aditya.struts2.AuthInterceptor">
</interceptor>
<interceptor-stack name="MyInterceptor"> <!-- so that all interceptor like validation work properly -->
<interceptor-ref name="defaultStack" />
<interceptor-ref name="authInterceptor" /> <!-- add custom interceptor -->
</interceptor-stack>
</interceptors>
<action name="login">
<result >/Login.jsp</result>
</action>
<action name="authorized" class="net.aditya.struts2.LoginAction" method="loginCredentialCheck"><!-- if you not provide method name then by default execute is call -->
<result name="success" type="chain">authorizedOnly</result>
<result name="failure">/Login.jsp</result>
<result name="input">/Login.jsp</result>
</action>
<action name="authorizedOnly" >
<interceptor-ref name="MyInterceptor"/>
<result name="success" >/Welcome.jsp</result>
<result name="failure">/Login.jsp</result>
</action>
</package>
</struts>
LoginAction.java
package net.aditya.struts2;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import org.apache.struts2.ServletActionContext;
import businessService.Login;
import com.opensymphony.xwork2.ActionSupport;
public class LoginAction extends ActionSupport{//Action Support is for addActionError msg
private String username;
private String password;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String loginCredentialCheck() {
Login obj=new Login();
String b=obj.compare(getUsername(),getPassword());//method call
if(b.equals("match"))
{ HttpServletRequest request = ServletActionContext.getRequest();
HttpSession session=request.getSession();
session.setAttribute("authorized", "yes");
return "success";
}
else
{
addActionError("Please provide right Credentials");// you can directly put
ant string msg here
return "failure";
}
}
public void validate() {
if (getUsername().length() == 0) {
addFieldError("username", "User Name is required");
}
else if (getPassword().length() == 0) {
addFieldError("password", getText("password.required"));
}
}
}
Login.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<%@ taglib prefix="s" uri="/struts-tags"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<s:actionerror/>
<s:form action="authorized" method="post" >
<table align="center" bgcolor="red" width="80%">
<tr>
<th align="center">Login Form</th>
</tr>
<tr>
<td>Username</td>
<td><s:textfield name="username" /></td>
<td><s:fielderror fieldName="username" /> </td>
</tr>
<tr>
<td>Password</td>
<td><s:password name="password" /></td>
<td><s:fielderror fieldName="password" /> </td>
</tr>
<tr>
<td><s:submit label="Submit" align="center"/></td>
<td><a href="registration.jsp">create Account</a></td>
</tr>
</table>
</s:form>
</body>
</html>
Please Help
