Introduction🤔
When dealing with the struts2 application, you might need to access the HTTP session object. Your action class should implement the SessionAware interface provided by struts 2 to obtain a reference to the HTTP session object.
So let us learn about the SessionAware interface.😊
SessionAware Interface🎯
This interface should be implemented by actions that want access to the user's HTTP session attributes. Implementing this interface will give actions access to a map where they can put objects which can be made available to subsequent requests.
Method
void setSession(Map<String,Object> session
Description
The SessionMap class instance is passed when the struts framework calls this method.
SessionAware interface example🧑🏫
In this example, we will make a JSP page with three links for the user. From there, the user will be redirected to various pages depending upon action on various links.
First, set up the basic struts web application and name it sessionaware_interface.
Step1🧑💻 - Create a JSP page and name it as index.jsp
index.jsp
<!DOCTYPE html>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<body>
<h1>Struts2 SessionAware Interface Example</h1>
<ul>
<li><a href="loginpage">LogIn</a></li>
<li><a href="userlogout">LogOut</a></li>
<li><a href="userprofile">UserProfile</a> </li>
</ul>
</body>
</html>
Step2⭐ - Handle various actions of the user and corresponding responses in struts.xml
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.devMode" value="true"></constant>
<package name="com.sessionaware_interface" extends="struts-default" >
<action name="loginpage">
<result>login.jsp</result>
</action>
<action name="userlogin" class="com.sessionaware_interface.Login" method="execute">
<result name="success">/login-success.jsp</result>
<result name="userlogin">/login-error.jsp</result>
</action>
<action name="userlogout" class="com.sessionaware_interface.Login" method="userlogout">
<result name="success">/logout-success.jsp</result>
</action>
<action name="userprofile" class="com.sessionaware_interface.Profile" method="execute">
<result name="success">/profile-success.jsp</result>
<result name="userlogin">/profile-error.jsp</result>
</action>
</package>
</struts>
Step3✨ - Create the action class for login and logout, implement SessionAware Interface and to store the information in the session scope override setSession.
inout.java
package com.sessionaware_interface;
import java.util.Map;
import org.apache.struts2.dispatcher.SessionMap;
import org.apache.struts2.interceptor.SessionAware;
public class Login implements SessionAware{
private String name,password;
private SessionMap<String,Object> sessionMap;
@Override
public void setSession(Map<String, Object> map) {
sessionMap=(SessionMap)map;
}
public String execute(){
if(password.equals("admin")){
sessionMap.put("userlogin","true");
sessionMap.put("username",name);
return "success";
}
else{
return "userlogin";
}
}
public String logout(){
if(sessionMap!=null){
sessionMap.invalidate();
}
return "success";
}
}
Step4✨ - Create the profile class to fetch information from the session scope.
profile.java
package com.sessionaware_interface;
import javax.servlet.http.HttpSession;
import org.apache.struts2.ServletActionContext;
public class Profile{
public String execute(){
HttpSession session=ServletActionContext.getRequest().getSession(false);
if(session==null || session.getAttribute("userlogin")==null){ return "userlogin";
}
else{
return "success";
}
}
}
Step5🧑🎨 - Create the following JSP pages[View Components].
- login.jsp - for the login page.
- login-success.jsp - to show the welcome message with username after login.
- login-error.jsp - to show an error message while logging.
- logout-success.jsp - to show message after logout.
- profile-success.jsp - to show the welcome message on the profile page.
- profile-error.jsp - to show the error message if the user tries to visit the profile page without inputting credentials.
login.jsp
<!DOCTYPE html>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<body>
<s:form action="userlogin">
<s:textfield name="username" label="UserName"></s:textfield>
<s:password name="password" label="Password"></s:password>
<s:submit value="userlogin"></s:submit>
</s:form>
</body>
</html>
login-success.jsp
<!DOCTYPE html>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<body>
<jsp:include page="index.jsp"></jsp:include>
<hr>
Welcome, Ninja - <s:property value="#session.name"/>
</body>
</html>
login-error.jsp
<!DOCTYPE html>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<body>
<jsp:include page="index.jsp"></jsp:include>
<hr>
Sorry Ninja, username/password Error!
<jsp:include page="login.jsp"></jsp:include>
</body>
</html>
logout-success.jsp
<!DOCTYPE html>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<body>
<jsp:include page="index.jsp"></jsp:include>
<hr>
Ninja, you are successfully logged out!
</body>
</html>
profile-success.jsp
<!DOCTYPE html>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<body>
<jsp:include page="index.jsp"></jsp:include>
<hr>
Welcome to Profile, Ninja - <s:property value="#session.name"/>
</body>
</html>
profile-error.jsp
<!DOCTYPE html>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<body>
<jsp:include page="index.jsp"></jsp:include>
<hr>
Sorry Ninja, username/password Error!
<jsp:include page="login.jsp"></jsp:include>
</body>
</html>
Step6🕸 - Make changes to the web.xml file.
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_2_5.xsd"
id="WebApp_ID" version="2.5">
<display-name>sessionaware_interface</display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<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>
</web-app>
Step7 - Execution🦾
Start the server and hit the given below URL
URL👉 - http://localhost:8080/sessionaware_interface/
Response💫 -
Now click on the UserProfile you will get redirected to URL
👉 - http://localhost:8080/sessionaware_interface/profile
Response💫 -
Input username and password -
Click on the Login you will get redirected to URL
👉 - http://localhost:8080/sessionaware_interface/login
Response💫 -
Click on the UserProfile you will get redirected to URL
👉 - http://localhost:8080/sessionaware_interface/profile
Response💫 -
Click on the LogOut you will get redirected to URL
👉 - http://localhost:8080/sessionaware_interface/logout
Response💫 -
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