Spring Security 4 Logout Example

This post shows you how to programatically logout a user in Spring Security. This works well with browser back button too. Let’s get going.

SpringSecurityCustomLogoutExample_img4


Generally, In your views, you should be providing a simple logout link to logout a user, something like shown below:

<%@ 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>Admin page</title>
</head>
<body>
	Dear <strong>${user}</strong>, Welcome to Admin Page.
	<a href="<c:url value="/logout" />">Logout</a>
</body>
</html>

Nothing fancy about it. Now , We just need to map this /logout link in our controller. Create a new method like shown below:

	@RequestMapping(value="/logout", method = RequestMethod.GET)
	public String logoutPage (HttpServletRequest request, HttpServletResponse response) {
		Authentication auth = SecurityContextHolder.getContext().getAuthentication();
		if (auth != null){    
			new SecurityContextLogoutHandler().logout(request, response, auth);
		}
		return "redirect:/login?logout";//You can redirect wherever you want, but generally it's a good practice to show login screen again.
	}

Here firstly we identified if user was authenticated before using SecurityContextHolder.getContext().getAuthentication(). If he/she was, then we called SecurityContextLogoutHandler().logout(request, response, auth) to logout user properly.

This logout call performs following:

  • Invalidates HTTP Session ,then unbinds any objects bound to it.
  • Removes the Authentication from the SecurityContext to prevent issues with concurrent requests.
  • Explicitly clears the context value from the current thread.

That’s it. You don’t need anything else anywhere in your application to handle logout. Notice that you don’t even need to do anything special in your spring configuration(xml or annotation based), shown below just for information:

package com.websystique.springsecurity.configuration;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;

@Configuration
@EnableWebSecurity
public class SecurityConfiguration extends WebSecurityConfigurerAdapter {

	
	@Autowired
	public void configureGlobalSecurity(AuthenticationManagerBuilder auth) throws Exception {
		auth.inMemoryAuthentication().withUser("bill").password("abc123").roles("USER");
		auth.inMemoryAuthentication().withUser("admin").password("root123").roles("ADMIN");
		auth.inMemoryAuthentication().withUser("dba").password("root123").roles("ADMIN","DBA");
	}
	
	@Override
	protected void configure(HttpSecurity http) throws Exception {
	  
	  http.authorizeRequests()
	  	.antMatchers("/", "/home").permitAll()
	  	.antMatchers("/admin/**").access("hasRole('ADMIN')")
	  	.antMatchers("/db/**").access("hasRole('ADMIN') and hasRole('DBA')")
	  	.and().formLogin().loginPage("/login")
	  	.usernameParameter("ssoId").passwordParameter("password")
	  	.and().exceptionHandling().accessDeniedPage("/Access_Denied");
	}
}

There is no special logout handling mentioned in above configuration.

Above security configuration in XML configuration format would be:

<beans:beans xmlns="http://www.springframework.org/schema/security"
    xmlns:beans="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
    http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-4.0.xsd">
     
    <http auto-config="true" >
        <intercept-url pattern="/" access="hasRole('USER')" />
        <intercept-url pattern="/home" access="hasRole('USER')" />
        <intercept-url pattern="/admin**" access="hasRole('ADMIN')" />
        <intercept-url pattern="/dba**" access="hasRole('ADMIN') and hasRole('DBA')" />
        <form-login  login-page="/login" 
                     username-parameter="ssoId" 
                     password-parameter="password" 
                     authentication-failure-url="/Access_Denied" />
    </http>
 
    <authentication-manager >
        <authentication-provider>
            <user-service>
                <user name="bill"  password="abc123"  authorities="ROLE_USER" />
                <user name="admin" password="root123" authorities="ROLE_ADMIN" />
                <user name="dba"   password="root123" authorities="ROLE_ADMIN,ROLE_DBA" />
            </user-service>
        </authentication-provider>
    </authentication-manager>
    
</beans:beans>

Rest of application code is same as mentioned in every post in this series. This Post (and actually every post in this series) shows this logout in action.

Deploy & Run

Download complete code of this project using download button shown at the bottom of this post. Build and deploy it on Servlet 3.0 container(Tomcat7/8).

Open your browser, go to http://localhost:8080/SpringSecurityCustomLogoutExample/, home page will be shown

SpringSecurityCustomLogoutExample_img1

Now go to http://localhost:8080/SpringSecurityCustomLogoutExample/admin, you will be prompted for login

SpringSecurityCustomLogoutExample_img2

provide credentials, submit, you will see admin page.

SpringSecurityCustomLogoutExample_img3

click on logout, you will be taken to login page.

SpringSecurityCustomLogoutExample_img4

click on browser back button, you will remain at login screen.

SpringSecurityCustomLogoutExample_img5

That’s it. Next post shows you how to show/hide parts of jsp/view based on logged-in user’s roles, using Spring Security tags.

Download Source Code


References

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