Spring Boot Security Customize Login and Logout

Details: Written by Nam Ha Minh; Last Updated on 27 April 2020 | Print Email

Spring Security makes it easy to secure webpages in Java web application based on Spring framework. Furthermore, Spring Security APIs are highly flexible, allowing programmers to customize various details of the authentication and authorization process.

Throughout this article, you will learn how to customize login and logout details provided by Spring Security APIs.

1. Customize Login Details

When form login method is used, Spring Security will display the default login page that looks like this:

In case you want to use your own login page, specify URL of the custom login page using this code:

@Override
protected void configure(HttpSecurity http) throws Exception {

	http.formLogin().loginPage("/login");
	...
}

For this you must configure Spring MVC review resolver to map the URL /login with a view name, for example:

package net.codejava;

import org.springframework.context.annotation.*;
import org.springframework.web.servlet.config.annotation.*;

@Configuration
public class MvcConfig implements WebMvcConfigurer {

	@Override
	public void addViewControllers(ViewControllerRegistry registry) {
	
		registry.addViewController("/login").setViewName("login");
		
	}

}

And write code for the customized login page as follows:

<!DOCTYPE html>
<html xmlns:th="http:/www.thymeleaf.org">
<head>
<meta charset="ISO-8859-1">
<title>Login - Company ABC</title>
</head>
<body>
<div>
<form th:action="@{/login}" method="post" style="max-width: 400px; margin: 0 auto;">
	<p>
		E-mail: <input type="email" name="username" required />	
	</p>
	<p>
		Password: <input type="password" name="password" required />
	</p>
	<p>
		<input type="submit" value="Login" />
	</p>
</form>
</div>
</body>
</html>

By default, Spring Security uses the field names username and password, and the action of the form is /login. If you want to use different field names and URL, specify them using Java code as below:

http.formLogin()
	.loginPage("/login")
	.usernameParameter("email")
	.passwordParameter("pass")
	.loginProcessingUrl("/doLogin");

And update code of the login form accordingly:

<form th:action="@{/doLogin}" method="post">
	<p>
		E-mail: <input type="email" name="email" required />	
	</p>
	<p>
		Password: <input type="password" name="pass" required />
	</p>
	<p>
		<input type="submit" value="Login" />
	</p>
</form>

Login Default Success URL:

Spring Security will redirect the users to the page he has visited prior to login. For example, if a user visits the create new product page that requires authentication, he will be redirected to the login page. And after login succeeded, he will be sent back to the create new product page. This is the right logic in case the user visited a secured page before.

In case you want to show user a separate page after he visits an unsecured page prior to login, specify the default success URL as follows:

http.formLogin()
	.defaultSuccessUrl("/login_success");

Remember that the default login success page appears only when the user visited an unsecured page prior to login.

Login Failure URL:

By default, Spring Security will redirects to /login?error if the user failed to login. If you want to change this behavior, e.g. showing your own page that displays login error message to the user – then specify the custom login error page using this code:

http.formLogin()
	.failureUrl("/login_error");

Login Success Forward URL:

If you want to execute some extra code after the user has logged in successfully, e.g. logging or auditing, then specify the success forward URL like this:

http.formLogin()
	.successForwardUrl("/login_success_handler");

For this to work, you must write a corresponding handler method in the controller class. For example:

@Controller
public class AppController {

	@PostMapping("/login_success_handler")
	public String loginSuccessHandler() {
		System.out.println("Logging user login success...");

		return "index";
	}	
}

In this login success handler method, you specify where the user will go after login successfully.

Login Failure Forward URL:

If you want to run some extra code if the user failed to login, specify the failure forward URL like this:

http.formLogin()
	.failureForwardUrl("/login_failure_handler");

And code the handler method in the controller like this:

@PostMapping("/login_failure_handler")
public String loginFailureHandler() {
	System.out.println("Login failure handler....");
	
	return "login";
}

In this login failure handler method, you decide which page which the user should see afterward.

Login Success Handler:

Similar to login success forward URL, you can also write an authentication success handler as follows:

http.formLogin()
.successHandler(new AuthenticationSuccessHandler() {
	
	@Override
	public void onAuthenticationSuccess(HttpServletRequest request, HttpServletResponse response,
			Authentication authentication) throws IOException, ServletException {
		
		System.out.println("Logged user: " + authentication.getName());
		
		response.sendRedirect("/");
	}
});

This gives you greater control as you can access an Authentication object directly.

Login Failure Handler:

Instead of using login failure forward URL, you can use an authentication failure handler as follows:

http.formLogin()
.failureHandler(new AuthenticationFailureHandler() {
	
	@Override
	public void onAuthenticationFailure(HttpServletRequest request, HttpServletResponse response,
			AuthenticationException exception) throws IOException, ServletException {
		System.out.println("Login failed");
		System.out.println(exception);
		
		response.sendRedirect("/login_error");
	}
});

This gives you greater control as you can access an AuthenticationException object directly.

2. Customize Logout Details

Besides login customization, Spring Security also allows programmers to customize the logout process. Basically you code the Logout button like this:

<form th:action="@{/logout}" method="post">
	<input type="submit" value="Logout" />
</form>

The first thing you can change is the logout URL.

Logout URL:

By default, Spring Security processes the /logout URL via HTTP POST method. You can configure the HttpSecurity object to change this URL as below:

http.logout()
	.logoutUrl("/doLogout");

For this to work, you must update action URL of the logout form accordingly:

<form th:action="@{/doLogout}" method="post">

Logout Success URL:

By default, the user will see the login page after logging out of the application. If you want to show a customized page to the user, specify the logout success URL as follows:

http.logout()
	.logoutSuccessUrl("/logout_success");

Logout Success Handler:

If you want to perform extra steps after the user logged out successfully, use a logout success hander like this:

http.logout()
.logoutSuccessHandler(new LogoutSuccessHandler() {
	
	@Override
	public void onLogoutSuccess(HttpServletRequest request, HttpServletResponse response, 
				Authentication authentication)
			throws IOException, ServletException {
		
		System.out.println("This user logged out: " + authentication.getName());
		
		response.sendRedirect("/logout_success");
	}
});

Use Logout link instead of button:

The reason you should use Logout button because Spring Security automatically generates a security token to prevent CSRF (Cross-Site Request Forgery) attack in the login page. For example:

<input type="hidden" name="_csrf" value="8ec12704-5ab6-4f0c-a758-2fc36f2c9368"/>

That’s why the logout request must be sent via HTTP POST method. You can disable CSRF prevention to use a logout link (via HTTP GET method) using this code:

http.csrf().disable();

However, this is not recommended for applications that go on production. So the best way is to hide the logout form and use Javascript for the logout link, as shown in the following example:

<form name="logoutForm" th:hidden="true" method="post" th:action="@{/doLogout}">
	<input type="submit" value="Logout" />
</form>
<a href="javascript: logoutForm.submit();">Sign Out</a>

That’s how to customize login and logout details for a Java web application built on Spring Boot. As you have seen, Spring Security provides highly flexible and customizable APIs so you can use with ease.

I recommend you to watch this video for the visual howtos:

About the Author:

Nam Ha Minh is certified Java programmer (SCJP and SCWCD). He started programming with Java in the time of Java 1.4 and has been falling in love with Java since then. Make friend with him on Facebook and watch his Java videos you YouTube.