Custom Error Message in Spring Security Application

In the previous topic, we have learned to use a custom login page in Spring Security rather than the framework's built-in login page. With this login page, we had no concept of showing an error message if the user passes the wrong credentials. Now, we will create a login page that will show an error message.

To implement this feature, Spring provides a JSTL core library that helps to write Expression Language. Put the below code at the top of the login page.

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>

After adding the above line to the JSP page, use the below code that will show an error message if the error parameter is attached to the URL. If the user enters the wrong credentials then Spring Security responds by attaching an error parameter to the URL.

<c:if test="${param.error!=null}">
    <p style="color: red">You entered wrong credentials!</p>
</c:if>

Project Source Code

The following are the files of the project. You can use these in your project to test the application.

// AppConfig.java

This is our application configuration file that implements WebMvcConfugurer interface to make this MVC application and created a method viewResolver to map our views files(JSP).

package com.studytonight;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.view.InternalResourceViewResolver;

@EnableWebMvc
@Configuration
@ComponentScan("com.studytonight.controller")
public class AppConfig implements WebMvcConfigurer{
	@Bean
	public ViewResolver viewResolver() {
		InternalResourceViewResolver irvr = new InternalResourceViewResolver();
		irvr.setPrefix("WEB-INF/views/");
		irvr.setSuffix(".jsp");
		irvr.setOrder(0);
		return irvr;
	}
}

// MainApp.java

This class initialize our web application and creates ServletContext by using that we register our AppConfig class(above file).

package com.studytonight;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRegistration;
import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.servlet.DispatcherServlet;
public class MainApp implements WebApplicationInitializer {

	@Override
	public void onStartup(ServletContext servletContext) throws ServletException {
		System.out.println("started");
		AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
		context.register(AppConfig.class);
		context.setServletContext(servletContext);
		ServletRegistration.Dynamic servlet = servletContext.addServlet("dispatcher", new DispatcherServlet(context));
		servlet.setLoadOnStartup(1);
		servlet.addMapping("/");
		context.close();	
	}
}

// SecurityAppInitializer.java

This is the Security initializer class that extends AbstractSecurityWebApplicationInitializer and we passed our SecurityConfig class so that it can read security configurations.

package com.studytonight;

import org.springframework.security.web.context.AbstractSecurityWebApplicationInitializer;
public class SecurityAppInitializer  extends AbstractSecurityWebApplicationInitializer {

	public SecurityAppInitializer() {
		super(SecurityConfig.class);
	}
}

// SecurityConfig.java

This is our security configuration file that extends WebSecurityConfigurerAdapter class and provides several methods such as configure() to configure the security. Spring Security provides AuthenticationManagerBuilder class that works as an Authentication Manager and provides several methods to authenticate the user. Here, we are using inMemoryAuthentication concept that allows mapping hard-coded user values.

We used HttpSecurity class to configure the login page. The loginPage() method is used to specify our login.jsp page. We can also use any other name for the login form such as login-form.jsp or user-login.jsp and then specify the mapping to this method. The "/login" value passed here will map to the controller's action and then render the JSP page.

package com.studytonight;

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;
import org.springframework.security.core.userdetails.User;
import org.springframework.security.core.userdetails.User.UserBuilder;

@Configuration
@EnableWebSecurity	
public class SecurityConfig extends WebSecurityConfigurerAdapter{

	@Override
	protected void configure(AuthenticationManagerBuilder auth) throws Exception {

		UserBuilder users = User.withDefaultPasswordEncoder();		
		auth.inMemoryAuthentication()
			.withUser(users.username("studytonight").password("abc123").roles("admin"));
	}
	
	@Autowired
	protected void configure(HttpSecurity hs) throws Exception {
		hs.authorizeRequests().anyRequest()
		.authenticated()
		.and()
		.formLogin()
		.loginPage("/login")
		.loginProcessingUrl("/authenticateTheUser")
		.permitAll();
	}
}

// UserController.java

This is our controller class that works as a user request handler and maps user requests with the resources and returns responses accordingly. We created the login() method to render the login page and the home() method to show the index.jsp page and course() method to display course.jsp page.

package com.studytonight.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;

@Controller
public class UserController {

	@GetMapping("/login")
	public String login() {
		return "login";
	}
	
	@GetMapping("/")  
	public String home() {
		return "index";
	}

	@GetMapping("/java-course")
	public String course() {
		return "course";
	}

	@GetMapping("/premium-courses")
	public String premiumCourse() {
		return "premium-courses";
	}
}

View Files

These are views files of our project that displayed to the browser. See the code.

// premium courses.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Course Page</title>
</head>
<body>
	<h2>List of Premium Courses</h2>
	<ul>
		<li>Spring Framework</li>
		<li>Pandas</li>
		<li>Spring Security</li>
	</ul>
</body>
</html>

// course.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Course Page</title>
</head>
<body>
	<h2>List of Courses</h2>
	<ul>
		<li>Java</li>
		<li>Python</li>
		<li>C++</li>
		<li>Linux</li>
	</ul>
</body>
</html>

// index.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Home Page</title>
</head>
<body>
	<h2>Welcome to Studytonight!</h2>
	<h3><a href="java-course">Study Java</a></h3>
	<h2><a href="premium-courses">Study Premium Courses</a></h2>
</body>
</html>

// pom.xml

This file contains all the dependencies of this project such as spring jars, servlet jars, etc. Put these dependencies into your project to run the application.

<project xmlns="http://maven.apache.org/POM/4.0.0"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>com.studytonight</groupId>
	<artifactId>springwithsecurity</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>war</packaging>
	<properties>
		<spring.version>5.2.8.RELEASE</spring.version>
	</properties>
	<dependencies>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-core</artifactId>
			<version>${spring.version}</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-context</artifactId>
			<version>${spring.version}</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-webmvc</artifactId>
			<version>${spring.version}</version>
		</dependency>
		<!-- https://mvnrepository.com/artifact/javax.servlet/servlet-api -->
		<!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
		<dependency>
			<groupId>javax.servlet</groupId>
			<artifactId>javax.servlet-api</artifactId>
			<version>4.0.1</version>
		</dependency>
		<!-- https://mvnrepository.com/artifact/jstl/jstl -->
        <dependency>
            <groupId>jstl</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>

		<!-- https://mvnrepository.com/artifact/javax.servlet.jsp/javax.servlet.jsp-api -->
		<dependency>
			<groupId>javax.servlet.jsp</groupId>
			<artifactId>javax.servlet.jsp-api</artifactId>
			<version>2.3.3</version>
		</dependency>
		<!-- https://mvnrepository.com/artifact/javax.servlet.jsp.jstl/jstl-api -->
		<dependency>
			<groupId>javax.servlet.jsp.jstl</groupId>
			<artifactId>jstl-api</artifactId>
			<version>1.2</version>
		</dependency>


		<!-- https://mvnrepository.com/artifact/javax.xml.bind/jaxb-api -->
		<dependency>
			<groupId>javax.xml.bind</groupId>
			<artifactId>jaxb-api</artifactId>
			<version>2.3.0</version>
		</dependency>
		<!-- https://mvnrepository.com/artifact/org.springframework.security/spring-security-web -->
		<dependency>
			<groupId>org.springframework.security</groupId>
			<artifactId>spring-security-web</artifactId>
			<version>5.4.2</version>
		</dependency>
		<!-- https://mvnrepository.com/artifact/org.springframework.security/spring-security-config -->
		<dependency>
			<groupId>org.springframework.security</groupId>
			<artifactId>spring-security-config</artifactId>
			<version>5.4.2</version>
		</dependency>
	</dependencies>
	<build>
		<plugins>
			<plugin>
				<artifactId>maven-war-plugin</artifactId>
				<version>3.2.3</version>
				<configuration>
					<warSourceDirectory>WebContent</warSourceDirectory>
				</configuration>
			</plugin>
			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-compiler-plugin</artifactId>
				<version>3.5.1</version>
				<configuration>
					<source>11</source>
					<target>11</target>
				</configuration>
			</plugin>
		</plugins>
	</build>
</project>

Project Structure

After creating these files our project will look like the below. You can refer to this to understand the directory structure of the project.

Run the Application

After successfully completing the project and adding the dependencies run the application and you will get the output as below.

Note: In our application, we created a login.jsp page and configured with the Spring Security. Now, when we run the application it renders a login page which is our own page.

It will match the username and password with the credentials provided in the SecurityConfig.java file.

Provide the Wrong Username and Passwords