How To Implement Security In Spring Boot Using UserDetailsService?

SpringSecurity_RoleBased_UserDetailsService In continuation to previous article on two different ways of implementing Spring Security, here in this article we will learn the third way ‘How to implement Security in Spring Boot using UserDetailsService?’. After going through the previous article, I hope we all are very familiar with basics of Security and even the basics of Security in a Spring Boot application. This time we will create a user registration form and save users with their roles into database. Then, based on the user role, we will check the authentication and authorization functionalities with the help of predefined UserDetailsService.

To illustrate, we will take some roles into effect and play around them in the whole process to make it crystal clear. Additionally, we will have some pages and restrict them to be accessible by some specific roles only. Equally important, we will have to create a small MVC web application to make registration process open for users. Users will enter their roles while doing registration. Then we can implement security features on top of it. Let’s start working on our topic ‘How to implement Security in Spring Boot using UserDetailsService?’ accordingly.

Table of Contents (Click on links below to navigate)

1 What can you expect from this article on the whole?
2 What is UserDetailsService all about ? What is the benefit of using it?
3 How to implement UserDetailsService Security in our application ?
4 How does UserDetailsService internally work in Spring Security application ?
5 Example of implementing UserDetailsService
6 How to test the security enabled Application ?
7 Summary

What can you expect from this article on the whole?

1) What is an UserDetailsService concept in the context of Spring Security?

2) What is the benefits of implementing UserDetailsService ?

3) How to implement Security in Spring Boot using UserDetailsService ?

4) How does UserDetailsService internally work in Spring Security application with flow diagram ?

5) Moreover, how to use annotations :@EnableWebSecurity, @Configuration, @Bean, @GetMapping, @Autowired, @Data, @Entity, @Table, @Id, @GeneratedValue, @Column, @ElementCollection, @CollectionTable, @JoinColumn, @Service

6) How to develop a user registration app using Spring MVC with Thymeleaf ?

7) How to test the Security enabled application ?

What is UserDetailsService all about ? What is the benefit of using it?

UserDetailsService is a predefined interface exists under package org.springframework.security.core.userdetails in Spring. Our implementation class implements this interface and overrides it’s loadUserByUsername(String username) method. This method returns UserDetails which is again an interface. Predefined User class (org.springframework.security.core.userdetails.User) is an implementation of UserDetails interface. In summary, in loadUserByUsername(String username) method we pass our username and it returns us predefined User object(org.springframework.security.core.userdetails.User).

In fact, we provide only username to UserDetailsService and some small configurations and we get all role based security functionality implemented as part of the framework. Accordingly, we save a lot of effort in implementing security.

How to implement UserDetailsService Security in our application ?

First of all, you must have a Spring Boot web application where in you will have a form i.e. a kind of User registration form. As part of the Spring MVC structure you will have a UserService implementation class. Let’s say it UserServiceImpl.java. The second thing to remember is that you have to convert your User object into predefined Spring’s User object. Further, please follow below steps to get UserDetailsService implemented in your application.

1) Your user service class ‘UserServiceImpl.java’ should implement interface UserDetailsService.java(Provided by Spring)

2) Equally important, Override loadUserByUsername(String username) method of interface UserDetailsService in your UserServiceImpl class.

3) As part of implementation,

(A) Get your User Object with the help of username/email from UserRepository.
(B) Convert your User Object into Spring’s predefined User object(org.springframework.security.core.userdetails.User) accordingly.
(C) Return Spring defined User object which is an implementation of UserDetails(method’s return type).

Below code represents the implementation of UserDetailsService. However, you will see the complete code in below sections consequently.

UserServiceImpl.java

@Service
public class UserServiceImpl implements IUserService, UserDetailsService{
	
	@Autowired
	private UserRepository userRepo;
	
	@Override
	public UserDetails loadUserByUsername(String email) throws UsernameNotFoundException {

		Optional<User> opt = userRepo.findUserByEmail(email);
		
		org.springframework.security.core.userdetails.User springUser=null;
		
		if(opt.isEmpty()) {
			throw new UsernameNotFoundException("User with email: " +email +" not found");
		}else {
			User user =opt.get();
			
			List<String> roles = user.getRoles();
			Set<GrantedAuthority> ga = new HashSet<>();
			for(String role:roles) {
				ga.add(new SimpleGrantedAuthority(role));
			}
			
			springUser = new org.springframework.security.core.userdetails.User(
							email,
							user.getPassword(),
							ga );
							
		}
		
		return springUser;
	}
	
}

How does UserDetailsService internally work in Spring Security application ?

How to implement UserDetailsService

As soon as the user enters username & password and click on the Login button, WebSecurityConfigurerAdapter is called which internally calls UserServiceImpl.java (Implementation class, provided by the programmer). Furthermore, loadUserByUserName( ) method implemented in UserServiceImpl.java converts our User Object into Spring provided User object. Also, our SecurityConfig.java extends WebSecurityConfigurerAdapter and provides an implementation of authentication & authorization logics in two methods; configure(AuthenticationManagerBuilder) & configure(HttpSecurity) respectively as shown in below code.

SecurityConfig.java

@EnableWebSecurity
@Configuration
public class SecurityConfig extends WebSecurityConfigurerAdapter {
	
	@Autowired
	private UserDetailsService uds;
	
	@Autowired
	private BCryptPasswordEncoder encoder;

	@Override
	protected void configure(AuthenticationManagerBuilder auth) throws Exception {
		
		auth.userDetailsService(uds).passwordEncoder(encoder);
	}
	
	@Override
	protected void configure(HttpSecurity http) throws Exception {
		
		http.authorizeRequests()
		.antMatchers("/home","/register","/saveUser").permitAll()
		.antMatchers("/welcome").authenticated()
		.antMatchers("/admin").hasAuthority("Admin")
		.antMatchers("/mgr").hasAuthority("Manager")
		.antMatchers("/emp").hasAuthority("Employee")
		.antMatchers("/hr").hasAuthority("HR")
		.antMatchers("/common").hasAnyAuthority("Employeee,Manager,Admin")
		.anyRequest().authenticated()
		
		.and()
		.formLogin()
		.defaultSuccessUrl("/welcome",true)
		
		.and()
		.logout()
		.logoutRequestMatcher(new AntPathRequestMatcher("/logout"))
		
		.and()
		.exceptionHandling()
		.accessDeniedPage("/accessDenied");
		
	}
}

Note: Spring Security 5.7.0-M2 onward, WebSecurityConfigurerAdapter has been deprecated. In order to learn the new way of implementing custom configuration class, visit a separate article on Spring Security without WebSecurityConfigurerAdapter.

Example of implementing UserDetailsService

To illustrate the implementation of UserDetailsService, let’s assume an internal portal of a small company. In company we have various roles within employees such as Admin, HR, Manager and of course Employee as well. Additionally, the Portal has role based access to pages. Even Some pages are accessible to all roles while others are restricted to some particular roles.

Equally important, the company will have a user registration page which must be accessible to all users, even without login. Now let’s create a standard user registration flow as given below.

How to implement Security in Spring Boot using UserDetailsService?

What Software/Technologies would you need?

♦STS (Spring Tool Suite) : Version-> 4.7.1.RELEASE
⇒Dependent Starters : Spring Security, Thymeleaf, Spring Web, Lombok, Spring Data JPA, MySQL Driver, Spring Boot DevTools
♦MySQL Database : Version ->8.0.19 MySQL Community Server
♦JDK8 or later versions (Extremely tested on JDK8, JDK11 and JDK14)

Let’s follow below steps to develop a small web application and then apply UserDetailsService security into it.

Step#1 : Create a Spring Boot Starter Project in STS(Spring Tool Suite)

While creating Starter Project select ‘Spring Security’, ‘Thymeleaf’, ‘Spring Web’, ‘Spring Data JPA’, ‘MySQL Driver’, ‘Lombok’ and ‘Spring Boot DevTools’ as starter project dependencies. Even If you don’t know how to create a Spring Boot Starter Project, Kindly visit Internal Link. Also, if you want to know more about Lombok, then visit Internal Link on Lombok.

Step#2 : Update database properties in application.properties file

Update application.properties to connect to MySQL DB accordingly. Please note that we can omit driver-class-name as Spring Boot will automatically find it from the database URL as shown below.

#application.properties
---------------------------------------------------------------------
#-------------------- server properties ---------------
server.port=8080

#--------------------- DB Connection ------------------
#AutoLoading of driver class since JDBC 4
#spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver 
spring.datasource.url=jdbc:mysql://localhost:3306/testBootSecurity
spring.datasource.username=root
spring.datasource.password=devs

#--------------------JPA-ORM Properties-----------------
spring.jpa.show-sql=true
spring.jpa.hibernate.ddl-auto=update
#spring.jpa.database-platform=org.hibernet.dialect.MySQL8Dialect

Step#3 : Create User Entity & Repository classes

Now create User.java & UserRepositoty.java as below. Equally important, User.java has a variable ‘roles’ of type List<String>. It will create a separate table in the database with two columns user_id and user_role accordingly. Further, @ElementCollection(fetch= FetchType.EAGER) indicates that while fetching User object, also fetch roles simultaneously. On the other hand, UserRepository extends ‘JpaRepository’ to taking advantage of inbuilt database operations.

User.java

package com.dev.springboot.security.UserDetailsService.model;

import java.util.List;

import javax.persistence.CollectionTable;
import javax.persistence.Column;
import javax.persistence.ElementCollection;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.Table;

import lombok.Data;

@Data
@Entity
@Table(name="users")
public class User {
	
	@Id
	@GeneratedValue
	@Column(name="user_id")
	private Integer id;
	
	@Column(name="user_name")
	private String name;
	
	@Column(name="user_passwd")
	private String password;
	
	@Column(name="user_email")
	private String email;
	
	@ElementCollection(fetch= FetchType.EAGER)
	@CollectionTable(
			name="roles",
			joinColumns = @JoinColumn(name="user_id")
			)
	@Column(name="user_role")
	private List<String> roles;
	
}

UserRepository.java

package com.dev.springboot.security.UserDetailsService.repo;

import java.util.Optional;

import org.springframework.data.jpa.repository.JpaRepository;

import com.dev.springboot.security.UserDetailsService.model.User;

public interface UserRepository extends JpaRepository<User, Integer> {

	Optional<User> findUserByEmail(String email);
}

Step#4 : Create AppConfig class to instantiate BCryptPasswordEncoder

As BCryptPasswordEncoder is a predefined class, hence we need to provide it’s instantiation code in AppConfig.java as a configuration class. Further, BCryptPasswordEncoder will be required to encode our password values in other classes.

AppConfig.java

package com.dev.springboot.security.UserDetailsService.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;

@Configuration
public class AppConfig {

	@Bean
	public BCryptPasswordEncoder passwordEncoder() {
		return new BCryptPasswordEncoder();
	}
}

Step#5 : Create Service Interface & Service Implementation class

Create Service Interface and Service Impl class as IUserService.java and UserServiceImpl.java accordingly as shown below. In fact, implementation of loadUserByUsername(String email) method in UserServiceImpl.java is the most important part of your UserDetailsService on the whole.

IUserService.java

package com.dev.springboot.security.UserDetailsService.service;

import com.dev.springboot.security.UserDetailsService.model.User;

public interface IUserService {
	
	public Integer saveUser(User user);
}

UserServiceImpl.java

package com.dev.springboot.security.UserDetailsService.service.impl;

import java.util.HashSet;
import java.util.List;
import java.util.Optional;
import java.util.Set;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.core.userdetails.UsernameNotFoundException;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.stereotype.Service;

import com.dev.springboot.security.UserDetailsService.model.User;
import com.dev.springboot.security.UserDetailsService.repo.UserRepository;
import com.dev.springboot.security.UserDetailsService.service.IUserService;

@Service
public class UserServiceImpl implements IUserService, UserDetailsService{
	
	@Autowired
	private UserRepository userRepo;
	
	@Autowired
	private BCryptPasswordEncoder passwordEncoder;

	@Override
	public Integer saveUser(User user) {
		String passwd= user.getPassword();
		String encodedPasswod = passwordEncoder.encode(passwd);
		user.setPassword(encodedPasswod);
		user = userRepo.save(user);
		return user.getId();
	}

	@Override
	public UserDetails loadUserByUsername(String email) throws UsernameNotFoundException {

		Optional<User> opt = userRepo.findUserByEmail(email);
		
		org.springframework.security.core.userdetails.User springUser=null;
		
		if(opt.isEmpty()) {
			throw new UsernameNotFoundException("User with email: " +email +" not found");
		}else {
			User user =opt.get();	
			List<String> roles = user.getRoles();
			Set<GrantedAuthority> ga = new HashSet<>();
			for(String role:roles) {
				ga.add(new SimpleGrantedAuthority(role));
			}
			
			springUser = new org.springframework.security.core.userdetails.User(
							email,
							user.getPassword(),
							ga );
							
		}
		
		return springUser;
	}
	
}

Step#6 : Create a UserController class

Subsequently, write a controller class for User as ‘UserController.java’ which will control the user registration page.

UserController.java

package com.dev.springboot.security.UserDetailsService.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PostMapping;

import com.dev.springboot.security.UserDetailsService.model.User;
import com.dev.springboot.security.UserDetailsService.service.IUserService;

@Controller
public class UserController {

	@Autowired
	private IUserService userService;
	
	// Go to Registration Page
	@GetMapping("/register")
	public String register() {
		return "registerUser";
	}
	
	// Read Form data to save into DB
	@PostMapping("/saveUser")
	public String saveUser(
			@ModelAttribute User user,
			Model model
			) 
	{
		Integer id = userService.saveUser(user);
		String message = "User '"+id+"' saved successfully !";
		model.addAttribute("msg", message);
		return "registerUser";
	}
}

Step#7 : Write a Controller class to navigate through pages

In spite of UserController, write one more controller class and call it as ‘HomeController.java’. This class will be responsible to navigate through different pages.

HomeController.java

package com.dev.springboot.security.UserDetailsService.controller;

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

@Controller
public class HomeController {
	
	@GetMapping("/home")
	public String getHomePage() {
		return "homePage";
	}
	
	@GetMapping("/welcome")
	public String getWelcomePage() {
		return "welcomePage";
	}
	
	@GetMapping("/admin")
	public String getAdminPage() {
		return "adminPage";
	}
	
	@GetMapping("/emp")
	public String getEmployeePage() {
		return "empPage";
	}
	
	@GetMapping("/mgr")
	public String getManagerPage() {
		return "mgrPage";
	}
	
	@GetMapping("/hr")
	public String getHrPage() {
		return "hrPage";
	}
	
	@GetMapping("/common")
	public String getCommonPage() {
		return "commonPage";
	}
	
	@GetMapping("/accessDenied")
	public String getAccessDeniedPage() {
		return "accessDeniedPage";
	}
}

Step#8 : Write UI pages(Thymeleaf)

Below are the .html files for UI pages. Place these pages inside ‘src/main/resources/templates’ folder accordingly.

registerUser.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="ISO-8859-1">
<title>User Registration</title>
</head>
<body>
<h3>User Registration</h3>
<form action="saveUser" method="post">
<pre>
Name :    <input type="text" name="name"/>

Email:    <input type="text" name="email"/>

Password: <input type="password" name="password"/>

Role(s): <input type="checkbox" name="roles" value="Admin"/>Admin
         <input type="checkbox" name="roles" value="Manager"/>Manager
 	 <input type="checkbox" name="roles" value="HR"/>HR
	 <input type="checkbox" name="roles" value="Employee"/>Employee
<input type="hidden" th:name="${_csrf.parameterName}" th:value="${_csrf.token}"/>
    <input type="submit" value="Register"/>

</pre>
</form>
<div th:text="${msg}"></div>
</body>
</html>

homePage.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<h3> welcome to the Home Page </h3>
This page is accessible to ALL.
</body>
</html>

welcomePage.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<h3> Welcome Page after successful Login</h3>
<a th:href="@{/logout}" >LOGOUT</a>
</body>
</html>

adminPage.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<h3> Admin Page </h3>
Welcome to Admin page.!!!
<a th:href="@{/logout}" >LOGOUT</a>
</body>
</html>

empPage.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<h3> Employee Page </h3>
<a th:href="@{/logout}" >LOGOUT</a>
</body>
</html>

mgrPage.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<h3> Manager Page </h3>
<a th:href="@{/logout}" >LOGOUT</a>
</body>
</html>

hrPage.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<h3> HR Page </h3>
<a th:href="@{/logout}" >LOGOUT</a>
</body>
</html>

commonPage.html

	<!DOCTYPE html>
	<html xmlns:th="http://www.thymeleaf.org">
	<head>
	<meta charset="ISO-8859-1">
	<title>Insert title here</title>
	</head>
	<body>
	<h3>You are not allowed to access this page. Please go to Welcome Page</h3>
	<a th:href="@{/welcome}" >Welcome</a>
	<a th:href="@{/logout}" >LOGOUT</a>
	</body>
	</html>

accessDeniedPage.html

	<!DOCTYPE html>
	<html xmlns:th="http://www.thymeleaf.org">
	<head>
	<meta charset="ISO-8859-1">
	<title>Insert title here</title>
	</head>
	<body>
	<h3>You are not allowed to access this page. Please go to Welcome Page</h3>
	<a th:href="@{/welcome}" >Welcome</a>
	<a th:href="@{/logout}" >LOGOUT</a>
	</body>
	</html>

Step#9 : Write SecurityConfig class

In the end, write the other important class as SecurityConfig.java which will extend a predefined class WebSecurityConfigurerAdapter.java and implement two configure() methods accordingly as given below.

SecurityConfig.java

package com.dev.springboot.security.UserDetailsService.config;

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.UserDetailsService;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.security.web.util.matcher.AntPathRequestMatcher;

@EnableWebSecurity
@Configuration
public class SecurityConfig extends WebSecurityConfigurerAdapter {
	
	@Autowired
	private UserDetailsService uds;
	
	@Autowired
	private BCryptPasswordEncoder encoder;

	@Override
	protected void configure(AuthenticationManagerBuilder auth) throws Exception {
		
		auth.userDetailsService(uds).passwordEncoder(encoder);
	}
	
	@Override
	protected void configure(HttpSecurity http) throws Exception {
		
		http.authorizeRequests()
		.antMatchers("/home","/register","/saveUser").permitAll()
		.antMatchers("/welcome").authenticated()
		.antMatchers("/admin").hasAuthority("Admin")
		.antMatchers("/mgr").hasAuthority("Manager")
		.antMatchers("/emp").hasAuthority("Employee")
		.antMatchers("/hr").hasAuthority("HR")
		.antMatchers("/common").hasAnyAuthority("Employeee,Manager,Admin")
		.anyRequest().authenticated()
		
		.and()
		.formLogin()
		.defaultSuccessUrl("/welcome",true)
		
		.and()
		.logout()
		.logoutRequestMatcher(new AntPathRequestMatcher("/logout"))
		
		.and()
		.exceptionHandling()
		.accessDeniedPage("/accessDenied");
		
	}
}

Finally we have completed the coding part.

How to test the security enabled Application ?

Although the word ‘testing’ looks very easy to a developer, but it is equally important as it provides the result of our implementation on the whole. While testing the application you should keep configure(HttpSecurity http) method of SecurityConfig class in front of you, then follow the steps given below:

1) Start the application : Right click on the project, then select “Run As’ >> ‘Spring Boot App’.

2) Enter the registration page URL http://localhost:8080/register, then check if it is accessible to every one without even login to the application.

3) Enter the required field values and complete the registration process by clicking on the ‘Register’ button accordingly.

4) Now Enter any URL specific to the role you selected in registration. Suppose you entered URL http://localhost:8080/admin, then it should redirect you to the in-built Login page.

5) Enter the credentials(email id in place of username) and Login to the application. It will redirect you to the default success URL which is welcome page.

6) Now enter the URL http://localhost:8080/admin again, this time you will be able to access the admin page.

7) Repeat the above steps for other roles as well.

Additionally, as mentioned above keep the code in front of you and test each scenario subsequently.

Summary

After going through all the theoretical & examples part of ‘How to implement Security in Spring Boot using UserDetailsService?’, finally, we are able to implement web security in a Spring Boot project. Of course, In this article we have covered the third way of implementing security feature. Similarly, we will talk about some more ways of security like REST security in our upcoming articles. If there is any change in the future, we will update the same accordingly. If you want to learn more about Spring Security, kindly visit spring.io documentation. Moreover, Feel free to provide your comments in the comments section.

26 thoughts on “How to implement Security in Spring Boot using UserDetailsService?”

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