Login and Registration REST API with Spring Security

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In this example, we will learn how to implement login and registration REST API using spring boot, spring security, hibernate and the H2 database.
We will create an example of Spring Boot REST application where we will build two web services. One web service of user registration and the other is for user login.

Table of Content

1. Keep Eclipse IDE ready(STS integrated)
2. Create a Spring Boot Starter Project 
3. Maven Dependency
4. Define Database configuration in the application.properties file
5. Create entity class
6. Create a repository
7. Create a service
8. Create a DTO class
9. Create a Controller class
10. Create a Spring Security Config class
11. Insert data in the database using SpringBootApplication class
12. Run the Application
13. Conclusion

1. Keep Eclipse IDE ready(STS integrated)

Refer to this article How to Create Spring Project in IDE  to create Spring Boot Project in Eclipse IDE.

2. Create a Spring Boot Starter Project 

Add the following dependencies: 
• Spring Web 
• Spring Security
• H2 Database
• Spring Data JPA

login_and_registration_rest_api_with_spring_security

3. Maven Dependency

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.11</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.springjava</groupId>
    <artifactId>Login_Registration_Rest_Api_Spring_Security</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>Login_Registration_Rest_Api_Spring_Security</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>16</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <scope>runtime</scope>
        </dependency>    
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

4. Define Database configuration in the application.properties file

spring.datasource.url=jdbc:h2:mem:test
spring.datasource.username=sa
spring.datasource.password=
spring.jpa.show-sql=true
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.H2Dialect
spring.jpa.hibernate.ddl-auto=update
spring.h2.console.enabled=true
server.port=8888

5. Create entity class

Role.java

package com.springjava.entity;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="roles")
public class Role {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;
    private String name;

    public Role() {

    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

}

User.java

package com.springjava.entity;

import java.util.Set;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.ManyToMany;
import javax.persistence.Table;

import org.hibernate.annotations.LazyCollection;
import org.hibernate.annotations.LazyCollectionOption;

@Entity
@Table(name="users")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;
    private String name;
    @Column(nullable = false, unique = true)
    private String userName;
    @Column(nullable = false, unique = true)
    private String email;
    @Column(nullable = false)
    private String password;
    @ManyToMany
    @LazyCollection(LazyCollectionOption.FALSE)
    private Set<Role> roles;
    public Integer getId() {
          return id;
      }

      public void setId(Integer id) {
          this.id = id;
      }

      public String getName() {
          return name;
      }

      public void setName(String name) {
          this.name = name;
      }

      public String getUserName() {
          return userName;
      }

      public void setUserName(String username) {
          this.userName = username;
      }

      public String getEmail() {
          return email;
      }

      public void setEmail(String email) {
          this.email = email;
      }

      public String getPassword() {
          return password;
      }

      public void setPassword(String password) {
          this.password = password;
      }

      public Set<Role> getRoles() {
          return roles;
      }

      public void setRoles(Set<Role> roles) {
          this.roles = roles;
      }
}

6. Create a repository

RoleRepository.java

package com.springjava.repository;
import java.util.Optional;
import org.springframework.data.jpa.repository.JpaRepository;
import com.springjava.entity.Role;
public interface RoleRepository extends JpaRepository<Role, Integer> {
Optional<Role> findByName(String name);
}

UserRepository.java 

package com.springjava.repository;
import org.springframework.data.jpa.repository.JpaRepository;
import com.springjava.entity.User;
public interface UserRepository extends JpaRepository<User, Integer> {
User findByUsernameOrEmail(String username, String email);
}

7. Create a service

UserDetail.java

package com.springjava.service;
import java.util.Set;
import java.util.stream.Collectors;
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.stereotype.Service;
import com.springjava.entity.User;
import com.springjava.repository.UserRepository;

@Service
public class UserDetail implements UserDetailsService {
@Autowired    
UserRepository userRepo;

    @Override
    public UserDetails loadUserByUsername(String username)throws UsernameNotFoundException {
        User user = userRepo.findByUserNameOrEmail(username, username);
        if(user==null){
            throw new UsernameNotFoundException("User not exists by Username");
        }
           
        Set<GrantedAuthority> authorities = user.getRoles().stream()
                .map((role) -> new SimpleGrantedAuthority(role.getName()))
                .collect(Collectors.toSet());

        return new org.springframework.security.core.userdetails.User(username,user.getPassword(),authorities);
    }
}

8. Create a DTO class

LoginDto.java

package com.springjava.dto;

public class LoginDto {
    private String username;
    private String password;   
    public LoginDto() {      }   
    public String getUsername() {      
        return username;   
    }   
    public void setUsername(String username) {      
        this.username = username;   
    }   
    public String getPassword() {      
        return password;   
    }   
    public void setPassword(String password) {      
        this.password = password;   
    }
}

SignUpDto.java

package com.springjava.dto;

public class SignUpDto {
    private String name;
    private String username;
    private String email;
    private String password;

    public SignUpDto() {

    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

9. Create a Controller class

HomeController.java

package com.springjava.controller;

import java.util.Collections;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.springjava.dto.LoginDto;
import com.springjava.dto.SignUpDto;
import com.springjava.entity.Role;
import com.springjava.entity.User;
import com.springjava.repository.RoleRepository;
import com.springjava.repository.UserRepository;


@RestController
@RequestMapping("/api")
public class HomeController {
    @Autowired
    private AuthenticationManager authenticationManager;
    @Autowired
    private UserRepository userRepository;

    @Autowired
    private RoleRepository roleRepository;

    @Autowired
    private PasswordEncoder passwordEncoder;
    

    @PostMapping("/login")
    public ResponseEntity<String> authenticateUser(@RequestBody LoginDto loginDto) {
        Authentication authentication = authenticationManager
                .authenticate(new UsernamePasswordAuthenticationToken(loginDto.getUsername(), loginDto.getPassword()));

        SecurityContextHolder.getContext().setAuthentication(authentication);
        return new ResponseEntity<>("User login successfully!...", HttpStatus.OK);
    }
    
    
        @PostMapping("/signup")
        public ResponseEntity<?> registerUser(@RequestBody SignUpDto signUpDto){

            // checking for username exists in a database
            if(userRepository.existsByUserName(signUpDto.getUsername())){
                return new ResponseEntity<>("Username is already exist!", HttpStatus.BAD_REQUEST);
            }

            // checking for email exists in a database
            if(userRepository.existsByEmail(signUpDto.getEmail())){
                return new ResponseEntity<>("Email is already exist!", HttpStatus.BAD_REQUEST);
            }

            // creating user object
            User user = new User();
            user.setName(signUpDto.getName());
            user.setUserName(signUpDto.getUsername());
            user.setEmail(signUpDto.getEmail());
            user.setPassword(passwordEncoder.encode(signUpDto.getPassword()));

            Role roles = roleRepository.findByName("ROLE_ADMIN").get();
            user.setRoles(Collections.singleton(roles));

            userRepository.save(user);

            return new ResponseEntity<>("User is registered successfully!", HttpStatus.OK);

        }
}

10. Create a Spring Security Config class

SecurityConfig.java

package com.springjava.security;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.config.annotation.authentication.configuration.AuthenticationConfiguration;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.security.web.SecurityFilterChain;

@Configuration
public class SecurityConfig {

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

    @Bean
    public AuthenticationManager authenticationManager(AuthenticationConfiguration configuration) throws Exception {
        return configuration.getAuthenticationManager();
    }

    @Bean
    SecurityFilterChain securityFilterChain(HttpSecurity http) throws Exception {

        http.csrf().disable()
        .authorizeRequests().antMatchers("/api/**", "/h2-console/**").permitAll()
        .anyRequest().authenticated();
        http.headers().frameOptions().disable();

        return http.build();
    }
}

11. Insert data in the database using SpringBootApplication class

package com.springjava;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;

import com.springjava.entity.Role;
import com.springjava.repository.RoleRepository;

@SpringBootApplication
public class LoginRegistrationRestApiSpringSecurityApplication {

    public static void main(String[] args) {
        SpringApplication.run(LoginRegistrationRestApiSpringSecurityApplication.class, args);
    }
    
    @Bean
    public CommandLineRunner demo(RoleRepository roleRepo) {
        return (args) -> {
            Role role=new Role();
            role.setName("ROLE_ADMIN");
            roleRepo.save(role);
        };
    }
}

12. Run the Application

To run this application right-click on the SpringBootApplication class, click Run As, then select the Java Application option.
Testing the API in Postman

login_and_registration_rest_api_with_spring_security
login_and_registration_rest_api_with_spring_security

To Check the H2 Database browse this URL http://localhost:8888/h2-console/

login_and_registration_rest_api_with_spring_security

13. Conclusion

In this example, we learnt how to implement spring security login and registration rest API in the spring boot example.

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