spring-boot-authentication-jwt-spring-security-feature-image

Secure Spring Boot App with Spring Security & JWT Authentication

In this tutorial, we’re gonna build a Spring Boot Application that supports JWT Authentication. You’ll know:

  • Appropriate Flow for User Signup & User Login with JWT Authentication
  • Spring Boot Application Architecture with Spring Security
  • How to configure Spring Security to work with JWT
  • How to define Data Models and association for Authentication and Authorization
  • Way to use Spring Data JPA to interact with PostgreSQL/MySQL Database

Lots of interesting things ahead, let’s explore together.

More Practice: CRUD GraphQL APIs example with Spring Boot, MySQL & Spring JPA


Overview of Spring Boot JWT Authentication example

We will build a Spring Boot application in that:

  • User can signup new account, or login with username & password.
  • By User’s role (admin, moderator, user), we authorize the User to access resources

These are APIs that we need to provide:

MethodsUrlsActions
POST/api/auth/signupsignup new account
POST/api/auth/signinlogin an account
GET/api/test/allretrieve public content
GET/api/test/useraccess User’s content
GET/api/test/modaccess Moderator’s content
GET/api/test/adminaccess Admin’s content

The database we will use could be PostgreSQL or MySQL depending on the way we configure project dependency & datasource.

Spring Boot Signup & Login with JWT Authentication Flow

The diagram shows flow of how we implement User Registration, User Login and Authorization process.

spring-boot-authentication-jwt-spring-security-flow

A legal JWT must be added to HTTP Authorization Header if Client accesses protected resources.

Spring Boot Server Architecture with Spring Security

You can have an overview of our Spring Boot Server with the diagram below:

spring-boot-authentication-spring-security-architecture

Now I will explain it briefly.

Spring Security

WebSecurityConfigurerAdapter is the crux of our security implementation. It provides HttpSecurity configurations to configure cors, csrf, session management, rules for protected resources. We can also extend and customize the default configuration that contains the elements below.

UserDetailsService interface has a method to load User by username and returns a UserDetails object that Spring Security can use for authentication and validation.

UserDetails contains necessary information (such as: username, password, authorities) to build an Authentication object.

UsernamePasswordAuthenticationToken gets {username, password} from login Request, AuthenticationManager will use it to authenticate a login account.

AuthenticationManager has a DaoAuthenticationProvider (with help of UserDetailsService & PasswordEncoder) to validate UsernamePasswordAuthenticationToken object. If successful, AuthenticationManager returns a fully populated Authentication object (including granted authorities).

OncePerRequestFilter makes a single execution for each request to our API. It provides a doFilterInternal() method that we will implement parsing & validating JWT, loading User details (using UserDetailsService), checking Authorizaion (using UsernamePasswordAuthenticationToken).

AuthenticationEntryPoint will catch unauthorized error and return a 401 when Clients access protected resources without authentication.

Repository contains UserRepository & RoleRepository to work with Database, will be imported into Controller.

Controller receives and handles request after it was filtered by OncePerRequestFilter.

AuthController handles signup/login requests

TestController has accessing protected resource methods with role based validations.

Technology

  • Java 8
  • Spring Boot 2.1.8 (with Spring Security, Spring Web, Spring Data JPA)
  • jjwt 0.9.1
  • PostgreSQL/MySQL
  • Maven 3.6.1

Project Structure

This is folders & files structure for our Spring Boot application:

spring-boot-authentication-spring-security-project-structure

security: we configure Spring Security & implement Security Objects here.

  • WebSecurityConfig extends WebSecurityConfigurerAdapter
  • UserDetailsServiceImpl implements UserDetailsService
  • UserDetailsImpl implements UserDetails
  • AuthEntryPointJwt implements AuthenticationEntryPoint
  • AuthTokenFilter extends OncePerRequestFilter
  • JwtUtils provides methods for generating, parsing, validating JWT

controllers handle signup/login requests & authorized requests.

  • AuthController: @PostMapping(‘/signin’), @PostMapping(‘/signup’)
  • TestController: @GetMapping(‘/api/test/all’), @GetMapping(‘/api/test/[role]’)

repository has intefaces that extend Spring Data JPA JpaRepository to interact with Database.

  • UserRepository extends JpaRepository
  • RoleRepository extends JpaRepository

models defines two main models for Authentication (User) & Authorization (Role). They have many-to-many relationship.

  • User: id, username, email, password, roles
  • Role: id, name

payload defines classes for Request and Response objects

We also have application.properties for configuring Spring Datasource, Spring Data JPA and App properties (such as JWT Secret string or Token expiration time).

Setup new Spring Boot project

Use Spring web tool or your development tool (Spring Tool Suite, Eclipse, Intellij) to create a Spring Boot project.

Then open pom.xml and add these dependencies:

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

<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>io.jsonwebtoken</groupId>
	<artifactId>jjwt</artifactId>
	<version>0.9.1</version>
</dependency>

We also need to add one more dependency.
– If you want to use PostgreSQL:

<dependency>
	<groupId>org.postgresql</groupId>
	<artifactId>postgresql</artifactId>
	<scope>runtime</scope>
</dependency>

– or MySQL is your choice:

<dependency>
	<groupId>mysql</groupId>
	<artifactId>mysql-connector-java</artifactId>
	<scope>runtime</scope>
</dependency>

Configure Spring Datasource, JPA, App properties

Under src/main/resources folder, open application.properties, add some new lines.

For PostgreSQL

spring.datasource.url= jdbc:postgresql://localhost:5432/testdb
spring.datasource.username= postgres
spring.datasource.password= 123

spring.jpa.properties.hibernate.jdbc.lob.non_contextual_creation= true
spring.jpa.properties.hibernate.dialect= org.hibernate.dialect.PostgreSQLDialect

# Hibernate ddl auto (create, create-drop, validate, update)
spring.jpa.hibernate.ddl-auto= update

# App Properties
bezkoder.app.jwtSecret= bezKoderSecretKey
bezkoder.app.jwtExpirationMs= 86400000

For MySQL

spring.datasource.url= jdbc:mysql://localhost:3306/testdb?useSSL=false
spring.datasource.username= root
spring.datasource.password= 123456

spring.jpa.properties.hibernate.dialect= org.hibernate.dialect.MySQL5InnoDBDialect
spring.jpa.hibernate.ddl-auto= update

# App Properties
bezkoder.app.jwtSecret= bezKoderSecretKey
bezkoder.app.jwtExpirationMs= 86400000

Create the models

We’re gonna have 3 tables in database: users, roles and user_roles for many-to-many relationship.

Let’s define these models.
In models package, create 3 files:

ERole enum in ERole.java.
In this example, we have 3 roles corresponding to 3 enum.

package com.bezkoder.springjwt.models;

public enum ERole {
	ROLE_USER,
    ROLE_MODERATOR,
    ROLE_ADMIN
}

Role model in Role.java

package com.bezkoder.springjwt.models;

import javax.persistence.*;

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

	@Enumerated(EnumType.STRING)
	@Column(length = 20)
	private ERole name;

	public Role() {

	}

	public Role(ERole name) {
		this.name = name;
	}

	public Integer getId() {
		return id;
	}

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

	public ERole getName() {
		return name;
	}

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

User model in User.java.
It has 5 fields: id, username, email, password, roles.

package com.bezkoder.springjwt.models;

import java.util.HashSet;
import java.util.Set;

import javax.persistence.*;
import javax.validation.constraints.Email;
import javax.validation.constraints.NotBlank;
import javax.validation.constraints.Size;

@Entity
@Table(	name = "users", 
		uniqueConstraints = { 
			@UniqueConstraint(columnNames = "username"),
			@UniqueConstraint(columnNames = "email") 
		})
public class User {
	@Id
	@GeneratedValue(strategy = GenerationType.IDENTITY)
	private Long id;

	@NotBlank
	@Size(max = 20)
	private String username;

	@NotBlank
	@Size(max = 50)
	@Email
	private String email;

	@NotBlank
	@Size(max = 120)
	private String password;

	@ManyToMany(fetch = FetchType.LAZY)
	@JoinTable(	name = "user_roles", 
				joinColumns = @JoinColumn(name = "user_id"), 
				inverseJoinColumns = @JoinColumn(name = "role_id"))
	private Set roles = new HashSet<>();

	public User() {
	}

	public User(String username, String email, String password) {
		this.username = username;
		this.email = email;
		this.password = password;
	}

	public Long getId() {
		return id;
	}

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

	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 getRoles() {
		return roles;
	}

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

Implement Repositories

Now, each model above needs a repository for persisting and accessing data. In repository package, let’s create 2 repositories.

UserRepository

There are 3 necessary methods that JpaRepository supports.

package com.bezkoder.springjwt.repository;

import java.util.Optional;

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

import com.bezkoder.springjwt.models.User;

@Repository
public interface UserRepository extends JpaRepository {
	Optional findByUsername(String username);

	Boolean existsByUsername(String username);

	Boolean existsByEmail(String email);
}

RoleRepository

This repository also extends JpaRepository and provides a finder method.

package com.bezkoder.springjwt.repository;

import java.util.Optional;

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

import com.bezkoder.springjwt.models.ERole;
import com.bezkoder.springjwt.models.Role;

@Repository
public interface RoleRepository extends JpaRepository {
	Optional findByName(ERole name);
}

Configure Spring Security

In security package, create WebSecurityConfig class that extends WebSecurityConfigurerAdapter.

WebSecurityConfig.java

package com.bezkoder.springjwt.security;

import org.springframework.beans.factory.annotation.Autowired;
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.builders.AuthenticationManagerBuilder;
import org.springframework.security.config.annotation.method.configuration.EnableGlobalMethodSecurity;
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.config.http.SessionCreationPolicy;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;

import com.bezkoder.springjwt.security.jwt.AuthEntryPointJwt;
import com.bezkoder.springjwt.security.jwt.AuthTokenFilter;
import com.bezkoder.springjwt.security.services.UserDetailsServiceImpl;

@Configuration
@EnableWebSecurity
@EnableGlobalMethodSecurity(
		// securedEnabled = true,
		// jsr250Enabled = true,
		prePostEnabled = true)
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {
	@Autowired
	UserDetailsServiceImpl userDetailsService;

	@Autowired
	private AuthEntryPointJwt unauthorizedHandler;

	@Bean
	public AuthTokenFilter authenticationJwtTokenFilter() {
		return new AuthTokenFilter();
	}

	@Override
	public void configure(AuthenticationManagerBuilder authenticationManagerBuilder) throws Exception {
		authenticationManagerBuilder.userDetailsService(userDetailsService).passwordEncoder(passwordEncoder());
	}

	@Bean
	@Override
	public AuthenticationManager authenticationManagerBean() throws Exception {
		return super.authenticationManagerBean();
	}

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

	@Override
	protected void configure(HttpSecurity http) throws Exception {
		http.cors().and().csrf().disable()
			.exceptionHandling().authenticationEntryPoint(unauthorizedHandler).and()
			.sessionManagement().sessionCreationPolicy(SessionCreationPolicy.STATELESS).and()
			.authorizeRequests().antMatchers("/api/auth/**").permitAll()
			.antMatchers("/api/test/**").permitAll()
			.anyRequest().authenticated();

		http.addFilterBefore(authenticationJwtTokenFilter(), UsernamePasswordAuthenticationFilter.class);
	}
}

Let me explain the code above.

@EnableWebSecurity allows Spring to find and automatically apply the class to the global Web Security.

@EnableGlobalMethodSecurity provides AOP security on methods. It enables @PreAuthorize, @PostAuthorize, it also supports JSR-250. You can find more parameters in configuration in Method Security Expressions.

– We override the configure(HttpSecurity http) method from WebSecurityConfigurerAdapter interface. It tells Spring Security how we configure CORS and CSRF, when we want to require all users to be authenticated or not, which filter (AuthTokenFilter) and when we want it to work (filter before UsernamePasswordAuthenticationFilter), which Exception Handler is chosen (AuthEntryPointJwt).

– Spring Security will load User details to perform authentication & authorization. So it has UserDetailsService interface that we need to implement.

– The implementation of UserDetailsService will be used for configuring DaoAuthenticationProvider by AuthenticationManagerBuilder.userDetailsService() method.

– We also need a PasswordEncoder for the DaoAuthenticationProvider. If we don’t specify, it will use plain text.

Implement UserDetails & UserDetailsService

If the authentication process is successful, we can get User’s information such as username, password, authorities from an Authentication object.

Authentication authentication = 
        authenticationManager.authenticate(
            new UsernamePasswordAuthenticationToken(username, password)
        );

UserDetails userDetails = (UserDetails) authentication.getPrincipal();
// userDetails.getUsername()
// userDetails.getPassword()
// userDetails.getAuthorities()

If we want to get more data (id, email…), we can create an implementation of this UserDetails interface.

security/services/UserDetailsImpl.java

package com.bezkoder.springjwt.security.services;

import java.util.Collection;
import java.util.List;
import java.util.Objects;
import java.util.stream.Collectors;

import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.security.core.userdetails.UserDetails;

import com.bezkoder.springjwt.models.User;
import com.fasterxml.jackson.annotation.JsonIgnore;

public class UserDetailsImpl implements UserDetails {
	private static final long serialVersionUID = 1L;

	private Long id;

	private String username;

	private String email;

	@JsonIgnore
	private String password;

	private Collection authorities;

	public UserDetailsImpl(Long id, String username, String email, String password,
			Collection authorities) {
		this.id = id;
		this.username = username;
		this.email = email;
		this.password = password;
		this.authorities = authorities;
	}

	public static UserDetailsImpl build(User user) {
		List authorities = user.getRoles().stream()
				.map(role -> new SimpleGrantedAuthority(role.getName().name()))
				.collect(Collectors.toList());

		return new UserDetailsImpl(
				user.getId(), 
				user.getUsername(), 
				user.getEmail(),
				user.getPassword(), 
				authorities);
	}

	@Override
	public Collection getAuthorities() {
		return authorities;
	}

	public Long getId() {
		return id;
	}

	public String getEmail() {
		return email;
	}

	@Override
	public String getPassword() {
		return password;
	}

	@Override
	public String getUsername() {
		return username;
	}

	@Override
	public boolean isAccountNonExpired() {
		return true;
	}

	@Override
	public boolean isAccountNonLocked() {
		return true;
	}

	@Override
	public boolean isCredentialsNonExpired() {
		return true;
	}

	@Override
	public boolean isEnabled() {
		return true;
	}

	@Override
	public boolean equals(Object o) {
		if (this == o)
			return true;
		if (o == null || getClass() != o.getClass())
			return false;
		UserDetailsImpl user = (UserDetailsImpl) o;
		return Objects.equals(id, user.id);
	}
}

Look at the code above, you can notice that we convert Set<Role> into List<GrantedAuthority>. It is important to work with Spring Security and Authentication object later.

As I have said before, we need UserDetailsService for getting UserDetails object. You can look at UserDetailsService interface that has only one method:

public interface UserDetailsService {
    UserDetails loadUserByUsername(String username) throws UsernameNotFoundException;
}

So we implement it and override loadUserByUsername() method.

security/services/UserDetailsImpl.java

package com.bezkoder.springjwt.security.services;

import org.springframework.beans.factory.annotation.Autowired;
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 org.springframework.transaction.annotation.Transactional;

import com.bezkoder.springjwt.models.User;
import com.bezkoder.springjwt.repository.UserRepository;

@Service
public class UserDetailsServiceImpl implements UserDetailsService {
	@Autowired
	UserRepository userRepository;

	@Override
	@Transactional
	public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
		User user = userRepository.findByUsername(username)
				.orElseThrow(() -> new UsernameNotFoundException("User Not Found with username: " + username));

		return UserDetailsImpl.build(user);
	}

}

In the code above, we get full custom User object using UserRepository, then we build a UserDetails object using static build() method.

Filter the Requests

Let’s define a filter that executes once per request. So we create AuthTokenFilter class that extends OncePerRequestFilter and override doFilterInternal() method.

security/jwt/AuthTokenFilter.java

package com.bezkoder.springjwt.security.jwt;

import java.io.IOException;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.web.authentication.WebAuthenticationDetailsSource;
import org.springframework.util.StringUtils;
import org.springframework.web.filter.OncePerRequestFilter;

import com.bezkoder.springjwt.security.services.UserDetailsServiceImpl;

public class AuthTokenFilter extends OncePerRequestFilter {
	@Autowired
	private JwtUtils jwtUtils;

	@Autowired
	private UserDetailsServiceImpl userDetailsService;

	private static final Logger logger = LoggerFactory.getLogger(AuthTokenFilter.class);

	@Override
	protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
			throws ServletException, IOException {
		try {
			String jwt = parseJwt(request);
			if (jwt != null && jwtUtils.validateJwtToken(jwt)) {
				String username = jwtUtils.getUserNameFromJwtToken(jwt);

				UserDetails userDetails = userDetailsService.loadUserByUsername(username);
				UsernamePasswordAuthenticationToken authentication = new UsernamePasswordAuthenticationToken(
						userDetails, null, userDetails.getAuthorities());
				authentication.setDetails(new WebAuthenticationDetailsSource().buildDetails(request));

				SecurityContextHolder.getContext().setAuthentication(authentication);
			}
		} catch (Exception e) {
			logger.error("Cannot set user authentication: {}", e);
		}

		filterChain.doFilter(request, response);
	}

	private String parseJwt(HttpServletRequest request) {
		String headerAuth = request.getHeader("Authorization");

		if (StringUtils.hasText(headerAuth) && headerAuth.startsWith("Bearer ")) {
			return headerAuth.substring(7, headerAuth.length());
		}

		return null;
	}
}

What we do inside doFilterInternal():
– get JWT from the Authorization header (by removing Bearer prefix)
– if the request has JWT, validate it, parse username from it
– from username, get UserDetails to create an Authentication object
– set the current UserDetails in SecurityContext using setAuthentication(authentication) method.

After this, everytime you want to get UserDetails, just use SecurityContext like this:

UserDetails userDetails =
	(UserDetails) SecurityContextHolder.getContext().getAuthentication().getPrincipal();

// userDetails.getUsername()
// userDetails.getPassword()
// userDetails.getAuthorities()

Create JWT Utility class

This class has 3 funtions:

  • generate a JWT from username, date, expiration, secret
  • get username from JWT
  • validate a JWT

security/jwt/JwtUtils.java

package com.bezkoder.springjwt.security.jwt;

import java.util.Date;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.security.core.Authentication;
import org.springframework.stereotype.Component;

import com.bezkoder.springjwt.security.services.UserDetailsImpl;
import io.jsonwebtoken.*;

@Component
public class JwtUtils {
	private static final Logger logger = LoggerFactory.getLogger(JwtUtils.class);

	@Value("${bezkoder.app.jwtSecret}")
	private String jwtSecret;

	@Value("${bezkoder.app.jwtExpirationMs}")
	private int jwtExpirationMs;

	public String generateJwtToken(Authentication authentication) {

		UserDetailsImpl userPrincipal = (UserDetailsImpl) authentication.getPrincipal();

		return Jwts.builder()
				.setSubject((userPrincipal.getUsername()))
				.setIssuedAt(new Date())
				.setExpiration(new Date((new Date()).getTime() + jwtExpirationMs))
				.signWith(SignatureAlgorithm.HS512, jwtSecret)
				.compact();
	}

	public String getUserNameFromJwtToken(String token) {
		return Jwts.parser().setSigningKey(jwtSecret).parseClaimsJws(token).getBody().getSubject();
	}

	public boolean validateJwtToken(String authToken) {
		try {
			Jwts.parser().setSigningKey(jwtSecret).parseClaimsJws(authToken);
			return true;
		} catch (SignatureException e) {
			logger.error("Invalid JWT signature: {}", e.getMessage());
		} catch (MalformedJwtException e) {
			logger.error("Invalid JWT token: {}", e.getMessage());
		} catch (ExpiredJwtException e) {
			logger.error("JWT token is expired: {}", e.getMessage());
		} catch (UnsupportedJwtException e) {
			logger.error("JWT token is unsupported: {}", e.getMessage());
		} catch (IllegalArgumentException e) {
			logger.error("JWT claims string is empty: {}", e.getMessage());
		}

		return false;
	}
}

Remember that we’ve added bezkoder.app.jwtSecret and bezkoder.app.jwtExpirationMs properties in application.properties file.

Handle Authentication Exception

Now we create AuthEntryPointJwt class that implements AuthenticationEntryPoint interface. Then we override the commence() method. This method will be triggerd anytime unauthenticated User requests a secured HTTP resource and an AuthenticationException is thrown.

security/jwt/AuthEntryPointJwt.java

package com.bezkoder.springjwt.security.jwt;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.web.AuthenticationEntryPoint;
import org.springframework.stereotype.Component;

@Component
public class AuthEntryPointJwt implements AuthenticationEntryPoint {

	private static final Logger logger = LoggerFactory.getLogger(AuthEntryPointJwt.class);

	@Override
	public void commence(HttpServletRequest request, HttpServletResponse response,
			AuthenticationException authException) throws IOException, ServletException {
		logger.error("Unauthorized error: {}", authException.getMessage());
		response.sendError(HttpServletResponse.SC_UNAUTHORIZED, "Error: Unauthorized");
	}

}

HttpServletResponse.SC_UNAUTHORIZED is the 401 Status code. It indicates that the request requires HTTP authentication.

We’ve already built all things for Spring Security. The next sections of this tutorial will show you how to implement Controllers for our RestAPIs.

Define payloads for Spring RestController

Let me summarize the payloads for our RestAPIs:
– Requests:

  • LoginRequest: { username, password }
  • SignupRequest: { username, email, password }

– Responses:

  • JwtResponse: { token, type, id, username, email, roles }
  • MessageResponse: { message }

To keep the tutorial not so long, I don’t show these POJOs here.
You can find details for payload classes in source code of the project on Github.

Create Spring RestAPIs Controllers

Controller for Authentication

This controller provides APIs for register and login actions.

/api/auth/signup

  • check existing username/email
  • create new User (with ROLE_USER if not specifying role)
  • save User to database using UserRepository

/api/auth/signin

  • authenticate { username, pasword }
  • update SecurityContext using Authentication object
  • generate JWT
  • get UserDetails from Authentication object
  • response contains JWT and UserDetails data

controllers/AuthController.java

package com.bezkoder.springjwt.controllers;

import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

import javax.validation.Valid;

import org.springframework.beans.factory.annotation.Autowired;
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.CrossOrigin;
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.bezkoder.springjwt.models.ERole;
import com.bezkoder.springjwt.models.Role;
import com.bezkoder.springjwt.models.User;
import com.bezkoder.springjwt.payload.request.LoginRequest;
import com.bezkoder.springjwt.payload.request.SignupRequest;
import com.bezkoder.springjwt.payload.response.JwtResponse;
import com.bezkoder.springjwt.payload.response.MessageResponse;
import com.bezkoder.springjwt.repository.RoleRepository;
import com.bezkoder.springjwt.repository.UserRepository;
import com.bezkoder.springjwt.security.jwt.JwtUtils;
import com.bezkoder.springjwt.security.services.UserDetailsImpl;

@CrossOrigin(origins = "*", maxAge = 3600)
@RestController
@RequestMapping("/api/auth")
public class AuthController {
	@Autowired
	AuthenticationManager authenticationManager;

	@Autowired
	UserRepository userRepository;

	@Autowired
	RoleRepository roleRepository;

	@Autowired
	PasswordEncoder encoder;

	@Autowired
	JwtUtils jwtUtils;

	@PostMapping("/signin")
	public ResponseEntity authenticateUser(@Valid @RequestBody LoginRequest loginRequest) {

		Authentication authentication = authenticationManager.authenticate(
				new UsernamePasswordAuthenticationToken(loginRequest.getUsername(), loginRequest.getPassword()));

		SecurityContextHolder.getContext().setAuthentication(authentication);
		String jwt = jwtUtils.generateJwtToken(authentication);
		
		UserDetailsImpl userDetails = (UserDetailsImpl) authentication.getPrincipal();		
		List roles = userDetails.getAuthorities().stream()
				.map(item -> item.getAuthority())
				.collect(Collectors.toList());

		return ResponseEntity.ok(new JwtResponse(jwt, 
												 userDetails.getId(), 
												 userDetails.getUsername(), 
												 userDetails.getEmail(), 
												 roles));
	}

	@PostMapping("/signup")
	public ResponseEntity registerUser(@Valid @RequestBody SignupRequest signUpRequest) {
		if (userRepository.existsByUsername(signUpRequest.getUsername())) {
			return ResponseEntity
					.badRequest()
					.body(new MessageResponse("Error: Username is already taken!"));
		}

		if (userRepository.existsByEmail(signUpRequest.getEmail())) {
			return ResponseEntity
					.badRequest()
					.body(new MessageResponse("Error: Email is already in use!"));
		}

		// Create new user's account
		User user = new User(signUpRequest.getUsername(), 
							 signUpRequest.getEmail(),
							 encoder.encode(signUpRequest.getPassword()));

		Set strRoles = signUpRequest.getRole();
		Set roles = new HashSet<>();

		if (strRoles == null) {
			Role userRole = roleRepository.findByName(ERole.ROLE_USER)
					.orElseThrow(() -> new RuntimeException("Error: Role is not found."));
			roles.add(userRole);
		} else {
			strRoles.forEach(role -> {
				switch (role) {
				case "admin":
					Role adminRole = roleRepository.findByName(ERole.ROLE_ADMIN)
							.orElseThrow(() -> new RuntimeException("Error: Role is not found."));
					roles.add(adminRole);

					break;
				case "mod":
					Role modRole = roleRepository.findByName(ERole.ROLE_MODERATOR)
							.orElseThrow(() -> new RuntimeException("Error: Role is not found."));
					roles.add(modRole);

					break;
				default:
					Role userRole = roleRepository.findByName(ERole.ROLE_USER)
							.orElseThrow(() -> new RuntimeException("Error: Role is not found."));
					roles.add(userRole);
				}
			});
		}

		user.setRoles(roles);
		userRepository.save(user);

		return ResponseEntity.ok(new MessageResponse("User registered successfully!"));
	}
}

Controller for testing Authorization

There are 4 APIs:
/api/test/all for public access
/api/test/user for users has ROLE_USER or ROLE_MODERATOR or ROLE_ADMIN
/api/test/mod for users has ROLE_MODERATOR
/api/test/admin for users has ROLE_ADMIN

Do you remember that we used @EnableGlobalMethodSecurity(prePostEnabled = true) for WebSecurityConfig class?

@Configuration
@EnableWebSecurity
@EnableGlobalMethodSecurity(prePostEnabled = true)
public class WebSecurityConfig extends WebSecurityConfigurerAdapter { ... }

Now we can secure methods in our Apis with @PreAuthorize annotation easily.

controllers/TestController.java

package com.bezkoder.springjwt.controllers;

import org.springframework.security.access.prepost.PreAuthorize;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@CrossOrigin(origins = "*", maxAge = 3600)
@RestController
@RequestMapping("/api/test")
public class TestController {
	@GetMapping("/all")
	public String allAccess() {
		return "Public Content.";
	}
	
	@GetMapping("/user")
	@PreAuthorize("hasRole('USER') or hasRole('MODERATOR') or hasRole('ADMIN')")
	public String userAccess() {
		return "User Content.";
	}

	@GetMapping("/mod")
	@PreAuthorize("hasRole('MODERATOR')")
	public String moderatorAccess() {
		return "Moderator Board.";
	}

	@GetMapping("/admin")
	@PreAuthorize("hasRole('ADMIN')")
	public String adminAccess() {
		return "Admin Board.";
	}
}

Run & Test

Run Spring Boot application with command: mvn spring-boot:run

Tables that we define in models package will be automatically generated in Database.
If you check PostgreSQL for example, you can see things like this:

\d users
                                  Table "public.users"
  Column  |          Type          |                     Modifiers
----------+------------------------+----------------------------------------------------
 id       | bigint                 | not null default nextval('users_id_seq'::regclass)
 email    | character varying(50)  |
 password | character varying(120) |
 username | character varying(20)  |
Indexes:
    "users_pkey" PRIMARY KEY, btree (id)
    "uk6dotkott2kjsp8vw4d0m25fb7" UNIQUE CONSTRAINT, btree (email)
    "ukr43af9ap4edm43mmtq01oddj6" UNIQUE CONSTRAINT, btree (username)
Referenced by:
    TABLE "user_roles" CONSTRAINT "fkhfh9dx7w3ubf1co1vdev94g3f" FOREIGN KEY (user_id) REFERENCES users(id)


\d roles;
                                Table "public.roles"
 Column |         Type          |                     Modifiers
--------+-----------------------+----------------------------------------------------
 id     | integer               | not null default nextval('roles_id_seq'::regclass)
 name   | character varying(20) |
Indexes:
    "roles_pkey" PRIMARY KEY, btree (id)
Referenced by:
    TABLE "user_roles" CONSTRAINT "fkh8ciramu9cc9q3qcqiv4ue8a6" FOREIGN KEY (role_id) REFERENCES roles(id)


\d user_roles
   Table "public.user_roles"
 Column  |  Type   | Modifiers
---------+---------+-----------
 user_id | bigint  | not null
 role_id | integer | not null
Indexes:
    "user_roles_pkey" PRIMARY KEY, btree (user_id, role_id)
Foreign-key constraints:
    "fkh8ciramu9cc9q3qcqiv4ue8a6" FOREIGN KEY (role_id) REFERENCES roles(id)
    "fkhfh9dx7w3ubf1co1vdev94g3f" FOREIGN KEY (user_id) REFERENCES users(id)

We also need to add some rows into roles table before assigning any role to User.
Run following SQL insert statements:

INSERT INTO roles(name) VALUES('ROLE_USER');
INSERT INTO roles(name) VALUES('ROLE_MODERATOR');
INSERT INTO roles(name) VALUES('ROLE_ADMIN');

Then check the tables:

> SELECT * FROM roles;

 id |      name
----+----------------
  1 | ROLE_USER
  2 | ROLE_MODERATOR
  3 | ROLE_ADMIN
(3 rows)

Register some users with /signup API:

  • admin with ROLE_ADMIN
  • mod with ROLE_MODERATOR and ROLE_USER
  • zkoder with ROLE_USER

spring-boot-authentication-jwt-spring-security-signup-mod

Our tables after signup could look like this.

> SELECT * FROM users;

 id |       email        |                           password                           | username
----+--------------------+--------------------------------------------------------------+----------
  1 | admin@bezkoder.com | $2a$10$4K8Vq5mw.nwxl.WRmuYCfevme82c73uGkEcnPbmm/3/YJ3UToie7m | admin
  2 | mod@bezkoder.com   | $2a$10$1dCKuQoQqbBNCK.Rb8XQSemwqdHdVAcCTb1kUQLg2key/4VX./TvS | mod
  3 | user@bezkoder.com  | $2a$10$e9Mgd/63paPL0VBj232BH.tQvIgQu0/tBg/rwfyDVMUcQc8djEPle | zkoder
(3 rows)


> SELECT * FROM roles;

 id |      name
----+----------------
  1 | ROLE_USER
  2 | ROLE_MODERATOR
  3 | ROLE_ADMIN
(3 rows)


>SELECT * FROM user_roles;

 user_id | role_id
---------+---------
       1 |       3
       2 |       1
       2 |       2
       3 |       1
(4 rows)

Access public resource: GET /api/test/all

spring-boot-authentication-jwt-spring-security-get-public-resource

Access protected resource: GET /api/test/user

spring-boot-authentication-jwt-spring-security-get-user-resource-unauthorized

Login an account: POST /api/auth/signin

spring-boot-authentication-jwt-spring-security-login-mod

Access ROLE_USER resource: GET /api/test/user

spring-boot-authentication-jwt-spring-security-get-user-resource

Access ROLE_MODERATOR resource: GET /api/test/mod

spring-boot-authentication-jwt-spring-security-get-mod-resource

Access ROLE_ADMIN resource: GET /api/test/admin

spring-boot-authentication-jwt-spring-security-get-admin-resource-unauthorized

Conclusion

Congratulation!

Today we’ve learned so many interesting things about Spring Security and JWT Authentication in just a Spring Boot example.
Despite we wrote a lot of code, I hope you will understand the overall architecture of the application, and apply it in your project at ease.

Happy learning! See you again.

Source Code

You can find the complete source code for this tutorial on Github.

Further Reading

10 thoughts to “Secure Spring Boot App with Spring Security & JWT Authentication”

  1. Hello, im a french dev student, thank you very much for your work! I have a probleme with this method in UserDetailsImpl.

    => public static UserDetailsImpl build(User user) {
    		List authorities = user.getRoles().stream()
    				.map(role -> new SimpleGrantedAuthority(role.getName().name()))
    				.collect(Collectors.toList());
    
    		return new UserDetailsImpl(
    				user.getId(), 
    				user.getUsername(), 
    				user.getEmail(),
    				user.getPassword(), 
    				authorities);
    	}
    =>  getName() "cannot resolve method"
    

    Im not very strong with stream map etc, can you explain me this block a bit more?

    Thank you for your attention and continue to display this wonderful content.

    Mathieu

    1. Hi Mathieu,

      user.getRoles() returns a Set<Role>, we convert this Set to a Stream of Role. Imagine that the stream is a collection of Role that releases items in turn.

      map() changes every Role item above to a SimpleGrantedAuthority object, the parameter for the constructor could be one of these Strings: ‘ROLE_USER’, ‘ROLE_MODERATOR’, ‘ROLE_ADMIN’.

      So, what does role.getName().name() do?
      role.getName() returns ERole enum object, let’s call it erole_object. Look back to this:

      public enum ERole {
      	ROLE_USER,
          ROLE_MODERATOR,
          ROLE_ADMIN
      }
      

      erole_object.name() returns the String corresponding to the enum (‘ROLE_MODERATOR’ for example).

      Please make sure that you define Role model in Role.java correctly.

      Regards,
      bezkoder.

      1. Thank you a lot for your explanation! I will follow your site and youtube channel studiously and recommend it to others students!

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