Spring Boot, Spring Security, PostgreSQL: JWT Authentication example

In this tutorial, we’re gonna build a Spring Boot JWT Authentication with Spring Security & PostgreSQL Application that supports Token based Authentication & Role based Authorization. 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 Database

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

Related Posts:
– Spring Boot Refresh Token with JWT example
– Spring Boot, PostgreSQL: CRUD example with Spring JPA
– Spring Boot Unit Test for JPA Repository
– Spring Boot Unit Test for Rest Controller
– @RestControllerAdvice example in Spring Boot
– Documentation: Spring Boot Swagger 3 example
– Caching: Spring Boot Redis Cache example
– Spring Boot custom Validation example

Fullstack:

• Spring Boot + Vuejs: JWT Authentication Example
• Spring Boot + Angular 8: JWT Authentication Example
• Spring Boot + Angular 10: JWT Authentication Example
• Spring Boot + Angular 11: JWT Authentication example
• Spring Boot + Angular 12: JWT Authentication example
• Spring Boot + Angular 13: JWT Authentication example
• Spring Boot + Angular 14: JWT Authentication example
• Spring Boot + Angular 15: JWT Authentication example
• Spring Boot + Angular 16: JWT Authentication example
• Spring Boot + React.js: JWT Authentication example

Overview of Spring Boot JWT Authentication with PostgreSQL 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:

The database we will be PostgreSQL. We interact with the database by using Spring configuring 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.

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

If you want to store JWT in HttpOnly Cookie, kindly visit:
Spring Boot Login example with JWT HttpOnly Cookie

You will need to implement Refresh Token:

More details at: Spring Boot Refresh Token with JWT example

Spring Boot Server Architecture with Spring Security

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

Now I will explain it briefly.

Spring Security

– WebSecurityConfig is the crux of our security implementation. It configures cors, csrf, session management, rules for protected resources. We can also extend and customize the default configuration that contains the elements below.
(WebSecurityConfigurerAdapter is deprecated from Spring 2.7.0, you can check the source code for update. More details at:
WebSecurityConfigurerAdapter Deprecated in Spring Boot)

– 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 authentication error.

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.

Understand the architecture deeply and grasp the overview more easier:
Spring Boot Architecture for JWT with Spring Security

Technology

• Java 17 / 11 / 8
• Spring Boot 3 / 2 (with Spring Security, Spring Web, Spring Data JPA)
• jjwt-api 0.11.5
• PostgreSQL
• Maven

Project Structure

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

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

• WebSecurityConfig

(WebSecurityConfigurerAdapter is deprecated from Spring 2.7.0, you can check the source code for update. More details at:
WebSecurityConfigurerAdapter Deprecated in Spring Boot)

• 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 PostgreSQL Database.

• UserRepository extends JpaRepository<User, Long>
• RoleRepository extends JpaRepository<Role, Long>

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-api</artifactId>
	<version>0.11.5</version>
</dependency>

<dependency>
	<groupId>io.jsonwebtoken</groupId>
	<artifactId>jjwt-impl</artifactId>
	<version>0.11.5</version>
	<scope>runtime</scope>
</dependency>

<dependency>
	<groupId>io.jsonwebtoken</groupId>
	<artifactId>jjwt-jackson</artifactId>
	<version>0.11.5</version>
	<scope>runtime</scope>
</dependency>

We also need to add one more dependency for PostgreSQL:

<dependency>
	<groupId>org.postgresql</groupId>
	<artifactId>postgresql</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:mysql://localhost:3306/testdb_spring?useSSL=false
spring.datasource.username=root
spring.datasource.password=123456

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

# App Properties
bezkoder.app.jwtSecret= ======================BezKoder=Spring===========================
bezkoder.app.jwtExpirationMs=86400000

• spring.datasource.username & spring.datasource.password properties are the same as your database installation.
• Spring Boot uses Hibernate for JPA implementation, we configure PostgreSQLDialect for PostgreSQL
• spring.jpa.hibernate.ddl-auto is used for database initialization. We set the value to update value so that a table will be created in the database automatically corresponding to defined data model. Any change to the model will also trigger an update to the table. For production, this property should be validate.

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.spring.security.postgresql.models;

public enum ERole {
  ROLE_USER,
  ROLE_MODERATOR,
  ROLE_ADMIN
}

Role model in Role.java

package com.bezkoder.spring.security.postgresql.models;

import jakarta.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;
  }

  // getters and setters
}

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

package com.bezkoder.spring.security.postgresql.models;

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

import jakarta.persistence.*;
import jakarta.validation.constraints.Email;
import jakarta.validation.constraints.NotBlank;
import jakarta.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<Role> roles = new HashSet<>();

  public User() {
  }

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

  // getters and setters
}

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.spring.security.postgresql.repository;

import java.util.Optional;

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

import com.bezkoder.spring.security.postgresql.models.User;

@Repository
public interface UserRepository extends JpaRepository<User, Long> {
  Optional<User> 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.spring.security.postgresql.repository;

import java.util.Optional;

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

import com.bezkoder.spring.security.postgresql.models.ERole;
import com.bezkoder.spring.security.postgresql.models.Role;

@Repository
public interface RoleRepository extends JpaRepository<Role, Long> {
  Optional<Role> findByName(ERole name);
}

Configure Spring Security

Without WebSecurityConfigurerAdapter

WebSecurityConfigurerAdapter is deprecated from Spring 2.7.0. More details at:
WebSecurityConfigurerAdapter Deprecated in Spring Boot.

In security package, create WebSecurityConfig class.

WebSecurityConfig.java

package com.bezkoder.spring.security.postgresql.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.authentication.dao.DaoAuthenticationProvider;
import org.springframework.security.config.annotation.authentication.configuration.AuthenticationConfiguration;
import org.springframework.security.config.annotation.method.configuration.EnableMethodSecurity;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
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.SecurityFilterChain;
import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;

import com.bezkoder.spring.security.postgresql.security.jwt.AuthEntryPointJwt;
import com.bezkoder.spring.security.postgresql.security.jwt.AuthTokenFilter;
import com.bezkoder.spring.security.postgresql.security.services.UserDetailsServiceImpl;

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

  @Autowired
  private AuthEntryPointJwt unauthorizedHandler;

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

  @Bean
  public DaoAuthenticationProvider authenticationProvider() {
      DaoAuthenticationProvider authProvider = new DaoAuthenticationProvider();
       
      authProvider.setUserDetailsService(userDetailsService);
      authProvider.setPasswordEncoder(passwordEncoder());
   
      return authProvider;
  }
 
  @Bean
  public AuthenticationManager authenticationManager(AuthenticationConfiguration authConfig) throws Exception {
    return authConfig.getAuthenticationManager();
  }

  @Bean
  public PasswordEncoder passwordEncoder() {
    return new BCryptPasswordEncoder();
  }
  
  @Bean
  public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
    http.csrf(csrf -> csrf.disable())
        .exceptionHandling(exception -> exception.authenticationEntryPoint(unauthorizedHandler))
        .sessionManagement(session -> session.sessionCreationPolicy(SessionCreationPolicy.STATELESS))
        .authorizeHttpRequests(auth -> 
          auth.requestMatchers("/api/auth/**").permitAll()
              .requestMatchers("/api/test/**").permitAll()
              .anyRequest().authenticated()
        );
    
    http.authenticationProvider(authenticationProvider());

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

With WebSecurityConfigurerAdapter

In security package, create WebSecurityConfig class that extends WebSecurityConfigurerAdapter.

WebSecurityConfig.java

package com.bezkoder.spring.security.postgresql.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.spring.security.postgresql.security.jwt.AuthEntryPointJwt;
import com.bezkoder.spring.security.postgresql.security.jwt.AuthTokenFilter;
import com.bezkoder.spring.security.postgresql.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.

*For Spring Boot 2: @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.

– @EnableGlobalMethodSecurity is deprecated in Spring Boot 3. You can use @EnableMethodSecurity instead. For more details, please visit Method Security.

– 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.spring.security.postgresql.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.spring.security.postgresql.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<? extends GrantedAuthority> authorities;

  public UserDetailsImpl(Long id, String username, String email, String password,
      Collection<? extends GrantedAuthority> authorities) {
    this.id = id;
    this.username = username;
    this.email = email;
    this.password = password;
    this.authorities = authorities;
  }

  public static UserDetailsImpl build(User user) {
    List<GrantedAuthority> 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<? extends GrantedAuthority> 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/UserDetailsServiceImpl.java

package com.bezkoder.spring.security.postgresql.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.spring.security.postgresql.models.User;
import com.bezkoder.spring.security.postgresql.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.spring.security.postgresql.security.jwt;

import java.io.IOException;

import jakarta.servlet.FilterChain;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.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.spring.security.postgresql.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.spring.security.postgresql.security.jwt;

import java.security.Key;
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.spring.security.postgresql.security.services.UserDetailsImpl;

import io.jsonwebtoken.*;
import io.jsonwebtoken.io.Decoders;
import io.jsonwebtoken.security.Keys;

@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(key(), SignatureAlgorithm.HS256)
        .compact();
  }
  
  private Key key() {
    return Keys.hmacShaKeyFor(Decoders.BASE64.decode(jwtSecret));
  }

  public String getUserNameFromJwtToken(String token) {
    return Jwts.parserBuilder().setSigningKey(key()).build()
               .parseClaimsJws(token).getBody().getSubject();
  }

  public boolean validateJwtToken(String authToken) {
    try {
      Jwts.parserBuilder().setSigningKey(key()).build().parse(authToken);
      return true;
    } 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, and jwtSecret has 64 characters.

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.spring.security.postgresql.security.jwt;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

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

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

import com.fasterxml.jackson.databind.ObjectMapper;

@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.

If you want to customize the response data, just use an ObjectMapper like following code:

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

  response.setContentType(MediaType.APPLICATION_JSON_VALUE);
  response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);

  final Map<String, Object> body = new HashMap<>();
  body.put("status", HttpServletResponse.SC_UNAUTHORIZED);
  body.put("error", "Unauthorized");
  body.put("message", authException.getMessage());
  body.put("path", request.getServletPath());

  final ObjectMapper mapper = new ObjectMapper();
  mapper.writeValue(response.getOutputStream(), body);
}

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.spring.security.postgresql.controllers;

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

import jakarta.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.spring.security.postgresql.models.ERole;
import com.bezkoder.spring.security.postgresql.models.Role;
import com.bezkoder.spring.security.postgresql.models.User;
import com.bezkoder.spring.security.postgresql.payload.request.LoginRequest;
import com.bezkoder.spring.security.postgresql.payload.request.SignupRequest;
import com.bezkoder.spring.security.postgresql.payload.response.JwtResponse;
import com.bezkoder.spring.security.postgresql.payload.response.MessageResponse;
import com.bezkoder.spring.security.postgresql.repository.RoleRepository;
import com.bezkoder.spring.security.postgresql.repository.UserRepository;
import com.bezkoder.spring.security.postgresql.security.jwt.JwtUtils;
import com.bezkoder.spring.security.postgresql.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<String> 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<String> strRoles = signUpRequest.getRole();
    Set<Role> 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) (or @EnableMethodSecurity for Spring Boot 3) in WebSecurityConfig class?

@Configuration
// @EnableWebSecurity
// @EnableGlobalMethodSecurity(prePostEnabled = true)
@EnableMethodSecurity // Spring Boot 3
public class WebSecurityConfig extends WebSecurityConfigurerAdapter { ... }

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

controllers/TestController.java

package com.bezkoder.spring.security.postgresql.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

Our tables after signup could look like this.

> SELECT * FROM users;

 id |       email        |                           password                           | username
----+--------------------+--------------------------------------------------------------+----------
  1 | [email protected] | $2a$10$4K8Vq5mw.nwxl.WRmuYCfevme82c73uGkEcnPbmm/3/YJ3UToie7m | admin
  2 | [email protected]   | $2a$10$1dCKuQoQqbBNCK.Rb8XQSemwqdHdVAcCTb1kUQLg2key/4VX./TvS | mod
  3 | [email protected]  | $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

Access protected resource: GET /api/test/user

Login an account: POST /api/auth/signin

Access ROLE_USER resource: GET /api/test/user

Access ROLE_MODERATOR resource: GET /api/test/mod

Access ROLE_ADMIN resource: GET /api/test/admin

Solve Problem: javax.validation cannot be resolved

For Spring Boot 2.3 and later, you can see the compile error:
The import javax.validation cannot be resolved

It is because Validation Starter no longer included in web starters. So you need to add the starter yourself.
– For Maven:

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

– For Gradle:

dependencies {
  ...
  implementation 'org.springframework.boot:spring-boot-starter-validation'
}

Solve Problem with JDK 14

If you run this Spring Boot App with JDK 14 and get following error when trying to authenticate:

FilterChain java.lang.NoClassDefFoundError: javax/xml/bind/DatatypeConverter

Just add following dependency to pom.xml:

<dependency>
    <groupId>jakarta.xml.bind</groupId>
    <artifactId>jakarta.xml.bind-api</artifactId>
    <version>2.3.2</version>
</dependency>

Everything’s gonna work fine.

Conclusion

Congratulation!

Today we’ve learned so many interesting things about Spring Boot PostgreSQL Authentication with Spring Security and JWT – Token based Authentication. 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.

For understanding the architecture deeply and grasp the overview more easier:
Spring Boot Architecture for JWT with Spring Security

You should continue to implement Refresh Token:
Spring Boot Refresh Token with JWT example

You can also know how to deploy Spring Boot App on AWS (for free) with this tutorial.

Happy learning! See you again.

Further Reading

• Spring Security Reference
• In-depth Introduction to JWT-JSON Web Token
• Spring Boot Pagination & Filter example | Spring JPA, Pageable

Fullstack CRUD App:
– Spring Boot + Vue.js example
– Angular 8 + Spring Boot + PostgreSQL example
– Angular 10 + Spring Boot + PostgreSQL example
– Angular 11 + Spring Boot + PostgreSQL example
– Angular 12 + Spring Boot + PostgreSQL example
– Angular 13 + Spring Boot + PostgreSQL example
– Angular 14 + Spring Boot + PostgreSQL example
– Angular 15 + Spring Boot + PostgreSQL example
– Angular 16 + Spring Boot + PostgreSQL example
– Spring Boot + React + PostgreSQL example

Associations:
– JPA One To One example with Hibernate in Spring Boot
– JPA One To Many example with Hibernate and Spring Boot
– JPA Many to Many example with Hibernate in Spring Boot

Documentation: Spring Boot + Swagger 3 example (with OpenAPI 3)
Caching: Spring Boot Redis Cache example

Source Code

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

If you want to store JWT in HttpOnly Cookie, kindly visit:
Spring Boot Login example with JWT HttpOnly Cookie

Validate the signup request (password, confirm password):
Spring Boot custom Validation example