Spring Boot, MongoDB: JWT Authentication with Spring Security

This tutorial helps you build a Spring Boot Authentication (Login & Registration) & role-based Authorization example with JWT, Spring Security and Spring Data MongoDB. 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 MongoDB to interact with MongoDB Database

More Practice:
– Spring Boot JWT Authentication with Spring Security, Spring JPA
– Spring Boot + GraphQL + MongoDB example
– Spring Boot with MongoDB CRUD example using Spring Data
– Spring Boot Unit Test for Rest Controller
– @RestControllerAdvice example in Spring Boot
– Spring Boot, MongoDB, Reactive CRUD example
– Documentation: Spring Boot Swagger 3 example
– Caching: Spring Boot Redis Cache example
– Spring Boot custom Validation example
– Dockerize: Docker Compose: MongoDB and Spring Boot example

Spring Boot JWT Authentication with MongoDB example

Let’s me describe our Spring Boot application.

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

So we’re gonna provide APIs as following table:

– Spring Security will manage cors, csrf, session, rules for protected resources, authentication & authorization along with exception handler.
– The database we will use is MongoDB which can be accessed by the help of Spring Data MongoDB.

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.

This app can be used as a back-end that works well with these front-end applications (I’ve tested all of them):

• Vue.js JWT Authentication with Vuex and Vue Router
• Angular 8 JWT Authentication example with Web Api
• Angular 10 JWT Authentication example with Web Api
• Angular 11 JWT Authentication example with Web Api
• Angular 12 JWT Authentication example with Web Api
• Angular 13 JWT Authentication example with Web Api
• React JWT Authentication (without Redux) example
• React Hooks: JWT Authentication (without Redux) example
• React Redux: JWT Authentication example

You can use HttpOnly Cookie for this example instead.

You may 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:

Let me 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.

Technology

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

Project Structure

This is folders & files structure for our Spring Boot 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 MongoDB MongoRepository to interact with Database.

• UserRepository extends MongoRepository<User, String>
• RoleRepository extends MongoRepository<Role, String>

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 Data MongoDB 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-mongodb</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> 

Configure Spring Data MongoDB & App properties

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

spring.data.mongodb.database=bezkoder_db spring.data.mongodb.host=localhost spring.data.mongodb.port=27017 # App Properties bezkoder.app.jwtSecret= ======================BezKoder=Spring=========================== bezkoder.app.jwtExpirationMs= 86400000 

Create the models

We’re gonna have 2 collections in database: users & roles.

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

ERole enum in ERole.java. There are 3 roles corresponding to 3 enum.

package com.bezkoder.spring.jwt.mongodb.models; public enum ERole { ROLE_USER, ROLE_MODERATOR, ROLE_ADMIN } 

Role model in Role.java

package com.bezkoder.spring.jwt.mongodb.models; import org.springframework.data.annotation.Id; import org.springframework.data.mongodb.core.mapping.Document; @Document(collection = "roles") public class Role { @Id private String id; private ERole name; public Role() { } public Role(ERole name) { this.name = name; } public String getId() { return id; } public void setId(String id) { this.id = id; } public ERole getName() { return name; } public void setName(ERole name) { this.name = name; } } 

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

package com.bezkoder.spring.jwt.mongodb.models; import java.util.HashSet; import java.util.Set; import jakarta.validation.constraints.Email; import jakarta.validation.constraints.NotBlank; import jakarta.validation.constraints.Size; import org.springframework.data.annotation.Id; import org.springframework.data.mongodb.core.mapping.DBRef; import org.springframework.data.mongodb.core.mapping.Document; @Document(collection = "users") public class User { @Id private String id; @NotBlank @Size(max = 20) private String username; @NotBlank @Size(max = 50) @Email private String email; @NotBlank @Size(max = 120) private String password; @DBRef 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; } public String getId() { return id; } public void setId(String 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<Role> getRoles() { return roles; } public void setRoles(Set<Role> roles) { this.roles = roles; } } 

You can see that we annotate each model with @Document. The annotation specifies domain object to be persisted to MongoDB.

Implement Repositories

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

UserRepository

There are 3 necessary methods that MongoRepository supports.

package com.bezkoder.spring.jwt.mongodb.repository; import java.util.Optional; import org.springframework.data.mongodb.repository.MongoRepository; import com.bezkoder.spring.jwt.mongodb.models.User; public interface UserRepository extends MongoRepository<User, String> { Optional<User> findByUsername(String username); Boolean existsByUsername(String username); Boolean existsByEmail(String email); } 

RoleRepository

This repository also extends MongoRepository and provides a finder method.

package com.bezkoder.spring.jwt.mongodb.repository; import java.util.Optional; import org.springframework.data.mongodb.repository.MongoRepository; import com.bezkoder.spring.jwt.mongodb.models.ERole; import com.bezkoder.spring.jwt.mongodb.models.Role; public interface RoleRepository extends MongoRepository<Role, String> { 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.jwt.mongodb.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.jwt.mongodb.security.jwt.AuthEntryPointJwt; import com.bezkoder.spring.jwt.mongodb.security.jwt.AuthTokenFilter; import com.bezkoder.spring.jwt.mongodb.security.services.UserDetailsServiceImpl; @Configuration //@EnableWebSecurity @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.jwt.mongodb.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.jwt.mongodb.security.jwt.AuthEntryPointJwt; import com.bezkoder.spring.jwt.mongodb.security.jwt.AuthTokenFilter; import com.bezkoder.spring.jwt.mongodb.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); } } 

– @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.jwt.mongodb.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.jwt.mongodb.security.jwt.AuthEntryPointJwt; import com.bezkoder.spring.jwt.mongodb.security.jwt.AuthTokenFilter; import com.bezkoder.spring.jwt.mongodb.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); } } 

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.

UserDetailsService will be used for getting UserDetails object. You can look at UserDetailsService interface that has following method:

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

Now we implement it to override loadUserByUsername() method.

security/services/UserDetailsServiceImpl.java

package com.bezkoder.spring.jwt.mongodb.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.jwt.mongodb.models.User; import com.bezkoder.spring.jwt.mongodb.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.jwt.mongodb.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.jwt.mongodb.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.jwt.mongodb.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.jwt.mongodb.security.services.UserDetailsImpl; import com.bezkoder.spring.jwt.mongodb.security.jwt.JwtUtils; 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.jwt.mongodb.security.jwt; import java.io.IOException; 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.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 }

I don’t show these POJOs here for keeping the tutorial not so long,
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.jwt.mongodb.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.jwt.mongodb.models.ERole; import com.bezkoder.spring.jwt.mongodb.models.Role; import com.bezkoder.spring.jwt.mongodb.models.User; import com.bezkoder.spring.jwt.mongodb.payload.request.LoginRequest; import com.bezkoder.spring.jwt.mongodb.payload.request.SignupRequest; import com.bezkoder.spring.jwt.mongodb.payload.response.JwtResponse; import com.bezkoder.spring.jwt.mongodb.payload.response.MessageResponse; import com.bezkoder.spring.jwt.mongodb.repository.RoleRepository; import com.bezkoder.spring.jwt.mongodb.repository.UserRepository; import com.bezkoder.spring.jwt.mongodb.security.jwt.JwtUtils; import com.bezkoder.spring.jwt.mongodb.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.getRoles(); 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.jwt.mongodb.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

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

db.roles.insertMany([ { name: "ROLE_USER" }, { name: "ROLE_MODERATOR" }, { name: "ROLE_ADMIN" }, ]) 

Then check the MongoDB collections:

Register some users with /signup API:

• admin with ROLE_ADMIN
• moderator with ROLE_MODERATOR and ROLE_USER
• bezkoder with ROLE_USER

After make some user registration, users collection could look like this-

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' } 

Problem with newer JDK

If you run this Spring Boot App with JDK 9 or newer versions 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

Oh Yeah! Today we’ve learned many things about Spring Security and JWT Token based Authentication in a Spring Boot MongoDB login & registration example (with Authorization).

This app can be used as a back-end that works well with these front-end applications (I’ve tested all of them):

• Vue.js JWT Authentication with Vuex and Vue Router
• Angular 8 JWT Authentication example with Web Api
• Angular 10 JWT Authentication example with Web Api
• Angular 11 JWT Authentication example with Web Api
• Angular 12 JWT Authentication example with Web Api
• Angular 13 JWT Authentication example with Web Api
• React JWT Authentication (without Redux) example
• React Hooks: JWT Authentication (without Redux) example
• React Redux: JWT Authentication example

Happy learning! See you again.

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

Further Reading

• In-depth Introduction to JWT-JSON Web Token
• Spring Security Reference
• Spring Data MongoDB – Reference Documentation

Fullstack CRUD App:

• Angular 8 + Spring Boot + MongoDB example
• Angular 10 + Spring Boot + MongoDB example
• Angular 11 + Spring Boot + MongoDB example
• Angular 12 + Spring Boot + MongoDB example
• Angular 13 + Spring Boot + MongoDB example
• Angular 14 + Spring Boot + MongoDB example
• Angular 15 + Spring Boot + MongoDB example
• Angular 16 + Spring Boot + MongoDB example
• React + Spring Boot + MongoDB example
• Vue + Spring Boot + MongoDB example

Documentation: Spring Boot + Swagger 3 example (with OpenAPI 3)
Caching: Spring Boot Redis Cache example
Dockerize: Docker Compose: MongoDB and Spring Boot example

Source Code

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

You can also use HttpOnly Cookie for this example.

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