Angular 12 + Spring Boot: JWT Authentication example | Spring Security

In this tutorial, I will show you how to build a full stack Angular 12 + Spring Boot JWT Authentication example. The back-end server uses Spring Boot with Spring Security for JWT Authentication & Role based Authorization, Spring Data JPA for interacting with database. The front-end will be built using Angular 12 with HttpInterceptor & Form validation.

Related Posts:
– Angular 12 + Spring Boot: CRUD example
– Angular 12 + Spring Boot: File upload example
– Spring Boot, MongoDB: JWT Authentication with Spring Security

Newer versions:
– Angular 13 + Spring Boot: JWT Authentication & Authorization example
– Angular 14 + Spring Boot: JWT Authentication & Authorization example
– Angular 15 + Spring Boot: JWT Authentication & Authorization example

JWT (JSON Web Token)

JWT is popular for Authentication and Information Exchange. Server encodes data into a JSON Web Token and send it to the Client. The Client saves the JWT, then every Request from Client to protected routes or resources should be attached that JWT (commonly at header). The Server will validate that JWT and return the Response.

The big advantage of JWT (Token-based Authentication) is that we store the Token on Client side: Local Storage for Browser, Keychain for IOS and SharedPreferences for Android… So we don’t need to build another backend project that supports Native Apps or an additional Authentication module for Native App users.

There are three important parts of a JWT: Header, Payload, Signature. Together they are combined to a standard structure: header.payload.signature.

The Client typically attact JWT in Authorization header with Bearer prefix:

Authorization: Bearer [header].[payload].[signature]

For more details, you can visit:
In-depth Introduction to JWT-JSON Web Token

Angular 12 Spring Boot Authentication example

It will be a full stack, with Spring Boot for back-end and Angular 12 for front-end. The system is secured by Spring Security with JWT Authentication.

• User can signup new account, login with username & password.
• Role based Authorization (admin, moderator, user)

Screenshots

Here are UI screenshots of our system.

– Anyone can access a public page before logging in:

– New user registration:

– Signup Form Validation:

More details about Form Validation at:
Angular 12 Form Validation example (Reactive Forms)

– After signup is successful, User can login:

-Loggedin User can access Profile page/ User page:

– This is UI for admin:

– If a User who doesn’t have Admin role tries to access Admin/Moderator Board page:

Demo

This is full Angular + Spring Boot JWT authentication demo (with form validation, check signup username/email duplicates, test authorization with 3 roles: Admin, Moderator, User).

In the video, we use Angular 10 for Client, but logic and UI are the same as this Angular version 12.

Flow for User Registration and User Login

The diagram shows flow for User Registration process and User Login process.

It’s not too difficult to understand. We have 2 endpoints for authentication:

• api/auth/signup for User Registration
• api/auth/signin for User Login

If Client wants to send request to protected data/endpoints, a legal JWT must be added to HTTP Authorization Header.

Spring Boot & Spring Security for Back-end

Overview

Our Spring Boot Application can be summarized in the diagram below:

Let me explain it.

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

To implement the server with concept above, we will use:
– Java 8
– Spring Boot 2 (with Spring Security, Spring Web, Spring Data)
– jjwt 0.9.1
– PostgreSQL/MySQL
– Maven 3.6.1

Project Structure

The structure of Spring Boot back-end project is pretty complicated:

You can see that there are 5 packages:

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).

Implementation

You can find step by step to implement this Spring Boot – Spring Security App in the post:
Secure Spring Boot App with Spring Security & JWT Authentication

For working with MongoDB:
Spring Boot, MongoDB: JWT Authentication with Spring Security

Or PostgreSQL:
Spring Boot, Spring Security, PostgreSQL: JWT Authentication example

Angular 12 for Front-end

Overview

Our Angular 12 App can be summarized in component diagram below:

Let’s try to understand it right now.

– The App component is a container using Router. It gets user token & user information from Browser Session Storage via token-storage.service. Then the navbar now can display based on the user login state & roles.

– Login & Register components have form for submission data (with support of Form Validation). They use token-storage.service for checking state and auth.service for sending signin/signup requests.

– auth.service uses Angular HttpClient ($http service) to make authentication requests.
– every HTTP request by $http service will be inspected and transformed before being sent by auth-interceptor.

– Home component is public for all visitor.

– Profile component get user data from Session Storage.

– BoardUser, BoardModerator, BoardAdmin components will be displayed depending on roles from Session Storage. In these components, we use user.service to get protected resources from API.

Technology

– Angular 12
– RxJS 6
– Bootstrap 4

Project Structure

This is the folder structure of our Angular front-end project:

You can understand it properly without any explanation because we’ve looked at the overview before.

Implementation

You can find step by step to implement this Angular 12 App in the post:
Angular 12 JWT Authentication example with Web Api

If you want to store JWT in HttpOnly Cookie, please visit:
Angular 12 JWT Authentication & Authorization with HttpOnly Cookie

Other versions:
– 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 13 JWT Authentication example with Web Api
– Angular 14 JWT Authentication example with Web Api
– Angular 15 JWT Authentication example with Web Api

Further Reading

• Spring Boot: Spring Security
• In-depth Introduction to JWT-JSON Web Token
• Spring Boot + Angular 12 CRUD example

Source Code

The complete source code for this tutorial can be found at Spring Boot + Angular Github.

Conclusion

Now we have an overview of Angular 12 Spring Boot Authentication and Role based Authorization example using JWT, Spring Security, Angular HttpInterceptor along with flow for signup/login actions.

We also take a look at Spring Boot server architecture for JWT Authentication using Spring Sercurity & Spring Data JPA, as well as Angular project structure for building a front-end app working with JWT.

Next tutorials will show you more details about how to implement this interesting system:
– Back-end:

• Using MySQL
• Using PostgreSQL
• Using MongoDB

– Front-end:

• Using Angular 8
• Using Angular 10
• Using Angular 11
• Using Angular 12
• Using Angular 13

You will want to know how to run both projects in one place:
How to Integrate Angular 12 with Spring Boot Rest API

Fullstack:
– Angular + Spring Boot + MySQL example
– Angular + Spring Boot + PostgreSQL example
– Angular + Spring Boot + MongoDB example
– Angular 12 + Spring Boot: File upload example

Newer versions:
– Angular 13 + Spring Boot: JWT Authentication & Authorization example
– Angular 14 + Spring Boot: JWT Authentication & Authorization example
– Angular 15 + Spring Boot: JWT Authentication & Authorization example

Happy learning, see you again!