Spring Boot and JSON Web Tokens (JWT) together provide a robust solution for token-based authentication. JWT is a compact, URL-safe means of representing claims to be transferred between two parties. In this guide, we'll explore how to implement token-based authentication with JWT in a Spring Boot application, understand how it works, and provide sample code with explanations for its implementation.

Understanding JWT-Based Authentication

JWT is a self-contained token that can securely transmit information between parties as a JSON object. It is commonly used for authentication and authorization in web applications. JWTs consist of three parts: a header, payload, and signature. They are typically used as bearer tokens, which are included in the request headers for authentication.

Key Components of JWT-Based Authentication

Implementing JWT-based authentication in Spring Boot involves the following key components:

  • JWT Library: Include a JWT library, such as jjwt, to handle JWT generation and parsing.
  • Security Configuration: Configure security rules in your Spring Boot application to validate JWTs and authenticate users.
  • Authentication Filter: Implement a custom authentication filter to extract and verify JWTs from incoming requests.
  • User Details Service: Define a user details service to load user information from your data source.

Implementing JWT-Based Authentication

To implement token-based authentication with JWT in Spring Boot, follow these steps:

  1. Add the necessary dependencies to your project's pom.xml (Maven) or build.gradle (Gradle) file:
<!-- Maven -->
// Gradle
dependencies {
implementation 'io.jsonwebtoken:jjwt:0.9.1'
  1. Create a class that defines your JWT security configuration:
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
public class SecurityConfig extends WebSecurityConfigurerAdapter {
protected void configure(HttpSecurity http) throws Exception {
.addFilterBefore(new JwtAuthenticationFilter(), UsernamePasswordAuthenticationFilter.class)
public UserDetailsService userDetailsService() {
PasswordEncoder encoder = PasswordEncoderFactories.createDelegatingPasswordEncoder();
UserDetails user = User.builder()
return new InMemoryUserDetailsManager(user);

In this example, we configure a basic security setup where URLs under "/public" are accessible without authentication, and all other URLs require authentication with a JWT token. You can replace the user details service and add JWT token handling as needed.


Implementing token-based authentication with JWT in Spring Boot is a secure and efficient way to protect your applications and APIs. This guide introduced JWT-based authentication, its components, and provided sample code for its implementation. As you further explore token-based authentication, you'll find that it's a powerful solution for securing your Spring Boot applications.