How can I implement JWT authentication in a Spring Boot application?

How can I implement JWT authentication in a Spring Boot application?

To implement JWT authentication in Spring Boot, you need to set up a security configuration, create a JWT utility class, and define authentication and authorization filters.

What dependencies do I need to add to my Maven project?

You will need to add dependencies for Spring Security, JWT, and possibly Spring Web. Here's an example:

<dependency>
    <groupId>io.jsonwebtoken</groupId>
    <artifactId>jjwt</artifactId>
    <version>0.9.1</version>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-security</artifactId>
</dependency>

How do I generate a JWT token after user login?

After validating the user's credentials, you can create a JWT token using the JJWT library. Here's a simple example:

String token = Jwts.builder()
    .setSubject(username)
    .setExpiration(new Date(System.currentTimeMillis() + EXPIRATION_TIME))
    .signWith(SignatureAlgorithm.HS512, SECRET_KEY)
    .compact();

Can you explain how to secure my endpoints with JWT?

To secure your endpoints, you can use the @PreAuthorize annotation or configure your security filter chain to check for the JWT token in the request headers.