How do I implement JWT in a Java application?

How do I implement JWT in a Java application?

To implement JWT in a Java application, you can use libraries like jjwt or Java JWT. Would you like a code example?

Yes, please provide a code example using jjwt.

Sure! Here's a simple example:

import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;

public class JwtUtil {
    private String secretKey = "your_secret_key";

    public String generateToken(String username) {
        return Jwts.builder()
                .setSubject(username)
                .setIssuedAt(new Date())
                .setExpiration(new Date(System.currentTimeMillis() + 1000 * 60 * 60 * 10))
                .signWith(SignatureAlgorithm.HS256, secretKey)
                .compact();
    }
}

This code generates a JWT token for a given username.

How do I validate the JWT token?

You can validate the JWT token by parsing it and checking its signature. Here's an example:

public Claims validateToken(String token) {
    return Jwts.parser()
            .setSigningKey(secretKey)
            .parseClaimsJws(token)
            .getBody();
}

What are the common use cases for JWT?

Common use cases for JWT include authentication, information exchange, and securing APIs.