java jwt 工具类

以下是一个使用Java JWT工具类的示例：

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

import java.util.Date;
import java.util.HashMap;
import java.util.Map;

public class JwtUtils {
    private static final String SECRET_KEY = "your-secret-key";
    private static final long EXPIRATION_TIME = 3 * 1000L; // 3秒

    public static String createJwt(Map<String, Object> claims) {
        Date now = new Date();
        Date expiration = new Date(now.getTime() + EXPIRATION_TIME);

        return Jwts.builder()
                .setClaims(claims)
                .setIssuedAt(now)
                .setExpiration(expiration)
                .signWith(SignatureAlgorithm.HS256, SECRET_KEY)
                .compact();
    }

    public static Claims parseJwt(String jwt) {
        return Jwts.parser()
                .setSigningKey(SECRET_KEY)
                .parseClaimsJws(jwt)
                .getBody();
    }
}

public class Main {
    public static void main(String[] args) {
        // 创建JWT
        Map<String, Object> claims = new HashMap<>();
        claims.put("username", "zss");
        String jwt = JwtUtils.createJwt(claims);
        System.out.println(jwt);

        // 解析JWT
        Claims parseJwt = JwtUtils.parseJwt(jwt);
        Date issuedAt = parseJwt.getIssuedAt();
        Date expiration = parseJwt.getExpiration();
        System.out.println("令牌签发时间：" + issuedAt);
        System.out.println("令牌过期时间：" + expiration);
    }
}