Jwt 工具类

import io.jsonwebtoken.*;

import javax.crypto.SecretKey;

import javax.crypto.spec.SecretKeySpec;

import java.util.Base64;

import java.util.Date;

import java.util.UUID;

public class JWTHelper {

    // 设置有效期 一个小时

    public static final Long JWT_TTL = 60 * 60 * 1000L;

    // 设置密钥 设置长度不能大于 11

    public static final String JWT_KEY = "liusangbaoyo";

    public static String getUUID() {

        return UUID.randomUUID().toString().replaceAll("-", "");

    }

    /**

     * 生成 JWT

     *

     * @param subject token 中要存放的数据 (JSON 格式)

     * @return

     */

    public static String createJwt(String subject) {

        return getJwtBuilder(subject, null, getUUID(), null, null).compact();

    }

    public static String createJwt(Long id, String name) {

        return getJwtBuilder(null, null, getUUID(), id, name).compact();

    }

    public static String createJwt(String subject, Long ttlMillis) {

        // 设置过期时间

        return getJwtBuilder(subject, ttlMillis, getUUID(), null, null).compact();

    }

    private static JwtBuilder getJwtBuilder(String subject, Long ttlMillis, String uuid, Long id, String name) {

        SignatureAlgorithm signatureAlgorithm = SignatureAlgorithm.HS256;

        SecretKey secretKey = generalKey();

        long nowMillis = System.currentTimeMillis();

        Date now = new Date(nowMillis);

        if (ttlMillis == null) {

            ttlMillis = JWTHelper.JWT_TTL;

        }

        long expMills = nowMillis + ttlMillis;

        Date expDate = new Date(expMills);

        return Jwts.builder()

                .setId(uuid) // 唯一的 ID

                .setSubject(subject) // 主题，可以是 JSON 数据

                .claim("userId", id)

                .claim("username", name)

                .setIssuer("dkx") // 签发者

                .setIssuedAt(now) // 签发时间

                .signWith(signatureAlgorithm, secretKey) // 使用 HS256 对称加密算法签名，第二个参数为密钥

                .setExpiration(expDate);

    }

    public static String createJwt(String id, String subject, Long ttlMillis) {

        return getJwtBuilder(subject, ttlMillis, id, null, null).compact();

    }

    private static SecretKey generalKey() {

        byte[] encodedKey = Base64.getDecoder().decode(JWTHelper.JWT_KEY);

        return new SecretKeySpec(encodedKey, 0, encodedKey.length, "AES");

    }

    public static Claims parseJwt(String jwt) {

        Claims claims;

        SecretKey secretKey = generalKey();

        try {

            return Jwts.parser()

                    .setSigningKey(secretKey)

                    .parseClaimsJws(jwt)

                    .getBody();

        } catch (ExpiredJwtException e) {

            claims = e.getClaims();

        }

        return claims;

    }

}