依赖

 implementation 'com.auth0:java-jwt:3.4.0'

工具类

package com.solargrids.energymonitor.utils;

import com.auth0.jwt.JWT;
import com.auth0.jwt.JWTCreator;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.exceptions.JWTDecodeException;
import com.auth0.jwt.interfaces.DecodedJWT;
import org.apache.commons.lang3.StringUtils;

import java.util.Calendar;
import java.util.Map;

/**
 * @author 1065246
 * @description:
 * @createTime:2023/3/2 13:35
 */
public class JWTUtil {
    /**
     * 签名秘钥 此签名为 pwd的sha256大写
     * SecureUtil.sha256("pwd").toUpperCase()
     */
    private static final String SIGN_KEY = "7D5703BFD49B6CFE16F79A8A8F539DC5E2C3A8E203F00C09538E47AE26F8B03D";

    /**
     * 默认的过期时间:分钟
     */
    private static final Integer DEFAULT_EXPIRES = 60 * 60;

    /**
     * token默认的长度
     */
    private static final Integer DEFAULT_TOKEN_SIZE = 3;

    /**
     * 生成令牌
     *
     * @param payload     数据正文
     * @param expires 过期时间，单位(秒)
     */
    public static String getToken(Map<String, String> payload, Integer expires) throws Exception {
        //创建日历
        Calendar instance = Calendar.getInstance();
        //设置过期时间
        instance.add(Calendar.SECOND, expires);

        //创建jwt builder对象
        JWTCreator.Builder builder = JWT.create();

        //payload
        payload.forEach((k, v) -> {builder.withClaim(k, v);});

        //指定过期时间
        String token = builder.withExpiresAt(instance.getTime())//设置加密方式
                .sign(Algorithm.HMAC256(SIGN_KEY));
        //返回tokean
        return confoundPayload(token);
    }

   public static DecodedJWT verify(String token) throws TokenAuthenticationException {
        try {
            //解析token
            String dToken = deConfoundPayload(token);
            //创建返回结果
            return JWT.require(Algorithm.HMAC256(SIGN_KEY)).build().verify(dToken);
        } catch (JWTDecodeException jwtDecodeException) {
            throw new TokenAuthenticationException(ResultEnum.TOKEN_INVALID);
        } catch (SignatureVerificationException signatureVerificationException) {
            throw new TokenAuthenticationException(ResultEnum.TOKEN_SIGNATURE_INVALID);
        } catch (TokenExpiredException tokenExpiredException) {
            throw new TokenAuthenticationException(ResultEnum.TOKEN_EXPIRED);
        } catch (Exception ex) {
            throw new TokenAuthenticationException(ResultEnum.TOKEN_ERROR);
        }
    }


    /**
     * 对一个base64编码进行混淆  此处还可以进行replace混淆，考虑到效率问题，这里就不做啦~
     * 对于加密的思路还有位移、字符替换等~
     *
     * @param token 混淆payload前的token
     */
    private static String confoundPayload(String token) throws Exception {
        //分割token
        String[] split = token.split("\\.");
        //如果token不符合规范
        if (split.length != DEFAULT_TOKEN_SIZE) {
            throw new JWTDecodeException("签名不正确");
        }
        //取出payload
        String payload = split[1];
        //获取长度
        int length = payload.length() / 2;
        //指定截取点
        int index = payload.length() % 2 != 0 ? length + 1 : length;
        //混淆处理后的token
        return split[0] + "." + reversePayload(payload, index) + "." + split[2];
    }

    /**
     * 对一个混淆后的base编码进行解析
     * Authorization: Bearer <token>
     * @param token 混淆后的token
     */
    private static String deConfoundPayload(String token) throws Exception {
        if(StringUtils.isEmpty(token)){
            throw new JWTDecodeException("you have no permission with token,please login!");
        }
        //分割token
        String[] split = token.split("\\.");
        //如果token不符合规范
        if (split.length != DEFAULT_TOKEN_SIZE) {
            throw new JWTDecodeException("you token is valid");
        }
        //取出payload
        String payload = split[1];
        //返回解析后的token
        return split[0] + "." + reversePayload(payload, payload.length() / 2) + "." + split[2];
    }

    /**
     * 将md5编码位移
     *
     * @param payload payload编码
     * @param index   位移处
     */
    private static String reversePayload(String payload, Integer index) {
        return payload.substring(index) + payload.substring(0, index);
    }

}