spring5_demo1/spring5-auth/spring5-auth-client/src/main/java/com/yaozhitech/spring5/utils/JwtUtils.java

package com.yaozhitech.spring5.utils;

import java.io.UnsupportedEncodingException;
import java.util.Calendar;
import java.util.Date;
import java.util.Map;

import com.auth0.jwt.JWT;
import com.auth0.jwt.JWTVerifier;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.exceptions.JWTDecodeException;
import com.auth0.jwt.interfaces.Claim;
import com.auth0.jwt.interfaces.DecodedJWT;
import com.yaozhitech.spring5.common.util.UUIDUtils;

import lombok.extern.slf4j.Slf4j;

@Slf4j
public class JwtUtils {

	/**
     * 获得token中的信息无需secret解密也能获得
     * @return token中包含的签发时间
     */
    public static Date getIssuedAt(String token) {
        try {
            DecodedJWT jwt = JWT.decode(token);
            return jwt.getIssuedAt();
        } catch (JWTDecodeException e) {
        	log.error(e.getMessage(), e);
            return null;
        }
    }

    /**
     * 获得token中的信息无需secret解密也能获得
     * @return token中包含的用户名
     */
    public static String getUsername(String token) {
        try {
            DecodedJWT jwt = JWT.decode(token);
            return jwt.getClaim("username").asString();
        } catch (JWTDecodeException e) {
        	log.error(e.getMessage(), e);
            return null;
        }
    }
    
    /**
     * 需要密钥才能获得信息
     */
    public static Map<String, Claim> verifyToken(String token, String secret) {
        DecodedJWT jwt = null;
        try {
            JWTVerifier verifier = JWT.require(Algorithm.HMAC256(secret)).build();
            jwt = verifier.verify(token);
        } catch (Exception e) {
        	log.error(e.getMessage(), e);
            return null;
        }
        return jwt.getClaims();
    }
    
    public static String verifyTokenAndGet(String token, String secret) {
        DecodedJWT jwt = null;
        try {
            JWTVerifier verifier = JWT.require(Algorithm.HMAC256(secret)).build();
            jwt = verifier.verify(token);
        } catch (Exception e) {
        	log.error(e.getMessage(), e);
            return null;
        }
        return jwt.getClaim("username").asString();
    }

    /**
     * 生成签名,expireTime后过期
     * @param username 用户名
     * @param time 过期时间s
     * @return 加密的token
     */
    public static String sign(String username, String salt, long time) {
        try {
            Date date = new Date(System.currentTimeMillis()+time*1000);
            Algorithm algorithm = Algorithm.HMAC256(salt);
            // 附带username信息
            return JWT.create()
                    .withClaim("username", username)
                    .withExpiresAt(date)
                    .withIssuedAt(new Date())
                    .sign(algorithm);
        } catch (UnsupportedEncodingException e) {
            return null;
        }
    }

    /**
     * token是否过期
     * @return true：过期
     */
    public static boolean isTokenExpired(String token) {
        Date now = Calendar.getInstance().getTime();
        DecodedJWT jwt = JWT.decode(token);
        return jwt.getExpiresAt().before(now);
    }

    /**
     * 生成随机盐,长度32位
     * @return
     */
    public static String generateSalt(){
        return UUIDUtils.generateShortUuid();
    }
}