JJWT是一个提供端到端的JWT创建和验证的Java库，永远免费和开源(Apache License，版本2.0)。JJW很容易使用和理解。它被设计成一个以建筑为中心的流畅界面，隐藏了它的大部分复杂性。

快速开始

引入依赖

  1.  <!--JWT依赖-->
  2. <dependency>
  3.     <groupId>io.jsonwebtoken</groupId>
  4.     <artifactId>jjwt</artifactId>
  5.     <version>0.9.1</version>
  6. </dependency>

创建token

  1. public class JwtdemoApplicationTests {
  3.     private static final String SECRETKEY="123123";
  5.     @Test
  6.     public void test() {
  7.         //创建一个JwtBuilder对象
  8.         JwtBuilder jwtBuilder = Jwts.builder()
  9.                 //声明的标识{"jti":"666"}
  10.                 .setId("666")
  11.                 //主体，用户{"sub":"Fox"}
  12.                 .setSubject("Fox")
  13.                 //创建日期{"ita":"xxxxxx"}
  14.                 .setIssuedAt(new Date())
  15.                 //设置过期时间   1分钟
  16.                 .setExpiration(new Date(System.currentTimeMillis()+60*1000))
  17.                 //claim可以存自己的一些信息
  18.                 //甚至可以直接传入map
  19.                 // .addClaims(map)
  20.                 .claim("roles","admin")
  21.                 .claim("logo","xxx.jpg")
  22.                 //签名手段，参数1：算法，参数2：盐
  23.                 .signWith(SignatureAlgorithm.HS256, SECRETKEY);
  24.         //获取token   jwt
  25.         String token = jwtBuilder.compact();
  26.         System.out.println(token);
  27.         // eyJhbGciOiJIUzI1NiJ9.eyJqdGkiOiI2NjYiLCJzdWIiOiJGb3giLCJpYXQiOjE2NDQyODY3MTYsImV4cCI6MTY0NDI4Njc3Niwicm9sZXMiOiJhZG1pbiIsImxvZ28iOiJ4eHguanBnIn0.dixD_GK5eYBXKdQDTQnwxn3i5TSoTp4SJvXKoqjdNVY
  29.         //三部分的base64解密
  30.         System.out.println("=========");
  31.         String[] split = token.split("\\.");
  32.         System.out.println(Base64Codec.BASE64.decodeToString(split[0]));
  33.         // {"alg":"HS256"}
  34.         System.out.println(Base64Codec.BASE64.decodeToString(split[1]));
  35.         // {"jti":"666","sub":"Fox","iat":1644286716,"exp":1644286776,"roles":"admin","logo":"xxx.jpg
  36.         //base64无法解密,所以输出的是乱码,无法解析的原因是为了安全性保证
  37.         System.out.println(Base64Codec.BASE64.decodeToString(split[2]));
  38.         // v,C�^`�u �B|1�x�M*����r��7M
  39.     }
  40. }

输出结果:

  1. eyJhbGciOiJIUzI1NiJ9.eyJqdGkiOiI2NjYiLCJzdWIiOiJGb3giLCJpYXQiOjE2NDQyODc0NDIsImV4cCI6MTY0NDI4NzUwMiwicm9sZXMiOiJhZG1pbiIsImxvZ28iOiJ4eHguanBnIn0.veExdFdoZpHSXLSs1leQDPHx0dHt-ILLfDeilWucf7U
  2. =========
  3. {"alg":"HS256"}
  4. {"jti":"666","sub":"Fox","iat":1644287442,"exp":1644287502,"roles":"admin","logo":"xxx.jpg
  5. �Z�

token的验证解析

  1. public class JwtdemoApplicationTests {
  3.     private static final String SECRETKEY="123123";
  5.     @Test
  6.     public void testParseToken(){
  7.         //token
  8.         String token ="eyJhbGciOiJIUzI1NiJ9.eyJqdGkiOiI2NjYiLCJzdWIiOiJGb3giLCJpYXQiOjE2NDQyODcwNjEsImV4cCI6MTY0NDI4NzEyMSwicm9sZXMiOiJhZG1pbiIsImxvZ28iOiJ4eHguanBnIn0.5tqXl0BvW_mUwizRTnCAZSulDEhZWypyzzvIc-o_zBM";
  9.         //解析token获取载荷中的声明对象
  10.         Claims claims = Jwts.parser()
  11.                 .setSigningKey(SECRETKEY)
  12.                 .parseClaimsJws(token)
  13.                 .getBody();
  14.         //如果token过期的话,就会抛异常出来
  15.         System.out.println("id:"+claims.getId());
  16.         System.out.println("subject:"+claims.getSubject());
  17.         System.out.println("issuedAt:"+claims.getIssuedAt());
  19.         DateFormat sf =new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
  20.         System.out.println("签发时间:"+sf.format(claims.getIssuedAt()));
  21.         System.out.println("过期时间:"+sf.format(claims.getExpiration()));
  22.         System.out.println("当前时间:"+sf.format(new Date()));
  24.         System.out.println("roles:"+claims.get("roles"));
  25.         System.out.println("logo:"+claims.get("logo"));
  26.     }
  28. }

如果token没过期的话输出结果:

  1. id:666
  2. subject:Fox
  3. issuedAt:Tue Feb 08 10:30:42 CST 2022
  4. 签发时间:2022-02-08 10:30:42
  5. 过期时间:2022-02-08 10:31:42
  6. 当前时间:2022-02-08 10:31:09
  7. roles:admin
  8. logo:xxx.jpg

如果token已经过期的话输出结果:

  1. io.jsonwebtoken.ExpiredJwtException: JWT expired at 2022-02-08T10:31:42Z. Current time: 2022-02-08T10:31:57Z, a difference of 15635 milliseconds.  Allowed clock skew: 0 milliseconds.