<dependencies>
    <!-- JWT -->
    <dependency>
        <groupId>io.jsonwebtoken</groupId>
        <artifactId>jjwt</artifactId>
        <version>0.7.0</version>
    </dependency>
    <!--junit-->
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
    </dependency>
</dependencies>

public class JwtTests {
    //过期时间，毫秒，24小时
    private static long tokenExpiration = 24*60*60*1000;
    //秘钥
    private static String tokenSignKey = "atguigu123";
    @Test
    public void testCreateToken(){
        String token = Jwts.builder()
                .setHeaderParam("typ", "JWT") //令牌类型
                .setHeaderParam("alg", "HS256") //签名算法
                .setSubject("guli-user") //令牌主题
                .setIssuer("atguigu")//签发者
                .setAudience("atguigu")//接收者
                .setIssuedAt(new Date())//签发时间
                .setExpiration(new Date(System.currentTimeMillis() + tokenExpiration)) //过期时间
                .setNotBefore(new Date(System.currentTimeMillis() + 20*1000)) //20秒后可用
                .setId(UUID.randomUUID().toString())
                .claim("nickname", "Helen")
                .claim("avatar", "1.jpg")
                .signWith(SignatureAlgorithm.HS256, tokenSignKey)//签名哈希
                .compact(); //转换成字符串
        System.out.println(token);
    }
}

  @Test
    public void testGetUserInfo(){
        String token = Jwts.builder()
                .setHeaderParam("typ", "JWT") //令牌类型
                .setHeaderParam("alg", "HS256") //签名算法
                .setSubject("guli-user") //令牌主题
                .setIssuer("atguigu")//签发者
                .setAudience("atguigu")//接收者
                .setIssuedAt(new Date())//签发时间
                .setExpiration(new Date(System.currentTimeMillis() + tokenExpiration)) //过期时间
                .setNotBefore(new Date(System.currentTimeMillis())) //20秒后可用
                .setId(UUID.randomUUID().toString())
                .claim("nickname", "Helen")
                .claim("avatar", "1.jpg")
                .signWith(SignatureAlgorithm.HS256, tockenSigKey)//签名哈希
                .compact(); //转换成字符串
        System.out.println(token);
        JwtParser parser = Jwts.parser();
        Jws<Claims> claimsJws = parser.setSigningKey(tockenSigKey).parseClaimsJws(token);
        Claims body = claimsJws.getBody();
        String subject = body.getSubject();
        Date issuedAt = body.getIssuedAt();
        Date notBefore = body.getNotBefore();
        String signature = claimsJws.getSignature();
        System.out.println(subject);
        System.out.println(notBefore);
        System.out.println(issuedAt);
        System.out.println(signature);
    }