public class JwtUtil {

private static Algorithm algorithm;

static {

try {

algorithm = Algorithm.HMAC512(KeyGenerator.getInstance("HmacSHA512").generateKey().getEncoded());

} catch (NoSuchAlgorithmException e) {

e.printStackTrace();

}

}

public static String create(String username) {

Date now = new Date();

return JWT.create()

.withIssuedAt(now)

.withClaim("username", username)

.withExpiresAt(new Date(now.getTime() + 60000*60))

.sign(algorithm);

}

public static String verify(String token) {

return JWT.require(algorithm).build()

.verify(token)

.getClaim("username")

.asString();

}

}

上面是 jwt 的生成和验证的类

public class TestToken {

public static void main(String[] args) {

String token = JwtUtil.create("123");

System.out.println(token);

System.out.println(JwtUtil.verify("eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzUxMiJ9.eyJleHAiOjE1NzM4MTU2MzYsImlhdCI6MTU3MzgxMjAzNiwidXNlcm5hbWUiOiIxMjMifQ.4xIgdDx44A_4vdebICw-FmzxMqw5R48OODJ7HPst4rEe-4k2ob1cKat2CKqw7VSTsKAEBl1abxv6EpBU5AhIwg"));

}

}

问题：当我把获得的 token 手动填入到这个测试类里的时候，就是给我报一个错 com.auth0.jwt.exceptions.SignatureVerificationException: The Token's Signature resulted invalid when verified using the Algorithm: HmacSHA512，但是如果我直接写成JwtUtil.verify(token)，一切就 ok，请问这是为什么？(手动填入的 token 是正确的，未过期的)