Why my Qiniu SDK have no Json.class

[chenzhaoyan]

public String uploadTokenWithDeadline(String bucket, String key, long deadline, StringMap policy, boolean strict) {
// TODO UpHosts Global
String scope = bucket;
if (key != null) {
scope = bucket + ":" + key;
}
StringMap x = new StringMap();
copyPolicy(x, policy, strict);
x.put("scope", scope);
x.put("deadline", deadline);

    String s = Json.encode(x);
    return signWithData(StringUtils.utf8Bytes(s));
}

public String uploadTokenWithPolicy(Object obj) {
    String s = Json.encode(obj);
    return signWithData(StringUtils.utf8Bytes(s));
}

[longbai]

https://github.com/qiniu/java-sdk/blob/master/src/main/java/com/qiniu/util/Json.java 在这里，麻烦贴下错误信息