如何解决parseContent.isSuccess上的“'在空对象引用上的'int java.lang.String.length（）'”错误（响应）

Question

我想将图像从android上传到php服务器（laravel框架）。当我从图库中选择图片时，我会得到

  

在空对象引用上调用虚拟方法'int java.lang.String.length（）'

命令错误

  

如果（parseContent.isSuccess（response））

这是我的代码。在创建中：

btn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent galleryIntent = new Intent(Intent.ACTION_PICK,
                    android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);

            startActivityForResult(galleryIntent, GALLERY);
        }
    });

和

@Override
 public void onActivityResult(int requestCode, int resultCode, Intent data) {

super.onActivityResult(requestCode, resultCode, data);
if (resultCode == this.getActivity().RESULT_CANCELED) {
    return;
}
if (requestCode == GALLERY) {
    if (data != null) {
        Uri contentURI = data.getData();
        try {
            Bitmap bitmap = MediaStore.Images.Media.getBitmap(this.getActivity().getContentResolver(), contentURI);
            String path = saveImage(bitmap);

            uploadImageToServer(path);

            //imageview.setImageBitmap(bitmap);

        } catch (IOException e) {
            e.printStackTrace();
            Toast.makeText(view.getContext(), "Failed!", Toast.LENGTH_SHORT).show();
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }
}


private void uploadImageToServer(final String path) throws IOException, JSONException {

    if (!Utils.isNetworkAvailable(view.getContext())) {
        Toast.makeText(view.getContext(), "Internet is required!", Toast.LENGTH_SHORT).show();
        return;
    }

    HashMap<String, String> map = new HashMap<String, String>();
    map.put("url", "https://satrapmobile.ir/uploadImage");
    map.put("filename", path);
    new MultiPartRequester(this.getActivity(), map, GALLERY,this);
    Utils.showSimpleProgressDialog(view.getContext());
}

@Override
public void onTaskCompleted(String response, int serviceCode) {
    Utils.removeSimpleProgressDialog();
    Log.d("res", response.toString());
    switch (serviceCode) {
        case GALLERY:
            ***if (parseContent.isSuccess(response))*** {
                String url = parseContent.getURL(response);
                aQuery.id(imageview).image(url);
            }
    }
}

在ParseContent类中：

 public boolean isSuccess(String response) {

    try {
        JSONObject jsonObject = new JSONObject(response);
        if (jsonObject.optString(KEY_SUCCESS).equals("true")) {
            return true;
        } else {

            return false;
        }

    } catch (JSONException e) {
        e.printStackTrace();
    }
    return false;
}

请帮助我