file.saveInBackground(new SaveCallback() {
                            @Override
                            public void done(AVException e) {
                                if(e!=null){
                                    System.out.println("error" + e.getMessage());
                                    //上传失败
                                }else{
                                    //上传成功
                                    System.out.println("Success");
                                }
                            }
                        }, new ProgressCallback() {
                            @Override
                            public void done(Integer percentDone) {

                                System.out.println("uploading: " + percentDone);
                                //打印进度
                            }
                        });

errorInvalid value type for field 'bucket',expect type is {:type "Object"},but it is '{:type "String"}'