操作已完成,HTTP状态代码409(失败)

Next Cloud Api,我正在尝试从我的设备上传图像,作为:

    uploadButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            showFileChooser();
        }
    });

    private void showFileChooser() {
       Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
       intent.setType("*/*");
       intent.addCategory(Intent.CATEGORY_OPENABLE);

       try {
          startActivityForResult(
          Intent.createChooser(intent, "Select a File to Upload"),FILE_SELECT_CODE);
       } catch (android.content.ActivityNotFoundException ex) {
          // Potentially direct the user to the Market with a Dialog
          Toast.makeText(this, "Please install a File Manager.",
                Toast.LENGTH_SHORT).show();
       }
    }

     @Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    switch (requestCode) {
        case FILE_SELECT_CODE:
            if (resultCode == RESULT_OK) {
                try {
                    // Get the Uri of the selected file
                    Uri uri = data.getData();
                    // Get the path
                    String path = getPath(MainActivity.this, uri);
                    File fi = new File(path);

                    //set the image to image view
                    iv.setImageURI(Uri.fromFile(fi));

                    Date lastModDate = new Date(fi.lastModified());
                    startUpload(fi, "/testfolder", getMimeType2(Uri.fromFile(fi)),lastModDate.toString());
                    Log.e(TAG, "file " + fi.toString() + " remote path " + mServerUri + " mime " + getMimeType2(Uri.fromFile(fi))+" date "+lastModDate.toString());
                } catch (Exception e) {
                    Log.e(TAG, "eee " + e.toString());
                }
            }
            break;
    }
    super.onActivityResult(requestCode, resultCode, data);
}

public static String getPath(Context context, Uri uri) throws URISyntaxException {
    if ("content".equalsIgnoreCase(uri.getScheme())) {
        String[] projection = {"_data"};
        Cursor cursor = null;

        try {
            cursor = context.getContentResolver().query(uri, projection, null, null, null);
            int column_index = cursor.getColumnIndexOrThrow("_data");
            if (cursor.moveToFirst()) {
                return cursor.getString(column_index);
            }
        } catch (Exception e) {
            // Eat it
        }
    } else if ("file".equalsIgnoreCase(uri.getScheme())) {
        return uri.getPath();
    }

    return null;
}

虽然我刚刚用 api documentation

问题是从设备上传的图像!我在尝试上载时出现以下错误:

  Operation finished with HTTP status code 409 (fail)