我正在尝试将图像从我的Android应用上传到Google云端硬盘，

基于本教程。

当我调试他们的示例项目时，我看到一个典型的fileUri =

file:///storage/sdcard0/Pictures/IMG_20131117_090231.jpg

在我的应用中，我想上传现有照片。

我这样检索它的路径

     private void GetAnyImage()
        {
            File dir = new File(Environment.getExternalStorageDirectory()
            .getAbsolutePath() + "/Pictures/Screenshots"); 
                              // --> /storage/sdcard0/Pictures/Screenshots

            Log.d("File path ", dir.getPath());
            String dirPath=dir.getAbsolutePath();
            if(dir.exists() && dir.isDirectory()) {
                Intent intent = new Intent(Intent.ACTION_GET_CONTENT, null);
                intent.setType("image/*");
                startActivityForResult(intent,REQUEST_ID);
            }  
        }

并最终得到这个典型的fileUri =content://media/external/images/media/74275

但是，当运行此行代码时

  private void saveFileToDrive() {

    //  progressDialog = ProgressDialog.show(this, "", "Loading...");

    Thread t = new Thread(new Runnable() {
      @Override
      public void run() {
        try {
          // File's binary content
          java.io.File fileContent = new java.io.File(fileUri.getPath());
          FileContent mediaContent = new FileContent("image/jpeg", fileContent);

      // File's metadata.
      File body = new File();
      body.setTitle(fileContent.getName());
      body.setMimeType("image/jpeg");

      File file = service.files().insert(body, mediaContent).execute();

我收到一个错误：

java.io.FileNotFoundException: /external/images/media/74275: open failed: ENOENT (No such file or directory)

我该如何解决？

怎么转换content://media/external/images/media/Y成file:///storage/sdcard0/Pictures/X.jpg？