java如何转换`content://media/external/images/media/Y`到`file:///storage/sdcard0/Pictures/X.jpg`在安卓中？

Question

我正在尝试从我的安卓应用程序将图像上传到Google Drive

基于此tutorial

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

在我的应用程序中，我想上传一张现有照片

我就这样找到了它的路径

     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);
            }  
        }

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

但是，当运行这行代码时

  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();

我得到一个错误：

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

我怎样才能解决这个问题

如何将content://media/external/images/media/Y转换为file:///storage/sdcard0/Pictures/X.jpg

Answer 1

如果你只是想要位图，这个也可以

InputStream inputStream = mContext.getContentResolver().openInputStream(uri);
Bitmap bmp = BitmapFactory.decodeStream(inputStream);
if( inputStream != null ) inputStream.close();

示例uri：content://media/external/images/media/12345

Answer 2

像这样的东西对你有用吗？这样做的目的是查询内容解析程序以查找为该内容条目存储的文件路径数据

public static String getRealPathFromUri(Context context, Uri contentUri) {
    Cursor cursor = null;
    try {
        String[] proj = { MediaStore.Images.Media.DATA };
        cursor = context.getContentResolver().query(contentUri, proj, null, null, null);
        int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        cursor.moveToFirst();
        return cursor.getString(column_index);
    } finally {
        if (cursor != null) {
            cursor.close();
        }
    }
}

这将最终为您提供一个绝对文件路径，您可以从该路径构造文件uri