Read AppFolder file data in android

Question

I want to read the i have written on a file in Appfolder.but i am not able to read that my app is crashes when i try to read that from file.i have created the file in App folder successfully.i am using the below code so please tell if i am doing anything wrong.The error which is coming while i run this code is invalid drive id.i am getting that drive id by this:

result.getDriveFile().getDriveId().encodeToString()

where result is drivefileresult. May I know what is the correct way to achieve my objective?

public class Fifth extends BaseDemoActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_fifth);
    }

     @Override
        public void onConnected(Bundle connectionHint) {
            super.onConnected(connectionHint);
            // create new contents resource

            Drive.DriveApi.newContents(getGoogleApiClient())
                    .setResultCallback(contentsCallback);
        }

        final private ResultCallback<ContentsResult> contentsCallback = new
                ResultCallback<ContentsResult>() {
            @Override
            public void onResult(ContentsResult result) {
                if (!result.getStatus().isSuccess()) {
                    showMessage("Error while trying to create new file contents");
                    return;
                }
                // Get an output stream for the contents.
                OutputStream outputStream = result.getContents().getOutputStream();
                // Write the bitmap data from it.
                String data="hello world. this is sample";
                 byte[] bytes = data.getBytes();

              //  ByteArrayOutputStream bitmapStream = new ByteArrayOutputStream();

         //      image.compress(Bitmap.CompressFormat.PNG, 100, bitmapStream);
                try {
                    Log.i("Success", "able to write file contents.");
                    outputStream.write(bytes);
                } catch (IOException e1) {
                    Log.i("Failier", "Unable to write file contents.");
                }
                MetadataChangeSet changeSet = new MetadataChangeSet.Builder()
                        .setTitle("appdatafolder.txt")
                        .setMimeType("text/plain")
                        .build();

                Drive.DriveApi.getAppFolder(getGoogleApiClient())
                        .createFile(getGoogleApiClient(), changeSet, result.getContents())
                        .setResultCallback(fileCallback);
            }
        };

        final private ResultCallback<DriveFileResult> fileCallback = new
                ResultCallback<DriveFileResult>() {
            @Override
            public void onResult(DriveFileResult result) {
                if (!result.getStatus().isSuccess()) {
                    showMessage("Error while trying to create the file");
                    return;
                }


                showMessage("Created a file in App Folder: "
                        + result.getDriveFile().getDriveId());
                Log.i("Drioved_ID", result.getDriveFile().getDriveId().encodeToString());
            }
        };

}

Answer 1

Unfortunately I don't have time to analyze your code but can offer a segment that does essentially the same. Try it.

GoogleApiClient gac = getGoogleApiClient();
DriveFolder dfl = Drive.DriveApi.getAppFolder(gac)
String title = "appdatafolder.txt";
String mime = "text/plain";
byte[] buff = ("hello world. this is sample").getBytes();
createFile(gac, dfl, title, mime, buff);

void createFile(final GoogleApiClient gac, final DriveFolder fldr, 
    final String name, final String mime, final byte[] buff) {
  Thread t = new Thread(new Runnable() {
    @Override public void run() {
      try { 
        ContentsResult rslt = Drive.DriveApi.newContents(gac).await();
        if (rslt.getStatus().isSuccess()) {
          Contents cont = rslt.getContents();    
          cont.getOutputStream().write(buff);
          MetadataChangeSet meta = 
              new MetadataChangeSet.Builder().setTitle(name).setMimeType(mime).build();
          DriveFile df = fldr.createFile(gac, meta, cont).await().getDriveFile();
          Log.i("X", ""+ df.getDriveId().encodeToString());
        }
      } catch (Exception e) {}
    }
  });
  t.start();
}

... and here is how you read it back:

void getFileIs(final GoogleApiClient gac, final DriveId drvId) {
  Thread t = new Thread(new Runnable() {
    @Override public void run() {
      try {
        DriveFile df = Drive.DriveApi.getFile(gac, drvId);
        ContentsResult rslt = df.openContents(gac, DriveFile.MODE_READ_ONLY, null).await();
        if (rslt.getStatus().isSuccess()){
          InputStream is = rslt.getContents().getInputStream();
        }
      } catch (Exception e) {}
    }
  });
  t.start();
}