Check File exist before uploading DropBoxApi

Entry existingentry= dropbox.metadata(path + "sample.txt",1,null,false,null);

Actual Method:

protected Boolean doInBackground(Void... params) {
    final File tempDir = context.getCacheDir();
    File tempFile;
    FileWriter fr;
    try {
        tempFile = File.createTempFile("file", ".txt", tempDir);
        fr = new FileWriter(tempFile);
        fr.write("Test file uploaded using Dropbox API for Android");
        fr.close();

        FileInputStream fileInputStream = new FileInputStream(tempFile);

      Entry existingentry= dropbox.metadata(path + "sample.txt",1,null,false,null);

            dropbox.putFile(path + "sample.txt", fileInputStream,
                    tempFile.length(), null, null);
            tempFile.delete();

        return true;
    } catch (IOException e) {
        e.printStackTrace();
    } catch (DropboxException e) {
        e.printStackTrace();
    }
    return false;
}


@Override
protected void onPostExecute(Boolean result) {
    if (result) {
        Toast.makeText(context, "File Uploaded Successfully!",
                Toast.LENGTH_LONG).show();
    } else {
        Toast.makeText(context, "Failed to upload file", Toast.LENGTH_LONG)
                .show();
    }
}