GDAA（Google Drive Android API）：使用fileId从AppDataFolder下载文件

Question

I'm using google drive in my app. I'm able to upload data in Google drive App folder and getting the file id. My Question is, how to download it from appDataFolder by using FileId This is how i'm getting the file ids

     private List<String> getDataFromApi() throws IOException {

        List<String> fileInfo = new ArrayList<String>();
        FileList lst = mService.files().list()
                .setSpaces("appDataFolder")
                .execute();

        FileList result = mService.files().list()
                .setSpaces("appDataFolder")
                .setFields("nextPageToken, files(id, name, mimeType)")
                .execute();
        List<File> files = result.getFiles();
        if (files != null) {
            for (File file : files) {
                fileInfo.add(String.format("%s (%s) %s\n",
                        file.getName(), file.getId(), file.getMimeType()));
            }
        }
        return fileInfo;
    }

I'm using v3 of google drive services.

compile('com.google.apis:google-api-services-drive:v3-rev102-1.23.0') {
    exclude group: 'org.apache.httpcomponents'
}

Thanks In Advance

Answer 1

Finally I got My answer. Hope this will help to others also for downloading from appDataFolder . Here I'm downloading and saving the file into SD card folder name Spectors . And passing the value of File type of com.google.api.services.api.drive.model.File .

       private void downloadFile(boolean useDirectDownload, File uploadedFile)
            throws IOException {


        java.io.File direct = new java.io.File(Environment.getExternalStorageDirectory()
                + "/Spectors");
        if (!direct.exists()) {
            direct.mkdirs();
        }

        java.io.File parentDir = new java.io.File(direct.getAbsolutePath());
        if (!parentDir.exists() && !parentDir.mkdirs()) {
            throw new IOException("Unable to create parent directory");
        }
        OutputStream out = new FileOutputStream(new java.io.File(parentDir, uploadedFile.getName()+".zip"));
        com.google.api.services.drive.Drive.Files.Get files = mService.files().get(uploadedFile.getId());
        files.executeMediaAndDownloadTo(out);

        Log.e(TAG, "downloadFile:2 " + files.toString() + "\n"+uploadedFile.getFileExtension() );
}

Answer 2

you can also apply following approach to download the content from app folder

get files from app folder by the following code

private void listFiles() {
    Query query =
            new Query.Builder()
                    .addFilter(Filters.or(Filters.eq(SearchableField.MIME_TYPE, "text/html"),
                            Filters.eq(SearchableField.MIME_TYPE, "text/plain")))
                    .build();
    getDriveResourceClient()
            .query(query)

            .addOnSuccessListener(this,

                    new OnSuccessListener<MetadataBuffer>() {
                        @Override
                        public void onSuccess(MetadataBuffer metadataBuffer) {
                            //mResultsAdapter.append(metadataBuffer);

                            for (int i = 0; i <metadataBuffer.getCount() ; i++) {
                                retrieveContents(metadataBuffer.get(i).getDriveId().asDriveFile());
                            }
                        }
                    }

            )
            .addOnFailureListener(this, new OnFailureListener() {
                @Override
                public void onFailure(@NonNull Exception e) {
                    Log.e(TAG, "Error retrieving files", e);
                    MainActivity.this.finish();
                }
            });

}

to download the content the the following code

 private void retrieveContents(DriveFile file) {
        // [START drive_android_open_file]
        Task<DriveContents> openFileTask =
                getDriveResourceClient().openFile(file, DriveFile.MODE_READ_ONLY);
        // [END drive_android_open_file]
        // [START drive_android_read_contents]
        openFileTask
                .continueWithTask(task -> {
                    DriveContents contents = task.getResult();
                    // Process contents...
                    // [START_EXCLUDE]
                    // [START drive_android_read_as_string]
                    try (BufferedReader reader = new BufferedReader(
                                 new InputStreamReader(contents.getInputStream()))) {
                        StringBuilder builder = new StringBuilder();
                        String line;
                        while ((line = reader.readLine()) != null) {
                            builder.append(line).append("\n");
                        }
                        showMessage(getString(R.string.content_loaded));
                        mFileContents.setText(builder.toString());
                    }
                    // [END drive_android_read_as_string]
                    // [END_EXCLUDE]
                    // [START drive_android_discard_contents]
                    Task<Void> discardTask = getDriveResourceClient().discardContents(contents);
                    // [END drive_android_discard_contents]
                    return discardTask;
                })
                .addOnFailureListener(e -> {
                    // Handle failure
                    // [START_EXCLUDE]
                    Log.e(TAG, "Unable to read contents", e);
                    showMessage(getString(R.string.read_failed));
                    finish();
                    // [END_EXCLUDE]
                });
        // [END drive_android_read_contents]
    }