我认为你应该阅读下面一些有用的链接:
然后,请参考以下代码片段,当然在获取输入流时,你可以将其保存到设备中的文件而不是打印到 Logcat 中。
public class GoogleDriveActivity extends AppCompatActivity
implements GoogleApiClient.ConnectionCallbacks,
GoogleApiClient.OnConnectionFailedListener {
...
@Override
protected void onCreate(Bundle savedInstanceState) {
...
mProgressBar = (ProgressBar) findViewById(R.id.progressBar);
mProgressBar.setMax(100);
}
@Override
protected void onResume() {
super.onResume();
if (mGoogleApiClient == null) {
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addApi(Drive.API)
.addScope(Drive.SCOPE_FILE)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.build();
}
mGoogleApiClient.connect();
}
@Override
protected void onPause() {
if (mGoogleApiClient != null) {
mGoogleApiClient.disconnect();
}
super.onPause();
}
@Override
protected void onActivityResult(final int requestCode, final int resultCode, final Intent data) {
if (requestCode == RC_OPENER && resultCode == RESULT_OK) {
mSelectedFileDriveId = data.getParcelableExtra(
OpenFileActivityBuilder.EXTRA_RESPONSE_DRIVE_ID);
}
}
@Override
public void onConnectionFailed(@NonNull ConnectionResult result) {
}
@Override
public void onConnected(@Nullable Bundle bundle) {
if (mSelectedFileDriveId != null) {
open();
return;
}
IntentSender intentSender = Drive.DriveApi
.newOpenFileActivityBuilder()
.setMimeType(new String[]{"video/mp4", "image/jpeg", "text/plain"})
.build(mGoogleApiClient);
try {
startIntentSenderForResult(intentSender, RC_OPENER, null, 0, 0, 0);
} catch (IntentSender.SendIntentException e) {
Log.e(TAG, "Unable to send intent", e);
}
}
@Override
public void onConnectionSuspended(int i) {
}
private void open() {
mProgressBar.setProgress(0);
DriveFile.DownloadProgressListener listener = new DriveFile.DownloadProgressListener() {
@Override
public void onProgress(long bytesDownloaded, long bytesExpected) {
int progress = (int) (bytesDownloaded * 100 / bytesExpected);
Log.d(TAG, String.format("Loading progress: %d percent", progress));
mProgressBar.setProgress(progress);
}
};
DriveFile driveFile = mSelectedFileDriveId.asDriveFile();
driveFile.open(mGoogleApiClient, DriveFile.MODE_READ_ONLY, listener)
.setResultCallback(driveContentsCallback);
mSelectedFileDriveId = null;
}
private final ResultCallback<DriveApi.DriveContentsResult> driveContentsCallback =
new ResultCallback<DriveApi.DriveContentsResult>() {
@Override
public void onResult(@NonNull DriveApi.DriveContentsResult result) {
if (!result.getStatus().isSuccess()) {
Log.w(TAG, "Error while opening the file contents");
return;
}
Log.i(TAG, "File contents opened");
DriveContents driveContents = result.getDriveContents();
BufferedReader reader = new BufferedReader(new InputStreamReader(driveContents.getInputStream()));
StringBuilder builder = new StringBuilder();
String line;
try {
while ((line = reader.readLine()) != null) {
builder.append(line);
}
} catch (IOException e) {
e.printStackTrace();
}
String contentsAsString = builder.toString();
Log.i(TAG, contentsAsString);
driveContents.discard(mGoogleApiClient);
}
};
}