我在Android中实现了一个项目，用户可以从谷歌驱动器备份和恢复文件。
然而，有一些问题，例如它在驱动器api sigining之后最初没有首次上传文件。我也可以看到谷歌驱动器中的更新文件，但下载旧文件时获取。请建议我一个解决方案。
这是我的代码
if (mGoogleApiClient == null) {
// Create the API client and bind it to an instance variable.
// We use this instance as the callback for connection and connection
// failures.
// Since no account name is passed, the user is prompted to choose.
mGoogleApiClient = new GoogleApiClient.Builder(Myportfolio.this)
.addApi(Drive.API)
.addScope(Drive.SCOPE_FILE)
.addConnectionCallbacks(Myportfolio.this)
.addOnConnectionFailedListener(Myportfolio.this)
.build();
}
mGoogleApiClient.connect();
@Override
public void onConnected(Bundle connectionHint) {
Log.i(TAG, "API client connected.");
Drive.DriveApi.requestSync(mGoogleApiClient).setResultCallback(new ResultCallback<com.google.android.gms.common.api.Status>() {
@Override
public void onResult(com.google.android.gms.common.api.Status status) {
if (!status.getStatus().isSuccess()) {
Log.e("SYNCING", "ERROR" + status.getStatusMessage());
} else {
Log.e("SYNCING", "SUCCESS");
// execute async task to list AppFolderContents
}
}
});
Query query = new Query.Builder()
.addFilter(Filters.eq(SearchableField.TITLE, "backup.txt"))
.build();
Drive.DriveApi.query(mGoogleApiClient, query)
.setResultCallback(new ResultCallback<DriveApi.MetadataBufferResult>() {
@Override
public void onResult(@NonNull DriveApi.MetadataBufferResult result) {
if (result.getMetadataBuffer().getCount() > 0) {
resu = String.valueOf(result.getMetadataBuffer().get(0).getDriveId().getResourceId());
Log.d("Value of id", resu);
// resu = resu.substring(resu.indexOf(":"));
if (status == 1) {
Drive.DriveApi.fetchDriveId(mGoogleApiClient, resu).setResultCallback(idCallback);
Log.d("Google:", "update");
} else if (status == 2) {
Drive.DriveApi.fetchDriveId(mGoogleApiClient, resu).setResultCallback(idCallback1);
Log.d("Google:", "fetch");
}
}
else {
Drive.DriveApi.newDriveContents(mGoogleApiClient).setResultCallback(driveContentsCallback);
Log.d("Google:", "create new");
}
}
});
}
final ResultCallback<DriveApi.DriveIdResult> idCallback = new ResultCallback<DriveApi.DriveIdResult>() {
@Override
public void onResult(DriveApi.DriveIdResult result) {
if (!result.getStatus().isSuccess()) {
Log.d("file status:","Cannot find DriveId. Are you authorized to view this file?");
return;
}
DriveId driveId = result.getDriveId();
DriveFile file = driveId.asDriveFile();
new EditContentsAsyncTask().execute(file);
}
};
final private ResultCallback<DriveApi.DriveContentsResult> driveContentsCallback = new
ResultCallback<DriveApi.DriveContentsResult>() {
@Override
public void onResult(DriveApi.DriveContentsResult result) {
if (!result.getStatus().isSuccess()) {
//showMessage("Error while trying to create new file contents");
return;
}
final DriveContents driveContents = result.getDriveContents();
// Perform I/O off the UI thread.
new Thread() {
@Override
public void run() {
// write content to DriveContents
OutputStream outputStream = driveContents.getOutputStream();
Writer writer = new OutputStreamWriter(outputStream);
try {
writer.write(resultSet.toString());
writer.close();
} catch (IOException e) {
Log.e(TAG, e.getMessage());
}
MetadataChangeSet changeSet = new MetadataChangeSet.Builder()
.setTitle("backup.txt")
.setMimeType("text/plain")
.setStarred(true).build();
// create a file on root folder
Drive.DriveApi.getRootFolder(mGoogleApiClient)
.createFile(mGoogleApiClient, changeSet, driveContents)
.setResultCallback(fileCallback);
// Drive.DriveApi.requestSync(mGoogleApiClient).await();
}
}.start();
}
};
final private ResultCallback<DriveFolder.DriveFileResult> fileCallback = new
ResultCallback<DriveFolder.DriveFileResult>() {
@Override
public void onResult(DriveFolder.DriveFileResult result) {
if (!result.getStatus().isSuccess()) {
// showMessage("Error while trying to create the file");
return;
}
// showMessage("Created a file with content: " + result.getDriveFile().getDriveId());
Toast.makeText(getBaseContext(), "Backup to cloud done", Toast.LENGTH_SHORT).show();
//Toast.makeText(Myportfolio.this, "Created a file with content: " + result.getDriveFile().getDriveId(), Toast.LENGTH_LONG).show();
Log.d("File Id: ", String.valueOf(result.getDriveFile().getDriveId()));
}
};
public class EditContentsAsyncTask extends AsyncTask<DriveFile, Void, Boolean> {
@Override
protected Boolean doInBackground(DriveFile... params) {
DriveFile file = params[0];
try {
DriveApi.DriveContentsResult driveContentsResult = file.open(
mGoogleApiClient, DriveFile.MODE_WRITE_ONLY, null).await();
if (!driveContentsResult.getStatus().isSuccess()) {
return false;
}
DriveContents driveContents = driveContentsResult.getDriveContents();
OutputStream outputStream = driveContents.getOutputStream();
outputStream.write(resultSet.toString().getBytes());
com.google.android.gms.common.api.Status status =
driveContents.commit(mGoogleApiClient, null).await();
return status.getStatus().isSuccess();
} catch (IOException e) {
Log.e(TAG, "IOException while appending to the output stream", e);
}
return false;
}
@Override
protected void onPostExecute(Boolean result) {
if (!result) {
// showMessage("Error while editing contents");
return;
}
Log.d("Update: ", "Done");
// showMessage("Successfully edited contents");
}
}
final private ResultCallback<DriveApi.DriveIdResult> idCallback1 = new ResultCallback<DriveApi.DriveIdResult>() {
@Override
public void onResult(DriveApi.DriveIdResult result) {
new RetrieveDriveFileContentsAsyncTask().execute(result.getDriveId());
}
};
public class RetrieveDriveFileContentsAsyncTask extends AsyncTask<DriveId, Boolean, String> {
@Override
protected String doInBackground(DriveId... params) {
String contents = null;
DriveFile file = params[0].asDriveFile();
DriveApi.DriveContentsResult driveContentsResult =
file.open(mGoogleApiClient, DriveFile.MODE_READ_ONLY, null).await();
if (!driveContentsResult.getStatus().isSuccess()) {
return null;
}
DriveContents driveContents = driveContentsResult.getDriveContents();
BufferedReader reader = new BufferedReader(
new InputStreamReader(driveContents.getInputStream()));
StringBuilder builder = new StringBuilder();
String line;
try {
while ((line = reader.readLine()) != null) {
builder.append(line);
}
contents = builder.toString();
} catch (IOException e) {
Log.e(TAG, "IOException while reading from the stream", e);
}
driveContents.discard(mGoogleApiClient);
return contents;
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
if (result == null) {
// showMessage("Error while reading from the file");
return;
}
// restoregoogle=result;
try {
if (result == null) {
return;
}
Toast.makeText(getBaseContext(), "Restored from cloud", Toast.LENGTH_SHORT).show();
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Log.d("Data from Cloud: ", result);
// showMessage("File contents: " + result);
}
}