# Data Synchronization with Sync Adapter
# Dummy Sync Adapter with Stub Provider
/**
* Define a sync adapter for the app.
* <p/>
* <p>This class is instantiated in {@link SyncService}, which also binds SyncAdapter to the system.
* SyncAdapter should only be initialized in SyncService, never anywhere else.
* <p/>
* <p>The system calls onPerformSync() via an RPC call through the IBinder object supplied by
* SyncService.
*/
class SyncAdapter extends AbstractThreadedSyncAdapter {
/**
* Constructor. Obtains handle to content resolver for later use.
*/
public SyncAdapter(Context context, boolean autoInitialize) {
super(context, autoInitialize);
}
/**
* Constructor. Obtains handle to content resolver for later use.
*/
public SyncAdapter(Context context, boolean autoInitialize, boolean allowParallelSyncs) {
super(context, autoInitialize, allowParallelSyncs);
}
@Override
public void onPerformSync(Account account, Bundle extras, String authority,
ContentProviderClient provider, SyncResult syncResult) {
//Jobs you want to perform in background.
Log.e("" + account.name, "Sync Start");
}
}
/**
* Define a Service that returns an IBinder for the
* sync adapter class, allowing the sync adapter framework to call
* onPerformSync().
*/
public class SyncService extends Service {
// Storage for an instance of the sync adapter
private static SyncAdapter sSyncAdapter = null;
// Object to use as a thread-safe lock
private static final Object sSyncAdapterLock = new Object();
/*
* Instantiate the sync adapter object.
*/
@Override
public void onCreate() {
/*
* Create the sync adapter as a singleton.
* Set the sync adapter as syncable
* Disallow parallel syncs
*/
synchronized (sSyncAdapterLock) {
if (sSyncAdapter == null) {
sSyncAdapter = new SyncAdapter(getApplicationContext(), true);
}
}
}
/**
* Return an object that allows the system to invoke
* the sync adapter.
*/
@Override
public IBinder onBind(Intent intent) {
/*
* Get the object that allows external processes
* to call onPerformSync(). The object is created
* in the base class code when the SyncAdapter
* constructors call super()
*/
return sSyncAdapter.getSyncAdapterBinder();
}
}
public class Authenticator extends AbstractAccountAuthenticator {
// Simple constructor
public Authenticator(Context context) {
super(context);
}
// Editing properties is not supported
@Override
public Bundle editProperties(
AccountAuthenticatorResponse r, String s) {
throw new UnsupportedOperationException();
}
// Don't add additional accounts
@Override
public Bundle addAccount(
AccountAuthenticatorResponse r,
String s,
String s2,
String[] strings,
Bundle bundle) throws NetworkErrorException {
return null;
}
// Ignore attempts to confirm credentials
@Override
public Bundle confirmCredentials(
AccountAuthenticatorResponse r,
Account account,
Bundle bundle) throws NetworkErrorException {
return null;
}
// Getting an authentication token is not supported
@Override
public Bundle getAuthToken(
AccountAuthenticatorResponse r,
Account account,
String s,
Bundle bundle) throws NetworkErrorException {
throw new UnsupportedOperationException();
}
// Getting a label for the auth token is not supported
@Override
public String getAuthTokenLabel(String s) {
throw new UnsupportedOperationException();
}
// Updating user credentials is not supported
@Override
public Bundle updateCredentials(
AccountAuthenticatorResponse r,
Account account,
String s, Bundle bundle) throws NetworkErrorException {
throw new UnsupportedOperationException();
}
// Checking features for the account is not supported
@Override
public Bundle hasFeatures(
AccountAuthenticatorResponse r,
Account account, String[] strings) throws NetworkErrorException {
throw new UnsupportedOperationException();
}
}
/**
* A bound Service that instantiates the authenticator
* when started.
*/
public class AuthenticatorService extends Service {
// Instance field that stores the authenticator object
private Authenticator mAuthenticator;
@Override
public void onCreate() {
// Create a new authenticator object
mAuthenticator = new Authenticator(this);
}
/*
* When the system binds to this Service to make the RPC call
* return the authenticator's IBinder.
*/
@Override
public IBinder onBind(Intent intent) {
return mAuthenticator.getIBinder();
}
}
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<uses-permission android:name="android.permission.READ_SYNC_SETTINGS" />
<uses-permission android:name="android.permission.WRITE_SYNC_SETTINGS" />
<uses-permission android:name="android.permission.AUTHENTICATE_ACCOUNTS" />
<service
android:name=".syncAdapter.SyncService"
android:exported="true">
<intent-filter>
<action android:name="android.content.SyncAdapter" />
</intent-filter>
<meta-data
android:name="android.content.SyncAdapter"
android:resource="@xml/syncadapter" />
</service>
<service android:name=".authenticator.AuthenticatorService">
<intent-filter>
<action android:name="android.accounts.AccountAuthenticator" />
</intent-filter>
<meta-data
android:name="android.accounts.AccountAuthenticator"
android:resource="@xml/authenticator" />
</service>
<provider
android:name=".provider.StubProvider"
android:authorities="com.yourpackage.provider"
android:exported="false"
android:syncable="true" />
<?xml version="1.0" encoding="utf-8"?>
<account-authenticator xmlns:android="http://schemas.android.com/apk/res/android"
android:accountType="com.yourpackage"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:smallIcon="@mipmap/ic_launcher" />
<?xml version="1.0" encoding="utf-8"?>
<sync-adapter xmlns:android="http://schemas.android.com/apk/res/android"
android:accountType="com.yourpackage.android"
android:allowParallelSyncs="false"
android:contentAuthority="com.yourpackage.provider"
android:isAlwaysSyncable="true"
android:supportsUploading="false"
android:userVisible="false" />
/*
* Define an implementation of ContentProvider that stubs out
* all methods
*/
public class StubProvider extends ContentProvider {
/*
* Always return true, indicating that the
* provider loaded correctly.
*/
@Override
public boolean onCreate() {
return true;
}
/*
* Return no type for MIME type
*/
@Override
public String getType(Uri uri) {
return null;
}
/*
* query() always returns no results
*
*/
@Override
public Cursor query(
Uri uri,
String[] projection,
String selection,
String[] selectionArgs,
String sortOrder) {
return null;
}
/*
* insert() always returns null (no URI)
*/
@Override
public Uri insert(Uri uri, ContentValues values) {
return null;
}
/*
* delete() always returns "no rows affected" (0)
*/
@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
return 0;
}
/*
* update() always returns "no rows affected" (0)
*/
public int update(
Uri uri,
ContentValues values,
String selection,
String[] selectionArgs) {
return 0;
}
}
public Account CreateSyncAccount(Context context, String accountName) {
// Create the account type and default account
Account newAccount = new Account(
accountName, "com.yourpackage");
// Get an instance of the Android account manager
AccountManager accountManager =
(AccountManager) context.getSystemService(
ACCOUNT_SERVICE);
/*
* Add the account and account type, no password or user data
* If successful, return the Account object, otherwise report an error.
*/
if (accountManager.addAccountExplicitly(newAccount, null, null)) {
/*
* If you don't set android:syncable="true" in
* in your <provider> element in the manifest,
* then call context.setIsSyncable(account, AUTHORITY, 1)
* here.
*/
} else {
/*
* The account exists or some other error occurred. Log this, report it,
* or handle it internally.
*/
}
return newAccount;
}
Bundle bundle = new Bundle();
bundle.putBoolean(ContentResolver.SYNC_EXTRAS_EXPEDITED, true);
bundle.putBoolean(ContentResolver.SYNC_EXTRAS_FORCE, true);
bundle.putBoolean(ContentResolver.SYNC_EXTRAS_MANUAL, true);
ContentResolver.requestSync(null, MyContentProvider.getAuthority(), bundle);