AbstractThreadedSyncAdapter

public abstract class AbstractThreadedSyncAdapter
extends Object

An abstract implementation of a SyncAdapter that spawns a thread to invoke a sync operation. If a sync operation is already in progress when a sync request is received, an error will be returned to the new request and the existing request will be allowed to continue. However if there is no sync in progress then a thread will be spawned and onPerformSync(Account, Bundle, String, ContentProviderClient, SyncResult) will be invoked on that thread.

Syncs can be cancelled at any time by the framework. For example a sync that was not user-initiated and lasts longer than 30 minutes will be considered timed-out and cancelled. Similarly the framework will attempt to determine whether or not an adapter is making progress by monitoring its network activity over the course of a minute. If the network traffic over this window is close enough to zero the sync will be cancelled. You can also request the sync be cancelled via ContentResolver#cancelSync(Account, String) or ContentResolver#cancelSync(SyncRequest).

A sync is cancelled by issuing a Thread#interrupt() on the syncing thread. Either your code in onPerformSync(android.accounts.Account, android.os.Bundle, java.lang.String, android.content.ContentProviderClient, android.content.SyncResult) must check Thread#interrupted(), or you you must override one of onSyncCanceled(java.lang.Thread)/onSyncCanceled() (depending on whether or not your adapter supports syncing of multiple accounts in parallel). If your adapter does not respect the cancel issued by the framework you run the risk of your app's entire process being killed.

In order to be a sync adapter one must extend this class, provide implementations for the abstract methods and write a service that returns the result of getSyncAdapterBinder() in the service's Service.onBind(android.content.Intent) when invoked with an intent with action android.content.SyncAdapter. This service must specify the following intent filter and metadata tags in its AndroidManifest.xml file

   <intent-filter>
     <action android:name="android.content.SyncAdapter" />
   </intent-filter>
   <meta-data android:name="android.content.SyncAdapter"
             android:resource="@xml/syncadapter" />
 

 <sync-adapter xmlns:android="http://schemas.android.com/apk/res/android"
    android:contentAuthority="authority"
    android:accountType="accountType"
    android:userVisible="true|false"
    android:supportsUploading="true|false"
    android:allowParallelSyncs="true|false"
    android:isAlwaysSyncable="true|false"
    android:syncAdapterSettingsAction="ACTION_OF_SETTINGS_ACTIVITY"
 />
 

• The android:contentAuthority and android:accountType attributes indicate which content authority and for which account types this sync adapter serves.
• android:userVisible defaults to true and controls whether or not this sync adapter shows up in the Sync Settings screen.
• android:supportsUploading defaults to true and if true an upload-only sync will be requested for all syncadapters associated with an authority whenever that authority's content provider does a ContentResolver#notifyChange(android.net.Uri, android.database.ContentObserver, boolean) with syncToNetwork set to true.
• android:allowParallelSyncs defaults to false and if true indicates that the sync adapter can handle syncs for multiple accounts at the same time. Otherwise the SyncManager will wait until the sync adapter is not in use before requesting that it sync an account's data.
• android:isAlwaysSyncable defaults to false and if true tells the SyncManager to initialize the isSyncable state to 1 for that sync adapter for each account that is added.
• android:syncAdapterSettingsAction defaults to null and if supplied it specifies an Intent action of an activity that can be used to adjust the sync adapter's sync settings. The activity must live in the same package as the sync adapter.

Summary

Constants

public static final int LOG_SYNC_DETAILS

Public constructors

public AbstractThreadedSyncAdapter (Context context, 
                boolean autoInitialize)

public AbstractThreadedSyncAdapter (Context context, 
                boolean autoInitialize, 
                boolean allowParallelSyncs)

Public methods

public Context getContext ()

public final IBinder getSyncAdapterBinder ()

public abstract void onPerformSync (Account account, 
                Bundle extras, 
                String authority, 
                ContentProviderClient provider, 
                SyncResult syncResult)

public void onSecurityException (Account account, 
                Bundle extras, 
                String authority, 
                SyncResult syncResult)

public void onSyncCanceled (Thread thread)

public void onSyncCanceled ()

public boolean onUnsyncableAccount ()