title: How do I use the Android SyncAdapter?
body: <p>I try to understand the Android synchronization logic. What I don't understand is the file <code>syncadapter.xml</code> contained in the Android SDK sample project <code>SampleSyncAdapter</code>. If you downloaded the SDK samples it should be in the following folder:</p>
  
  <pre><code>SDK/android-sdk-PLATFORM/samples/android-VERSION/SampleSyncAdapter/res/xml/syncadapter.xml
  </code></pre>
  
  <p>I read, the authority of a content provider should be a string or a reference to a resource. What exactly is the content authority and where is <code>com.android.contacts</code>? Here is the content of the file (w/o license information and comments, API level 16).</p>
  
  <pre><code>&lt;sync-adapter xmlns:android="http://schemas.android.com/apk/res/android"
      android:contentAuthority="com.android.contacts"
      android:accountType="com.example.android.samplesync"
      android:supportsUploading="false"
      android:userVisible="true"
  /&gt;
  </code></pre>