我猜是与清单文件和权限相关的东西，服务在最后一个活动之后启动，更新服务器上的数据并检索新数据并在android上的sqlite上保存id：
此处还有清单文件：
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.ggservice.democracy"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.ggservice.democracy.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:label="@string/app_name" android:name="com.ggservice.democracy.sondaggioActivity"/>
<activity android:label="@string/app_name" android:name="com.ggservice.democracy.domandeDiCategoria"/>
<service android:name="com.ggservice.democracy.updateDemocracyService" />
</application>
</manifest>
logcat：
01-02 15:33:30.960: W/dalvikvm(2570): threadid=1: thread exiting with uncaught exception (group=0x409c01f8)
01-02 15:33:31.160: E/AndroidRuntime(2570): FATAL EXCEPTION: main
01-02 15:33:31.160: E/AndroidRuntime(2570): java.lang.RuntimeException: Unable to start service com.ggservice.democracy.updateDemocracyService@412f0c60 with Intent { cmp=com.ggservice.democracy/.updateDemocracyService }: android.os.NetworkOnMainThreadException
01-02 15:33:31.160: E/AndroidRuntime(2570): at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:2376)
01-02 15:33:31.160: E/AndroidRuntime(2570): at android.app.ActivityThread.access$1900(ActivityThread.java:123)
01-02 15:33:31.160: E/AndroidRuntime(2570): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1210)
01-02 15:33:31.160: E/AndroidRuntime(2570): at android.os.Handler.dispatchMessage(Handler.java:99)
01-02 15:33:31.160: E/AndroidRuntime(2570): at android.os.Looper.loop(Looper.java:137)
01-02 15:33:31.160: E/AndroidRuntime(2570): at android.app.ActivityThread.main(ActivityThread.java:4424)
01-02 15:33:31.160: E/AndroidRuntime(2570): at java.lang.reflect.Method.invokeNative(Native Method)
01-02 15:33:31.160: E/AndroidRuntime(2570): at java.lang.reflect.Method.invoke(Method.java:511)
01-02 15:33:31.160: E/AndroidRuntime(2570): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
01-02 15:33:31.160: E/AndroidRuntime(2570): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
01-02 15:33:31.160: E/AndroidRuntime(2570): at dalvik.system.NativeStart.main(Native Method)
01-02 15:33:31.160: E/AndroidRuntime(2570): Caused by: android.os.NetworkOnMainThreadException
01-02 15:33:31.160: E/AndroidRuntime(2570): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1099)
01-02 15:33:31.160: E/AndroidRuntime(2570): at java.net.InetAddress.lookupHostByName(InetAddress.java:391)
01-02 15:33:31.160: E/AndroidRuntime(2570): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:242)
01-02 15:33:31.160: E/AndroidRuntime(2570): at java.net.InetAddress.getAllByName(InetAddress.java:220)
01-02 15:33:31.160: E/AndroidRuntime(2570): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
01-02 15:33:31.160: E/AndroidRuntime(2570): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
01-02 15:33:31.160: E/AndroidRuntime(2570): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
01-02 15:33:31.160: E/AndroidRuntime(2570): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
01-02 15:33:31.160: E/AndroidRuntime(2570): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
01-02 15:33:31.160: E/AndroidRuntime(2570): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
01-02 15:33:31.160: E/AndroidRuntime(2570): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
01-02 15:33:31.160: E/AndroidRuntime(2570): at com.ggservice.democracy.JSONParser.getJSONFromUrl(JSONParser.java:38)
01-02 15:33:31.160: E/AndroidRuntime(2570): at com.ggservice.democracy.updateDemocracyService.onStartCommand(updateDemocracyService.java:47)
01-02 15:33:31.160: E/AndroidRuntime(2570): at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:2359)
01-02 15:33:31.160: E/AndroidRuntime(2570): ... 10 more
这也是服务：
public class updateDemocracyService extends Service{
private pollDataSource datasource;
int mStartMode; // indicates how to behave if the service is killed
IBinder mBinder; // interface for clients that bind
boolean mAllowRebind; // indicates whether onRebind should be used
// url to make request
private static String url = "http://www.test.com/democracy/domande.php";
// JSON Node names
private static final String TAG_DOMANDE = "domande";
private static final String TAG_ID = "id";
private static final String TAG_TESTO = "testo";
// contacts JSONArray
JSONArray contacts = null;
@Override
public void onCreate() {
// The service is being created
datasource = new pollDataSource(this);
datasource.open();
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
// Creating JSON Parser instance
JSONParser jParser = new JSONParser();
// getting JSON string from URL
JSONObject json = jParser.getJSONFromUrl(url);
try {
// Getting Array of Contacts
contacts = json.getJSONArray(TAG_DOMANDE);
// looping through All Contacts
for(int i = 0; i < contacts.length(); i++){
JSONObject c = contacts.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_ID);
String name = c.getString(TAG_TESTO);
datasource.createCategoria(name);
}
} catch (JSONException e) {
e.printStackTrace();
}
Toast.makeText(this, "ho comunicato con un server!", Toast.LENGTH_LONG).show();
return mStartMode;
}
@Override
public IBinder onBind(Intent intent) {
// A client is binding to the service with bindService()
return mBinder;
}
@Override
public boolean onUnbind(Intent intent) {
// All clients have unbound with unbindService()
return mAllowRebind;
}
@Override
public void onRebind(Intent intent) {
// A client is binding to the service with bindService(),
// after onUnbind() has already been called
}
@Override
public void onDestroy() {
datasource.close();
// The service is no longer used and is being destroyed
}
}
答案 0 :(得分：9)
这是因为您正在主线程上执行网络操作，而Android 3.0及更高版本不允许这样做。即使它在服务中，服务也在UI线程上运行，除非您在另一个线程中专门启动它们或在其中创建一个线程。
您可以通过使用Thread或AsyncTask在主UI线程中运行服务中的任务来解决此问题。
尝试在onStartCommand()中创建一个新线程，如@CommonsWare所示。
答案 1 :(得分：6)
创建功能：
Thread thread = new Thread(new Runnable(){
@Override
public void run() {
.......
}
});
从 onStartCommand
调用它thread.start();
答案 2 :(得分：3)
As per the documentation，即使您使用Service执行长时间运行操作，服务本身也会在应用程序的主线程上运行。因此，您必须生成一个新线程来执行可能长时间运行的任务，如网络访问。
Android StrictMode实际检查主线程上执行的网络操作并抛出NetworkOnMainThreadException。
答案 3 :(得分：1)