java.lang.IllegalStateException：不在主线程上

当服务器端制造商的表中没有可用数据并且数据对象为空时，我试图从 FragmentActivity 地图中的 Goolge 地图中删除标记，但我收到以下错误。我该如何修复它？

Error:

07-12 20:53:05.697: E/AndroidRuntime(26364): FATAL EXCEPTION: IntentService[IntentService]
07-12 20:53:05.697: E/AndroidRuntime(26364): Process: com.bustracker, PID: 26364
07-12 20:53:05.697: E/AndroidRuntime(26364): java.lang.IllegalStateException: Not on the main thread
07-12 20:53:05.697: E/AndroidRuntime(26364):    at com.google.l.a.ce.b(Unknown Source)
07-12 20:53:05.697: E/AndroidRuntime(26364):    at com.google.maps.api.android.lib6.d.ct.a(Unknown Source)
07-12 20:53:05.697: E/AndroidRuntime(26364):    at com.google.maps.api.android.lib6.d.aq.a(Unknown Source)
07-12 20:53:05.697: E/AndroidRuntime(26364):    at com.google.android.gms.maps.model.internal.t.onTransact(SourceFile:51)
07-12 20:53:05.697: E/AndroidRuntime(26364):    at android.os.Binder.transact(Binder.java:380)
07-12 20:53:05.697: E/AndroidRuntime(26364):    at com.google.android.gms.maps.model.internal.zzi$zza$zza.remove(Unknown Source)
07-12 20:53:05.697: E/AndroidRuntime(26364):    at com.google.android.gms.maps.model.Marker.remove(Unknown Source)
07-12 20:53:05.697: E/AndroidRuntime(26364):    at com.bustracker.GetLLRD.onHandleIntent(GetLLRD.java:120)
07-12 20:53:05.697: E/AndroidRuntime(26364):    at android.app.IntentService$ServiceHandler.handleMessage(IntentService.java:65)
07-12 20:53:05.697: E/AndroidRuntime(26364):    at android.os.Handler.dispatchMessage(Handler.java:102)
07-12 20:53:05.697: E/AndroidRuntime(26364):    at android.os.Looper.loop(Looper.java:145)
07-12 20:53:05.697: E/AndroidRuntime(26364):    at android.os.HandlerThread.run(HandlerThread.java:61)

GetLLRD IntentService 类中的 onHandleIntent 方法：

protected void onHandleIntent(Intent intent) {

                            if (data != null && !data.isEmpty()) {
                                Intent intent1 = new Intent(this, Map.class);
                                intent1.putExtra("list_data", data);
                                intent1.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK
                                        | Intent.FLAG_ACTIVITY_SINGLE_TOP);
                                startActivity(intent1);

                            } else if (Map.markerMap != null
                                    && !Map.markerMap.isEmpty()) {

                                Iterator<HashMap.Entry<Integer, Marker>> it = Map.markerMap
                                        .entrySet().iterator();
                                while (it.hasNext()) {
                                    HashMap.Entry<Integer, Marker> entery = it
                                            .next();
                                    int key = entery.getKey();
                                    Map.marker = Map.markerMap.get(key);
                                    System.out.println("test marker " + Map.marker ); 
                                    //Line 120.
                                    Map.marker .remove();
                                    Map.markerMap.remove(key);

                                    // Marker value = entery.getValue();
                                }
                            }

映射fragmentActivity：

public class Map extends FragmentActivity implements OnMapReadyCallback {

    GoogleMap map;
    static HashMap<Integer, Marker> markerMap = new HashMap<Integer, Marker>();
    static Marker marker = null;

    ...
    }

解决该异常的一个快速方法是将地图更新放入Runnable在主线程上执行（代码如下）。然而，问题的真正答案是您需要重新思考您的设计。中的代码是不安全的IntentService在活动中使用静态数据。使用a的原因有哪些IntentService？地图更新必须在主线程上运行。的目的之一是IntentService是执行以下操作cannot在主线程上完成，并且需要一个后台线程。为什么要使用IntentService当它包含需要主线程的代码时？

    new Handler(Looper.getMainLooper()).post(new Runnable() {
        @Override
        public void run() {
            Iterator<HashMap.Entry<Integer, Marker>> it = Map.markerMap
                    .entrySet().iterator();
            while (it.hasNext()) {
                HashMap.Entry<Integer, Marker> entery = it
                        .next();
                int key = entery.getKey();
                Map.marker = Map.markerMap.get(key);
                System.out.println("test marker " + Map.marker );
                //Line 120.
                Map.marker.remove();
                // Remove from map using iterator
                it.remove();

                // Marker value = entery.getValue();
            }
        }
    });