Java 异步任务Android中的多请求

我对Android中的异步任务有一些问题。因此，当单次点击映射时，它将通过在AsyncTask类中传递一个事件对象作为参数来执行该方法，以获得基于坐标X和Y的地址：

mMapView.setOnSingleTapListener(new OnSingleTapListener() {
        public void onSingleTap(float x, float y) {
            final Point point = mMapView.toMapPoint(x, y);
                eventModel.setEventX(String.valueOf(point.getX()));
                eventModel.setEventY(String.valueOf(point.getY()));
                 new MyAsyncTask(new MyAsyncTask.OnRoutineFinished() {
                        public void onFinish() {
                             CreateEvent.createEventDialog(context, point.getX(),
                                    point.getY(), eventAddress);  //this will be called after the task finishes
                        }
                    }).execute(eventModel);         
            }
    });
    new MyAsyncTask().execute();
}

MyAsyncTask类

public static class MyAsyncTask extends AsyncTask<Event, Integer, Double> {
    public interface OnRoutineFinished{  //interface
        void onFinish();
    }
    private OnRoutineFinished mCallbacks;
    public MyAsyncTask(OnRoutineFinished callback){ //constructor with interface
        mCallbacks = callback;
    }

    public MyAsyncTask(){} //empty constructor to maintain compatibility

    @Override
    protected Double doInBackground(Event... params) {

        try {
            eventAddress = eventCtrl.getStreetAddressFromGeometry(eventModel.getEventX(), eventModel.getEventY());
            eventCtrl.retrieveEventJSON();
            if (params.length == 1) {
                eventCtrl.createEvent(params[0]);   
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }

        return null;
    }

    protected void onPostExecute(Double result) {
        if(mCallbacks !=null)
            mCallbacks.onFinish(); //call interface on finish
    }

    protected void onProgressUpdate(Integer... progress) {
    }
}

一旦用户单击OK，它将通过servlet将DB插入MySQL。onConfirmAddEventClicked（）基本上是获取每个属性的所有用户输入和设置值，并作为事件对象返回

然而，我现在遇到的问题是，即使用户单击cancel，它仍然只使用坐标X和Y执行DB插入。我猜这是因为MyAsynctask中的if语句包含一个参数

当用户单击OK时，是否有任何方法仅执行DB插入？提前谢谢

编辑

mMapView.setOnSingleTapListener(new OnSingleTapListener() {
        private static final long serialVersionUID = 1L;

        public void onSingleTap(float x, float y) {
            final Point point = mMapView.toMapPoint(x, y);
                eventModel.setEventX(String.valueOf(point.getX()));
                eventModel.setEventY(String.valueOf(point.getY()));
                 new MyAsyncTask().execute(eventModel);         
            }
    });
    new MyAsyncTask().execute();
}

protected void onPostExecute(Double result) {
        if(mCallbacks !=null)
            mCallbacks.onFinish(); //call interface on finish
         CreateEvent.createEventDialog(context, Double.parseDouble(eventModel.getEventX()),
                    Double.parseDouble(eventModel.getEventY()), eventAddress);
    }

使用这些代码，我将收到以下错误消息：

11-11 21:41:29.457: D/dalvikvm(7062): GC_CONCURRENT freed 457K, 12% free 11022K/12423K, paused 74ms+124ms
11-11 21:41:34.074: D/dalvikvm(7062): GC_CONCURRENT freed 620K, 13% free 11021K/12551K, paused 56ms+237ms
11-11 21:41:37.589: D/dalvikvm(7062): GC_CONCURRENT freed 597K, 13% free 11018K/12615K, paused 29ms+7ms
11-11 21:41:39.441: D/AndroidRuntime(7062): Shutting down VM
11-11 21:41:39.441: W/dalvikvm(7062): threadid=1: thread exiting with uncaught exception (group=0x40c7e1f8)
11-11 21:41:39.464: E/AndroidRuntime(7062): FATAL EXCEPTION: main
11-11 21:41:39.464: E/AndroidRuntime(7062): java.lang.NullPointerException
11-11 21:41:39.464: E/AndroidRuntime(7062):     at java.lang.StringToReal.parseDouble(StringToReal.java:244)
11-11 21:41:39.464: E/AndroidRuntime(7062):     at java.lang.Double.parseDouble(Double.java:295)
11-11 21:41:39.464: E/AndroidRuntime(7062):     at nyp.edu.eneighbourhood.ENeighbourhoodActivity$MyAsyncTask.onPostExecute(ENeighbourhoodActivity.java:227)
11-11 21:41:39.464: E/AndroidRuntime(7062):     at nyp.edu.eneighbourhood.ENeighbourhoodActivity$MyAsyncTask.onPostExecute(ENeighbourhoodActivity.java:1)
11-11 21:41:39.464: E/AndroidRuntime(7062):     at android.os.AsyncTask.finish(AsyncTask.java:602)
11-11 21:41:39.464: E/AndroidRuntime(7062):     at android.os.AsyncTask.access$600(AsyncTask.java:156)
11-11 21:41:39.464: E/AndroidRuntime(7062):     at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:615)
11-11 21:41:39.464: E/AndroidRuntime(7062):     at android.os.Handler.dispatchMessage(Handler.java:99)
11-11 21:41:39.464: E/AndroidRuntime(7062):     at android.os.Looper.loop(Looper.java:137)
11-11 21:41:39.464: E/AndroidRuntime(7062):     at android.app.ActivityThread.main(ActivityThread.java:4512)
11-11 21:41:39.464: E/AndroidRuntime(7062):     at java.lang.reflect.Method.invokeNative(Native Method)
11-11 21:41:39.464: E/AndroidRuntime(7062):     at java.lang.reflect.Method.invoke(Method.java:511)
11-11 21:41:39.464: E/AndroidRuntime(7062):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:982)
11-11 21:41:39.464: E/AndroidRuntime(7062):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:749)
11-11 21:41:39.464: E/AndroidRuntime(7062):     at dalvik.system.NativeStart.main(Native Method)
11-11 21:41:56.082: I/dalvikvm(7062): threadid=3: reacting to signal 3
11-11 21:41:56.160: I/dalvikvm(7062): Wrote stack traces to '/data/anr/traces.txt'

---

我认为出现此错误是因为当用户重复键入时会有多个

AsyncTasks

运行

如果可能，尝试移动您的

对话框从
setPositiveButton
到
onPostExecute
。这样做将确保
对话框
在
异步任务
完成任务之前不会关闭，因此（我认为）将消除该错误

更新

我刚刚意识到您执行了两次AsyncTask：

mMapView.setOnSingleTapListener(new OnSingleTapListener() {
        public void onSingleTap(float x, float y) {
            final Point point = mMapView.toMapPoint(x, y);
                eventModel.setEventX(String.valueOf(point.getX()));
                eventModel.setEventY(String.valueOf(point.getY()));
                 new MyAsyncTask(new MyAsyncTask.OnRoutineFinished() {
                        public void onFinish() {
                             CreateEvent.createEventDialog(context, point.getX(),
                                    point.getY(), eventAddress);  //this will be called after the task finishes
                        }
                    }).execute(eventModel);  //1st       
            }
    });
    //new MyAsyncTask().execute(); //2nd, try to comment this
}

如果它仍然不起作用，请查看我的注释并尝试将
createEventDialog
移动到
onPostExecute
（不再需要使用
callback
和
onFInish
）
但是现在的问题就像我在地图上点击一次，它获取坐标X和Y，并立即执行eventCtrl.createEvent，而不是进入createEventDialog，仅在用户单击“确定”后执行（@IWasSoLost请查看我更新的答案。尝试通过仅使用1个asyncTask来简化代码我需要asyncTask在一次点击时获取地址并将其传递给createEventDialog尝试删除onFinish，将createEventDialog移动到onPostExecute…查看是否有任何不同我实际需要onFinish以便createDialogEvent将填充eventAddress。那么您有什么想法吗？想解释一下吗？
mMapView.setOnSingleTapListener(new OnSingleTapListener() {
        public void onSingleTap(float x, float y) {
            final Point point = mMapView.toMapPoint(x, y);
                eventModel.setEventX(String.valueOf(point.getX()));
                eventModel.setEventY(String.valueOf(point.getY()));
                 new MyAsyncTask(new MyAsyncTask.OnRoutineFinished() {
                        public void onFinish() {
                             CreateEvent.createEventDialog(context, point.getX(),
                                    point.getY(), eventAddress);  //this will be called after the task finishes
                        }
                    }).execute(eventModel);  //1st       
            }
    });
    //new MyAsyncTask().execute(); //2nd, try to comment this
}