我有一个带有扩展 AsyncTask 的私有类的 MyMapActivity，目的是在每次更改地图部分时（onMove() 方法）在服务器上进行请求。来自服务器的响应是 JSON 数据字符串，大小约为 1-3 MB。因此，当用户移动地图以避免 OutOfMemory 时，我需要避免多次调用服务器。出于这个原因，我试图检查我自己的 AsyncTask 是否被取消（在每次 onMove() 开始时），如果没有（我想这表明关于执行 doInBackground() 方法）我想取消它。但不管怎样，我仍然有一个
01-19 20:45:05.660: 错误/MapActivity(2482): 无法获取连接工厂客户端 01-19 20:45:40.600: ERROR/Tethering(96): active iface (usb0) 报告为添加，忽略 01-19 20:47:15.260: 错误/dalvikvm-heap(2482): 11908 字节分配内存不足。 01-19 20:47:15.270：错误/dalvikvm(2482)：内存不足：堆大小=24519KB，分配=23091KB，位图大小=101KB 01-19 20:47:15.410: 错误/dalvikvm-heap(2482): 7690 字节分配内存不足。 01-19 20:47:15.420：错误/dalvikvm（2482）：内存不足：堆大小=24519KB，分配=23088KB，位图大小=101KB 01-19 20:47:15.570：错误/dalvikvm-heap(2482)：7656 字节分配内存不足。 01-19 20:47:15.590：错误/dalvikvm（2482）：内存不足：堆大小=24519KB，分配=23090KB，位图大小=101KB 01-19 20:47:15.730: 错误/dalvikvm-heap(2482): 9098 字节分配内存不足。 01-19 20:47:15.740：错误/dalvikvm(2482)：内存不足：堆大小=24519KB，分配=23097KB，位图大小=101KB 01-19 20:48:01.850: 错误/dalvikvm-heap(2482): 8176 字节分配内存不足。 01-19 20:48:01.850：错误/dalvikvm(2482)：内存不足：堆大小=24519KB，分配=22767KB，位图大小=101KB 01-19 20:48:01.970: 错误/dalvikvm-heap(2482): 12022 字节分配内存不足。 01-19 20:48:01.980: 错误/dalvikvm(2482): 内存不足: 堆大小=24519KB, 分配=22768KB, 位图大小=101KB 01-19 20:48:02.110: 错误/dalvikvm-heap(2482): 8936 字节分配内存不足。 01-19 20:48:02.119：错误/dalvikvm(2482)：内存不足：堆大小=24519KB，分配=22769KB，位图大小=101KB 01-19 20:48:07.220: WARN/dalvikvm(2482): threadid=20: 线程以未捕获的异常退出 (group=0x400259f8) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 致命异常: AsyncTask #9 01-19 20:48:07.350: 错误/AndroidRuntime(2482): java.lang.RuntimeException: 执行 doInBackground() 时发生错误 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 android.os.AsyncTask$3.done(AsyncTask.java:200) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 java.util.concurrent.FutureTask.setException(FutureTask.java:124) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 java.util.concurrent.FutureTask.run(FutureTask.java:137) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1068) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:561) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 java.lang.Thread.run(Thread.java:1102) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 由: java.lang.OutOfMemoryError 引起 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 java.lang.String.(String.java:468) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 java.lang.AbstractStringBuilder.toString(AbstractStringBuilder.java:659) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 java.lang.StringBuilder.toString(StringBuilder.java:664) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 com.google.gson.stream.JsonReader.nextString(JsonReader.java:995) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 com.google.gson.stream.JsonReader.nextValue(JsonReader.java:810) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 com.google.gson.stream.JsonReader.objectValue(JsonReader.java:790) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 com.google.gson.stream.JsonReader.quickPeek(JsonReader.java:385) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 com.google.gson.stream.JsonReader.peek(JsonReader.java:348) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 com.google.gson.internal.bind.TypeAdapters$12.read(TypeAdapters.java:322) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 com.google.gson.internal.bind.TypeAdapters$12.read(TypeAdapters.java:334) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:86) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:170) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.read(TypeAdapterRuntimeTypeWrapper.java:38) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 com.google.gson.internal.bind.ArrayTypeAdapter.read(ArrayTypeAdapter.java:71) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:86) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:170) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 com.google.gson.Gson.fromJson(Gson.java:720) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 com.google.gson.Gson.fromJson(Gson.java:660) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 net.amagumo.realestate.MyMapActivity$MyTask.getHttpContent(MyMapActivity.java:444) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 net.amagumo.realestate.MyMapActivity$MyTask.doInBackground(MyMapActivity.java:393) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 net.amagumo.realestate.MyMapActivity$MyTask.doInBackground(MyMapActivity.java:1) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 android.os.AsyncTask$2.call(AsyncTask.java:185) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): 在 java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305) 01-19 20:48:07.350: 错误/AndroidRuntime(2482): ... 4 更多 01-19 20:48:07.450: WARN/ActivityManager(96): 强制完成活动 net.amagumo.realestate/.MyMapActivity 01-19 20:48:21.290: WARN/TimeThread(294): 转换时间失败 01-19 20:48:42.899: WARN/TimeThread(294): 转换时间失败
这是我的活动课：
public class MyMapActivity extends MapActivity implements LocationListener, OnTouchListener, OnMoveListener, MyMapItemClickedListener, DefaultActivity {
MyMapView mv;
MapController mc;
LocationManager lm;
MyItemizedOverlay myOverlay;
DatabaseAdapter db;
AdvertResult advertResult;
String callerActivityString;
MyTask mytask;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d(Constants.DEBUG_TAG, "MAP - create");
setContentView(R.layout.map);
db = new DatabaseAdapter(getApplicationContext()).open();
mv = (MyMapView)this.findViewById(R.id.mapView);
mc = mv.getController();
lm = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
mv.setOnTouchListener(this);
mv.setmOnMoveListener(this);
mv.setSatellite(true);
Drawable marker=getResources().getDrawable(R.drawable.ic_maps_indicator_startpoint_list);
int markerWidth = marker.getIntrinsicWidth();
int markerHeight = marker.getIntrinsicHeight();
marker.setBounds(0, markerHeight, markerWidth, 0);
myOverlay = new MyItemizedOverlay(marker);
myOverlay.setMyMapItemClickedListener(this);
mv.getOverlays().add(myOverlay);
advertResult = new AdvertResult();
mytask = new MyTask();
}
public void completeMap(){
Log.d(Constants.DEBUG_TAG_MAPS, "completing map - START");
for(AdvertSimple is : advertResult.getAdvertSimpleList()){
if(is.getAdress().getLat()!=null && is.getAdress().getLon()!=null){
GeoPoint gp = new GeoPoint(is.getAdress().getLat(), is.getAdress().getLon());
myOverlay.addItem(gp, "Advert", "snippet");
}
}
Log.d(Constants.DEBUG_TAG_MAPS, "completing map - END");
}
@Override
protected boolean isRouteDisplayed() {
return false;
}
public void onLocationChanged(Location loc) {
}
public void onProviderDisabled(String provider) {
}
public void onProviderEnabled(String provider) {
}
public void onStatusChanged(String provider, int status, Bundle extras) {
}
public boolean onTouch(View v, MotionEvent event) {
return false;
}
public void onMove(MapView mapView, GeoPoint center, boolean stopped) {
if(!mytask.isCancelled()){
Log.d(Constants.DEBUG_TAG_MAPS, "async task is cancelling - ATTEMPT");
mytask.cancel(true);
System.gc();
}
if(stopped){
Log.d(Constants.DEBUG_TAG_MAPS, "finished move/zoom action");
Integer latspan = mv.getLatitudeSpan();
Integer lonspan = mv.getLongitudeSpan();
Integer maxlat = center.getLatitudeE6() + (latspan/2);
Integer maxlon = center.getLongitudeE6() + (lonspan/2);
Integer minlat = center.getLatitudeE6() - (latspan/2);
Integer minlon = center.getLongitudeE6() - (lonspan/2);
mytask = new MyTask();
mytask.execute(this, null, new ResultComposite());
}
}
public MapRectangle getRectangle(){
GeoPoint center = mv.getMapCenter();
Integer latspan = mv.getLatitudeSpan();
Integer lonspan = mv.getLongitudeSpan();
Integer maxlat = center.getLatitudeE6() + (latspan/2);
Integer maxlon = center.getLongitudeE6() + (lonspan/2);
Integer minlat = center.getLatitudeE6() - (latspan/2);
Integer minlon = center.getLongitudeE6() - (lonspan/2);
return new MapRectangle(maxlat, maxlon, minlat, minlon);
}
@Override
public void completeAction(ResultComposite result) {
Log.d(Constants.DEBUG_TAG_MAPS, "async tasc is going to complete in caller activity - OK");
if(result!=null){
advertResult.setAdvertSimpleList(result.getAdvertSimpleList());
completeMap();
}
}
@Override
public RequestParams getRequestParams() {
RequestParams params = new RequestParams();
params.setDb(db);
params.setRectangle(getRectangle());
return params;
}
private class MyTask extends AsyncTask{
public MyMapActivity ma;
public HttpClient httpclient;
@Override
protected ResultComposite doInBackground(Object... params) {
Log.d(Constants.DEBUG_TAG_MAPS, "async tasc do in backgrounf - START");
ma = (MyMapActivity) params[0];
ResultComposite rc = new ResultComposite();
RequestParams rp = ma.getRequestParams();
MapRectangle rectangle = rp.getRectangle();
RequestJSONObject ro = new RequestJSONObject(rectangle.getMinlat(), rectangle.getMinlon(), rectangle.getMaxlat(), rectangle.getMaxlon());
Gson gson = new Gson();
String json = gson.toJson(ro);
ResponseJSONObject responseJSONObject = getHttpContent(json, Constants.HTTP_REQUEST_MAP);
AdvertSimpleJSON[] AdvertSimpleJSONarray = responseJSONObject.getAdvertySimple();
List simples = DataHelper.convertAdvertSimpleJSONArray2AdvertSimpleList(rp.getDb(), AdvertSimpleJSONarray);
rc.setAdvertSimpleList(simples);
return rc;
}
@Override
protected void onPostExecute(ResultComposite result) {
super.onPostExecute(result);
Log.d(Constants.DEBUG_TAG_MAPS, "async tasc is going to complete in caller activity - ATTEMPT");
ma.completeAction(result);
}
@Override
protected void onCancelled() {
super.onCancelled();
Log.d(Constants.DEBUG_TAG_MAPS, "async task is cancelling - OK");
}
private ResponseJSONObject getHttpContent(String json, String requestType){
ResponseJSONObject responseJSONObject = null;
HttpPost post = new HttpPost(Constants.SERVER_MAP_URL);
try {
Log.d(Constants.DEBUG_TAG_MAPS, "try");
HttpEntity entity = new StringEntity(json);
post.setEntity(entity);
HttpParams httpParameters = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(httpParameters, 15000);
HttpConnectionParams.setSoTimeout(httpParameters, 150000);
httpclient = new DefaultHttpClient(httpParameters);
BasicHttpResponse response = (BasicHttpResponse ) httpclient.execute(post);
if(response.getStatusLine().getStatusCode() == 200){
Log.d(Constants.DEBUG_TAG, "response 200");
HttpEntity responseEntity = response.getEntity();
Gson g = new Gson();
BufferedReader reader = new BufferedReader ( new InputStreamReader ( responseEntity.getContent()) );
responseJSONObject = g.fromJson(reader, ResponseJSONObject.class);
reader.close();
System.gc();
}
} catch (Exception e) {
e.printStackTrace();
}
Log.d(Constants.DEBUG_TAG_MAPS, "returning http results");
return responseJSONObject;
}
}
}
我还应该做什么？我试图执行消费 http 实体。
我处理 AsynTask 的逻辑是否正确？