我有一个MyMapActivity，其私有类扩展了AsyncTask，以便每次更改map部分时在服务器上执行请求（onMove（）方法）。来自服务器的响应是JSON数据字符串，大约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（在每个onMove（）开始），如果没有（我想这表明执行doInBackground（）方法）我想要取消它。但无论如何我仍然有一个
01-19 20:45:05.660: ERROR/MapActivity(2482): Couldn't get connection factory client 01-19 20:45:40.600: ERROR/Tethering(96): active iface (usb0) reported as added, ignoring 01-19 20:47:15.260: ERROR/dalvikvm-heap(2482): Out of memory on a 11908-byte allocation. 01-19 20:47:15.270: ERROR/dalvikvm(2482): Out of memory: Heap Size=24519KB, Allocated=23091KB, Bitmap Size=101KB 01-19 20:47:15.410: ERROR/dalvikvm-heap(2482): Out of memory on a 7690-byte allocation. 01-19 20:47:15.420: ERROR/dalvikvm(2482): Out of memory: Heap Size=24519KB, Allocated=23088KB, Bitmap Size=101KB 01-19 20:47:15.570: ERROR/dalvikvm-heap(2482): Out of memory on a 7656-byte allocation. 01-19 20:47:15.590: ERROR/dalvikvm(2482): Out of memory: Heap Size=24519KB, Allocated=23090KB, Bitmap Size=101KB 01-19 20:47:15.730: ERROR/dalvikvm-heap(2482): Out of memory on a 9098-byte allocation. 01-19 20:47:15.740: ERROR/dalvikvm(2482): Out of memory: Heap Size=24519KB, Allocated=23097KB, Bitmap Size=101KB 01-19 20:48:01.850: ERROR/dalvikvm-heap(2482): Out of memory on a 8176-byte allocation. 01-19 20:48:01.850: ERROR/dalvikvm(2482): Out of memory: Heap Size=24519KB, Allocated=22767KB, Bitmap Size=101KB 01-19 20:48:01.970: ERROR/dalvikvm-heap(2482): Out of memory on a 12022-byte allocation. 01-19 20:48:01.980: ERROR/dalvikvm(2482): Out of memory: Heap Size=24519KB, Allocated=22768KB, Bitmap Size=101KB 01-19 20:48:02.110: ERROR/dalvikvm-heap(2482): Out of memory on a 8936-byte allocation. 01-19 20:48:02.119: ERROR/dalvikvm(2482): Out of memory: Heap Size=24519KB, Allocated=22769KB, Bitmap Size=101KB 01-19 20:48:07.220: WARN/dalvikvm(2482): threadid=20: thread exiting with uncaught exception (group=0x400259f8) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): FATAL EXCEPTION: AsyncTask #9 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): java.lang.RuntimeException: An error occured while executing doInBackground() 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at android.os.AsyncTask$3.done(AsyncTask.java:200) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at java.util.concurrent.FutureTask.setException(FutureTask.java:124) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at java.util.concurrent.FutureTask.run(FutureTask.java:137) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1068) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:561) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at java.lang.Thread.run(Thread.java:1102) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): Caused by: java.lang.OutOfMemoryError 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at java.lang.String.(String.java:468) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at java.lang.AbstractStringBuilder.toString(AbstractStringBuilder.java:659) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at java.lang.StringBuilder.toString(StringBuilder.java:664) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at com.google.gson.stream.JsonReader.nextString(JsonReader.java:995) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at com.google.gson.stream.JsonReader.nextValue(JsonReader.java:810) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at com.google.gson.stream.JsonReader.objectValue(JsonReader.java:790) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at com.google.gson.stream.JsonReader.quickPeek(JsonReader.java:385) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at com.google.gson.stream.JsonReader.peek(JsonReader.java:348) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at com.google.gson.internal.bind.TypeAdapters$12.read(TypeAdapters.java:322) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at com.google.gson.internal.bind.TypeAdapters$12.read(TypeAdapters.java:334) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:86) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:170) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.read(TypeAdapterRuntimeTypeWrapper.java:38) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at com.google.gson.internal.bind.ArrayTypeAdapter.read(ArrayTypeAdapter.java:71) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:86) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:170) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at com.google.gson.Gson.fromJson(Gson.java:720) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at com.google.gson.Gson.fromJson(Gson.java:660) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at net.amagumo.realestate.MyMapActivity$MyTask.getHttpContent(MyMapActivity.java:444) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at net.amagumo.realestate.MyMapActivity$MyTask.doInBackground(MyMapActivity.java:393) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at net.amagumo.realestate.MyMapActivity$MyTask.doInBackground(MyMapActivity.java:1) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at android.os.AsyncTask$2.call(AsyncTask.java:185) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305) 01-19 20:48:07.350: ERROR/AndroidRuntime(2482): ... 4 more 01-19 20:48:07.450: WARN/ActivityManager(96): Force finishing activity net.amagumo.realestate/.MyMapActivity 01-19 20:48:21.290: WARN/TimeThread(294): conver time failed 01-19 20:48:42.899: WARN/TimeThread(294): conver time failed
这是我的活动课程：
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;
}
}
}
我还应该怎么办？我试图执行消耗http实体。
处理AsynTask的逻辑是否正确？