长期运行后Volley在应用程序上崩溃 [英] Volley crashing app on service after long run
问题描述
Am正在实施一项服务，以从服务器获取更新，如下所示:
Am implementing a service to get updates from server as below:
public class Myupdates extends Service {
private static final String TAG = "AutoUpdates";
private static final int started = 0;
static SQLiteDatabase db;
private boolean isRunning = false;
private CountDownTimer timer;
@Override
public void onCreate() {
this.db = openOrCreateDatabase("db", Context.MODE_PRIVATE, null);
//Log.i(TAG, "Service onCreate");
isRunning = true;
}
int mCount = 1;
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
//Log.i(TAG, "Service onStartCommand");
//Creating new thread for my service
//Always write your long running tasks in a separate thread, to avoid ANR
new Thread(new Runnable() {
@Override
public void run() {
if (isRunning) {
new Timer().scheduleAtFixedRate(new TimerTask() {
@Override
public void run() {
updates();
}
}, 0, 30000);
}
//Stop service once it finishes its task
//stopSelf();
}
}).start();
return Service.START_STICKY;
}
@Override
public IBinder onBind(Intent arg0) {
//Log.i(TAG, "Service onBind");
return null;
}
@Override
public void onDestroy() {
isRunning = false;
//Log.i(TAG, "Service onDestroy");
}
/*
HANDLE ADVERTS
*/
protected void updates() {
/*
JSON
*/
final JSONObject json = new JSONObject();
final JSONObject manJson = new JSONObject();
try {
manJson.put("userid", "4444");
manJson.put("version", "6.0");
final String j = json.put("UPDATE", manJson).toString();
final String base_url = "https://myweburl.com";
// Instantiate the RequestQueue.
RequestQueue queue = Volley.newRequestQueue(this);
// Request a string response from the provided URL.
StringRequest stringRequest = new StringRequest(Request.Method.POST, base_url, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
//Log.i(TAG, "received "+response);
try {
JSONObject object = (JSONObject) new JSONTokener(response).nextValue();
String update = object.getString("UPDATE");
} catch (JSONException e) {
return;
}
return;
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
//perform operation here after getting error
return;
}
}) {
@Override
protected Map<String, String> getParams() {
Map<String, String> params = new HashMap<String, String>();
//pack message into json
try {
params.put("data", j.toString());
} catch (Exception e) {
//Log.i(TAG,"Map error: Unable to compile post");
}
return params;
}
@Override
public Map<String, String> getHeaders() throws AuthFailureError {
Map<String, String> params = new HashMap<String, String>();
params.put("Content-Type", "application/x-www-form-urlencoded");
return params;
}
};
// Add the request to the RequestQueue.
queue.add(stringRequest);
// ends here
return;
} catch (Exception e) {
//Log.i(TAG,"ERROR: Unable to get setup settings");
} // end exception write
return;
}
}
但是，长时间运行该服务后，应用崩溃了，并显示以下错误:
However, after a long running of the service the app is crashing with the below error:
03-08 00:19:41.570 11239-11253/com.mobiledatabook.com.dialcode E/AndroidRuntime:致命异常:Timer-0 流程:com.mobiledatabook.com.dialcode，PID:11239 java.lang.OutOfMemoryError:pthread_create(堆栈大小16384字节) 失败:再试一次 在java.lang.VMThread.create(本机方法) 在java.lang.Thread.start(Thread.java:1029) 在com.android.volley.RequestQueue.start(RequestQueue.java:152) 在com.android.volley.toolbox.Volley.newRequestQueue(Volley.java:66) 在com.android.volley.toolbox.Volley.newRequestQueue(Volley.java:78) 在 com.mobiledatabook.com.dialcode.Myupdates.iDialAutoUpdates(Myupdates.java:128) 在 com.mobiledatabook.com.dialcode.Myupdates $ 1 $ 1.run(Myupdates.java:74) 在java.util.Timer $ TimerImpl.run(Timer.java:284)
03-08 00:19:41.570 11239-11253/com.mobiledatabook.com.dialcode E/AndroidRuntime: FATAL EXCEPTION: Timer-0 Process: com.mobiledatabook.com.dialcode, PID: 11239 java.lang.OutOfMemoryError: pthread_create (stack size 16384 bytes) failed: Try again at java.lang.VMThread.create(Native Method) at java.lang.Thread.start(Thread.java:1029) at com.android.volley.RequestQueue.start(RequestQueue.java:152) at com.android.volley.toolbox.Volley.newRequestQueue(Volley.java:66) at com.android.volley.toolbox.Volley.newRequestQueue(Volley.java:78) at com.mobiledatabook.com.dialcode.Myupdates.iDialAutoUpdates(Myupdates.java:128) at com.mobiledatabook.com.dialcode.Myupdates$1$1.run(Myupdates.java:74) at java.util.Timer$TimerImpl.run(Timer.java:284)
错误:java.lang.OutOfMemoryError.
Error: java.lang.OutOfMemoryError.
有人可以帮助我改善此代码，以避免长时间运行该服务后使应用程序崩溃吗?
Could someone help me to improve this code so as to avoid crashing the app after long running of the service?
推荐答案
之所以发生这种情况，是因为您通过传递活动context多次创建了RequestQueue实例.您应该使用Application类创建一次实例，然后在需要时再次使用它.创建这样的应用程序类，
This is occurring because you are creating the RequestQueue instance multiple times by passing the activity context. You should create the instance once using an Application class and then use it again and again whenever needed. Create an application class like this,
public class AppController extends Application {
private static AppController sInstance;
private RequestQueue mRequestQueue;
@Override
public void onCreate() {
super.onCreate();
sInstance = this;
}
public static synchronized AppController getInstance() {
return sInstance;
}
public RequestQueue getRequestQueue() {
if (mRequestQueue == null) {
mRequestQueue = Volley.newRequestQueue(getApplicationContext());
}
return mRequestQueue;
}
}
然后像这样使用它
RequestQueue queue=AppController.getInstance().getRequestQueue();
注意:通过将上下文一次又一次传递给请求队列，您正在填充ram，这导致在无法分配更多空间时出现OutOfMemoryException
NOTE : By passing the context to request queue again and again , you are filling up your ram, which leads to an OutOfMemoryException when no more space can be allocated
如android的官方文档所述此处，
As mentioned in android's official docs here ,
一个关键概念是，必须使用Application上下文而不是Activity上下文实例化RequestQueue.这样可以确保RequestQueue持续到应用程序的整个生命周期，而不是每次重新创建活动(例如，当用户旋转设备时)都重新创建.
A key concept is that the RequestQueue must be instantiated with the Application context, not an Activity context. This ensures that the RequestQueue will last for the lifetime of your app, instead of being recreated every time the activity is recreated (for example, when the user rotates the device).
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