私のアプリでは、JSON の形式でサーバーからデータを取得しています。データは約 1.5 MB です。アプリは動作しますが、サーバーからデータをフェッチしているときにクラッシュし、OutOfMemoryError が発生することがあります。
これは私の方法です：
private String sendPostRequest(String url, List<NameValuePair> params)
throws Exception {
String ret = null;
BufferedReader bufferedReader = null;
HttpClient httpClient = new DefaultHttpClient();
HttpPost request = new HttpPost(url);
try {
UrlEncodedFormEntity entity = new UrlEncodedFormEntity(params);
request.setEntity(entity);
HttpResponse response = httpClient.execute(request);
bufferedReader = new BufferedReader(new InputStreamReader(response
.getEntity().getContent()));
StringBuilder stringBuilder = new StringBuilder("");
StringBuilder stringBuilder2;
String line = "";
//String LineSeparator = System.getProperty("line.separator");
while ((line = bufferedReader.readLine()) != null) {
stringBuilder.append(line);
}
bufferedReader.close();
ret = stringBuilder.toString();
stringBuilder = null;
} catch (ClientProtocolException e) {
e.printStackTrace();
// TODO: report an error
} catch (IOException e) {
e.printStackTrace();
// TODO: report an error
} finally {
if (bufferedReader != null) {
try {
bufferedReader.close();
} catch (IOException e) {
e.printStackTrace();
// TODO Auto-generated catch block
}
}
}
return ret;
}
使用後に StringBuilder を null に設定しようとしましたが、役に立ちませんでした。以下の logcat トレースを投稿しています。
10-23 03:39:25.271: E/dalvikvm-heap(1011): Out of memory on a 4116282-byte allocation.
10-23 03:39:25.271: I/dalvikvm(1011): "AsyncTask #1" prio=5 tid=11 RUNNABLE
10-23 03:39:25.271: I/dalvikvm(1011): | group="main" sCount=0 dsCount=0 obj=0x417c5e88 self=0x2a1d1db8
10-23 03:39:25.271: I/dalvikvm(1011): | sysTid=1025 nice=10 sched=0/0 cgrp=apps/bg_non_interactive handle=706552328
10-23 03:39:25.271: I/dalvikvm(1011): | state=R schedstat=( 3053328788 23773807212 6541 ) utm=241 stm=64 core=0
10-23 03:39:25.271: I/dalvikvm(1011): at java.lang.String.<init>(String.java:~422)
10-23 03:39:25.271: I/dalvikvm(1011): at java.lang.AbstractStringBuilder.toString(AbstractStringBuilder.java:642)
10-23 03:39:25.282: I/dalvikvm(1011): at java.lang.StringBuilder.toString(StringBuilder.java:663)
10-23 03:39:25.282: I/dalvikvm(1011): at com.dzo.redacted.driverapp.datalayer.ServerConnect.sendPostRequest(ServerConnect.java:128)
10-23 03:39:25.282: I/dalvikvm(1011): at com.dzo.redacted.driverapp.datalayer.ServerConnect.Sync(ServerConnect.java:61)
10-23 03:39:25.282: I/dalvikvm(1011): at com.dzo.redacted.driverapp.datalayer.DBSync.Login(DBSync.java:59)
10-23 03:39:25.282: I/dalvikvm(1011): at com.dzo.redacted.driverapp.asynctask.SyncDBTask.doInBackground(SyncDBTask.java:52)
10-23 03:39:25.282: I/dalvikvm(1011): at com.dzo.redacted.driverapp.asynctask.SyncDBTask.doInBackground(SyncDBTask.java:1)
10-23 03:39:25.282: I/dalvikvm(1011): at android.os.AsyncTask$2.call(AsyncTask.java:287)
10-23 03:39:25.282: I/dalvikvm(1011): at java.util.concurrent.FutureTask.run(FutureTask.java:234)
10-23 03:39:25.282: I/dalvikvm(1011): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
10-23 03:39:25.282: I/dalvikvm(1011): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
10-23 03:39:25.282: I/dalvikvm(1011): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
10-23 03:39:25.282: I/dalvikvm(1011): at java.lang.Thread.run(Thread.java:841)
10-23 03:39:25.282: W/dalvikvm(1011): threadid=11: thread exiting with uncaught exception (group=0x41465700)
10-23 03:39:25.292: I/Choreographer(1011): Skipped 30 frames! The application may be doing too much work on its main thread.
10-23 03:39:25.491: E/AndroidRuntime(1011): FATAL EXCEPTION: AsyncTask #1
10-23 03:39:25.491: E/AndroidRuntime(1011): java.lang.RuntimeException: An error occured while executing doInBackground()
10-23 03:39:25.491: E/AndroidRuntime(1011): at android.os.AsyncTask$3.done(AsyncTask.java:299)
10-23 03:39:25.491: E/AndroidRuntime(1011): at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
10-23 03:39:25.491: E/AndroidRuntime(1011): at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
10-23 03:39:25.491: E/AndroidRuntime(1011): at java.util.concurrent.FutureTask.run(FutureTask.java:239)
10-23 03:39:25.491: E/AndroidRuntime(1011): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
10-23 03:39:25.491: E/AndroidRuntime(1011): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
10-23 03:39:25.491: E/AndroidRuntime(1011): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
10-23 03:39:25.491: E/AndroidRuntime(1011): at java.lang.Thread.run(Thread.java:841)
10-23 03:39:25.491: E/AndroidRuntime(1011): Caused by: java.lang.OutOfMemoryError
10-23 03:39:25.491: E/AndroidRuntime(1011): at java.lang.String.<init>(String.java:422)
10-23 03:39:25.491: E/AndroidRuntime(1011): at java.lang.AbstractStringBuilder.toString(AbstractStringBuilder.java:642)
10-23 03:39:25.491: E/AndroidRuntime(1011): at java.lang.StringBuilder.toString(StringBuilder.java:663)
10-23 03:39:25.491: E/AndroidRuntime(1011): at com.dzo.redacted.driverapp.datalayer.ServerConnect.sendPostRequest(ServerConnect.java:128)
10-23 03:39:25.491: E/AndroidRuntime(1011): at com.dzo.redacted.driverapp.datalayer.ServerConnect.Sync(ServerConnect.java:61)
10-23 03:39:25.491: E/AndroidRuntime(1011): at com.dzo.redacted.driverapp.datalayer.DBSync.Login(DBSync.java:59)
10-23 03:39:25.491: E/AndroidRuntime(1011): at com.dzo.redacted.driverapp.asynctask.SyncDBTask.doInBackground(SyncDBTask.java:52)
10-23 03:39:25.491: E/AndroidRuntime(1011): at com.dzo.redacted.driverapp.asynctask.SyncDBTask.doInBackground(SyncDBTask.java:1)
10-23 03:39:25.491: E/AndroidRuntime(1011): at android.os.AsyncTask$2.call(AsyncTask.java:287)
10-23 03:39:25.491: E/AndroidRuntime(1011): at java.util.concurrent.FutureTask.run(FutureTask.java:234)
10-23 03:39:25.491: E/AndroidRuntime(1011): ... 4 more
10-23 03:39:28.091: E/WindowManager(1011): Activity com.dzo.redacted.driverapp.LoginActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{4178fcb0 V.E..... R.....ID 0,0-479,96} that was originally added here
10-23 03:39:28.091: E/WindowManager(1011): android.view.WindowLeaked: Activity com.dzo.redacted.driverapp.LoginActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{4178fcb0 V.E..... R.....ID 0,0-479,96} that was originally added here
10-23 03:39:28.091: E/WindowManager(1011): at android.view.ViewRootImpl.<init>(ViewRootImpl.java:345)
10-23 03:39:28.091: E/WindowManager(1011): at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:239)
10-23 03:39:28.091: E/WindowManager(1011): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69)
10-23 03:39:28.091: E/WindowManager(1011): at android.app.Dialog.show(Dialog.java:281)
10-23 03:39:28.091: E/WindowManager(1011): at com.dzo.redacted.driverapp.asynctask.SyncDBTask.onPreExecute(SyncDBTask.java:43)
10-23 03:39:28.091: E/WindowManager(1011): at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:586)
10-23 03:39:28.091: E/WindowManager(1011): at android.os.AsyncTask.execute(AsyncTask.java:534)
10-23 03:39:28.091: E/WindowManager(1011): at com.dzo.redacted.driverapp.asynctask.LoginAsyncTask.onPostExecute(LoginAsyncTask.java:87)
10-23 03:39:28.091: E/WindowManager(1011): at com.dzo.redacted.driverapp.asynctask.LoginAsyncTask.onPostExecute(LoginAsyncTask.java:1)
10-23 03:39:28.091: E/WindowManager(1011): at android.os.AsyncTask.finish(AsyncTask.java:631)
10-23 03:39:28.091: E/WindowManager(1011): at android.os.AsyncTask.access$600(AsyncTask.java:177)
10-23 03:39:28.091: E/WindowManager(1011): at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
10-23 03:39:28.091: E/WindowManager(1011): at android.os.Handler.dispatchMessage(Handler.java:99)
10-23 03:39:28.091: E/WindowManager(1011): at android.os.Looper.loop(Looper.java:137)
10-23 03:39:28.091: E/WindowManager(1011): at android.app.ActivityThread.main(ActivityThread.java:5103)
10-23 03:39:28.091: E/WindowManager(1011): at java.lang.reflect.Method.invokeNative(Native Method)
10-23 03:39:28.091: E/WindowManager(1011): at java.lang.reflect.Method.invoke(Method.java:525)
10-23 03:39:28.091: E/WindowManager(1011): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
10-23 03:39:28.091: E/WindowManager(1011): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
10-23 03:39:28.091: E/WindowManager(1011): at dalvik.system.NativeStart.main(Native Method)
10-23 03:44:25.761: I/Process(1011): Sending signal. PID: 1011 SIG: 9
更新 1
このアプローチをもう一度試してみましたが、私の場合も toString() でエラーが発生しました。toString() でエラーが発生しています。Amit's answerで試したときに同じことが起こりました。toString() には何かありますか。
更新 2
while ループから新しい String ビルダー オブジェクトの作成を削除し、現在は行区切りを使用していません。しかし、それは大きな違いはありませんでした。アプリは初めて実行されます。しかし、2～3回連続で走らせようとすると、また同じ問題が発生します。