未修改集合時引發Java ConcurrentModificationException

我在ArrayList上做了一個非常簡單的「過濾器」，偶爾拋出一個ConcurrentModifificationException，但AFAICT沒有修改發生......代碼非常簡單...未修改集合時引發Java ConcurrentModificationException

public ArrayList<JSONObject> getContributionsByInstallation(int installationID, ArrayList<JSONObject> list){ 
    ArrayList<JSONObject> filtered = new ArrayList<JSONObject>(); 
    for(JSONObject object : list) { 
     try { 
      int fk = object.getInt("exhibit_fk"); 
      if(fk == installationID){ 
       filtered.add(object); 
      } 
     } catch(JSONException e){ 

     } 
    } 
    return filtered; 
}

我錯過了什麼？

/編輯：將堆棧跟蹤

07-12 12:39:24.135: E/AndroidRuntime(2350): FATAL EXCEPTION: main 
07-12 12:39:24.135: E/AndroidRuntime(2350): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.whatever.light/com.whatever.light.InstallationDetailActivity}: java.util.ConcurrentModificationException 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1651) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1667) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at android.app.ActivityThread.access$1500(ActivityThread.java:117) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:935) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at android.os.Handler.dispatchMessage(Handler.java:99) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at android.os.Looper.loop(Looper.java:130) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at android.app.ActivityThread.main(ActivityThread.java:3691) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at java.lang.reflect.Method.invokeNative(Native Method) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at java.lang.reflect.Method.invoke(Method.java:507) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:907) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:665) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at dalvik.system.NativeStart.main(Native Method) 
07-12 12:39:24.135: E/AndroidRuntime(2350): Caused by: java.util.ConcurrentModificationException 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at java.util.ArrayList$ArrayListIterator.next(ArrayList.java:576) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at com.whatever.light.data.ContributionsData.getContrubtionsByInstallation(ContributionsData.java:81) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at com.whatever.light.data.ContributionsData.getRandomCommentContribution(ContributionsData.java:62) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at com.whatever.light.installations.ContributeCommentModuleFragment.showComment(ContributeCommentModuleFragment.java:102) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at com.whatever.light.installations.ContributeCommentModuleFragment.onCreateView(ContributeCommentModuleFragment.java:86) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:844) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1053) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:622) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1371) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:499) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1129) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at android.app.Activity.performStart(Activity.java:3817) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1624) 
07-12 12:39:24.135: E/AndroidRuntime(2350):  ... 11 more

來源

2012-07-12 momo

你能粘貼你的堆棧跟蹤嗎？ – 2012-07-12 17:50:26

似乎通過ArrayList 列表被迭代時由另一個線程修改，您應該使用'新ArrayList （列表）;' – s106mo 2012-07-12 17:50:58

[看這裏]（http://stackoverflow.com/questions/993025/ java-adding-elements-to-a-collection-during-iteration） – 2012-07-12 17:52:28