发生异常,猜测是多线程同步问题

[Wanxp]

异常信息如下:

java.util.ConcurrentModificationException
	at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:909)
	at java.util.ArrayList$Itr.next(ArrayList.java:859)
	at cn.ieclipse.wechat.WXContactTreeNode.update(WXContactTreeNode.java:46)
	at cn.ieclipse.wechat.WXContactView.doUpdateContacts(WXContactView.java:128)
	at cn.ieclipse.smartim.views.IMContactView$4.run(IMContactView.java:94)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:764)
	at java.awt.EventQueue.access$500(EventQueue.java:98)
	at java.awt.EventQueue$3.run(EventQueue.java:715)
	at java.awt.EventQueue$3.run(EventQueue.java:709)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:734)
	at com.intellij.ide.IdeEventQueue.defaultDispatchEvent(IdeEventQueue.java:729)
	at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.java:678)
	at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:373)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:109)
	at java.awt.WaitDispatchSupport$2.run(WaitDispatchSupport.java:190)
	at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:235)
	at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:233)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.awt.WaitDispatchSupport.enter(WaitDispatchSupport.java:233)
	at java.awt.Dialog.show(Dialog.java:1077)
	at com.intellij.openapi.ui.impl.DialogWrapperPeerImpl$MyDialog.show(DialogWrapperPeerImpl.java:706)
	at com.intellij.openapi.ui.impl.DialogWrapperPeerImpl.show(DialogWrapperPeerImpl.java:437)
	at com.intellij.openapi.ui.DialogWrapper.invokeShow(DialogWrapper.java:1682)
	at com.intellij.openapi.ui.DialogWrapper.show(DialogWrapper.java:1631)
	at com.intellij.openapi.options.newEditor.SettingsDialog.lambda$show$0(SettingsDialog.java:73)
	at com.intellij.openapi.application.TransactionGuardImpl.runSyncTransaction(TransactionGuardImpl.java:88)
	at com.intellij.openapi.application.TransactionGuardImpl.submitTransactionAndWait(TransactionGuardImpl.java:153)
	at com.intellij.openapi.options.newEditor.SettingsDialog.show(SettingsDialog.java:73)
	at com.intellij.ide.actions.ShowSettingsUtilImpl.showSettingsDialog(ShowSettingsUtilImpl.java:84)
	at com.intellij.ide.actions.ShowSettingsAction.perform(ShowSettingsAction.java:54)
	at com.intellij.ide.actions.ShowSettingsAction.actionPerformed(ShowSettingsAction.java:41)
	at com.intellij.openapi.actionSystem.ex.ActionUtil$1.run(ActionUtil.java:261)
	at com.intellij.openapi.actionSystem.ex.ActionUtil.performActionDumbAware(ActionUtil.java:278)
	at com.intellij.openapi.keymap.impl.IdeKeyEventDispatcher$1.performAction(IdeKeyEventDispatcher.java:622)
	at com.intellij.openapi.keymap.impl.IdeKeyEventDispatcher.lambda$processAction$2(IdeKeyEventDispatcher.java:671)
	at com.intellij.openapi.application.TransactionGuardImpl.performUserActivity(TransactionGuardImpl.java:195)
	at com.intellij.openapi.keymap.impl.IdeKeyEventDispatcher.processAction(IdeKeyEventDispatcher.java:670)
	at com.intellij.openapi.keymap.impl.IdeKeyEventDispatcher.processActionOrWaitSecondStroke(IdeKeyEventDispatcher.java:518)
	at com.intellij.openapi.keymap.impl.IdeKeyEventDispatcher.inInitState(IdeKeyEventDispatcher.java:473)
	at com.intellij.openapi.keymap.impl.IdeKeyEventDispatcher.dispatchKeyEvent(IdeKeyEventDispatcher.java:223)
	at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.java:653)
	at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:373)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

具体异常位置ArrayList.java:909
的方法如下
位置为checkForComodification()方法位置抛出异常

        @Override
        @SuppressWarnings("unchecked")
        public void forEachRemaining(Consumer<? super E> consumer) {
            Objects.requireNonNull(consumer);
            final int size = ArrayList.this.size;
            int i = cursor;
            if (i >= size) {
                return;
            }
            final Object[] elementData = ArrayList.this.elementData;
            if (i >= elementData.length) {
                throw new ConcurrentModificationException();
            }
            while (i != size && modCount == expectedModCount) {
                consumer.accept((E) elementData[i++]);
            }
            // update once at end of iteration to reduce heap write traffic
            cursor = i;
            lastRet = i - 1;
            checkForComodification();
        }

        final void checkForComodification() {
            if (modCount != expectedModCount)
                throw new ConcurrentModificationException();
        }
    }