Question

在我的一个Android应用中，我使用单例类来管理InApp结算。在这个课程中，我使用接口列表来通知来自InApp计费服务器的响应。

由于我的应用程序是多线程的，我希望这个列表能够同步，所以我已经完成了这个：

public class InAppPurchasesManager {
    ...
    private List<InAppPurchasesInterface> requestProductsListeners;
    ...
    public static InAppPurchasesManager getInstance() {

        if (mInstance == null) {
            mInstance = new InAppPurchasesManager();
        }
        return mInstance;
    }

    private InAppPurchasesManager() {}

    public void initInAppPurchasesManager(Application app) {
        ctxt = app.getApplicationContext();
        mInstance.requestProductsListeners = Collections.synchronizedList(new ArrayList());
    }
    ...
    public void addRequestProductListener(InAppPurchasesInterface listener)
    {
        synchronized(requestProductsListeners)
        {
            if(!requestProductsListeners.contains(listener))
                requestProductsListeners.add(listener);
        }
    }

    public void removeRequestProductListener(InAppPurchasesInterface listener)
    {
        synchronized(requestProductsListeners)
        {
            requestProductsListeners.remove(listener);
        }
    }

    private void responseOnRequestProductsAndPurchase(boolean success)
    {
        callingIabHelper = false;
        synchronized(requestProductsListeners)
        {
            for(InAppPurchasesInterface listener : requestProductsListeners)
                listener.onRequestProductsAndPurchased(success);
            return;
        }
    }
    ...
    public interface InAppPurchasesInterface {

        void onServiceStarted(boolean success);
        void onRequestProductsAndPurchased(boolean success);
        void onRequestProductPurchased(Purchase purchase, int error);

    }

}

但由于并发访问requestProductListeners，我仍然收到很多崩溃。

这是一个崩溃样本：

Fatal Exception: java.util.ConcurrentModificationException
       at java.util.ArrayList$ArrayListIterator.next(ArrayList.java:573)
       at com.mypackage.managers.InAppPurchasesManager.responseOnRequestProductsAndPurchase(InAppPurchasesManager.java:173)
       at com.mypackage.managers.InAppPurchasesManager.access$100(InAppPurchasesManager.java:24)
       at com.mypackage.managers.InAppPurchasesManager$2.onQueryInventoryFinished(InAppPurchasesManager.java:145)
       at com.mypackage.auxiliary.inappbilling.IabHelper$2$1.run(IabHelper.java:741)
       at android.os.Handler.handleCallback(Handler.java:739)
       at android.os.Handler.dispatchMessage(Handler.java:95)
       at android.os.Looper.loop(Looper.java:148)
       at android.app.ActivityThread.main(ActivityThread.java:7329)
       at java.lang.reflect.Method.invoke(Method.java)
       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)

由于我不是同步和多线程的专家，我确定我做错了什么。这些问题的任何解决方案是否有效？ https://stackoverflow.com/a/2120409

也许添加＆＃34;同步＆＃34;到使用requestProductsListeners的方法的定义？

编辑：我终于添加了同步但崩溃的原因是＆＃34; java.util.ConcurrentModificationException＆＃34;继续出现。

这是我现在的代码：

public class InAppPurchasesManager {
    ...
    private List<InAppPurchasesInterface> requestProductsListeners;
    ...
    public static InAppPurchasesManager getInstance() {

        if (mInstance == null) {
            mInstance = new InAppPurchasesManager();
        }
        return mInstance;
    }

    private InAppPurchasesManager() {}

    public void initInAppPurchasesManager(Application app) {
        ctxt = app.getApplicationContext();
        mInstance.requestProductsListeners = Collections.synchronizedList(new ArrayList());
    }
    ...
    public synchronized void addRequestProductListener(InAppPurchasesInterface listener)
    {
        synchronized(requestProductsListeners)
        {
            if(!requestProductsListeners.contains(listener))
                requestProductsListeners.add(listener);
        }
    }

    public synchronized void removeRequestProductListener(InAppPurchasesInterface listener)
    {
        synchronized(requestProductsListeners)
        {
            requestProductsListeners.remove(listener);
        }
    }

    private synchronized void responseOnRequestProductsAndPurchase(boolean success)
    {
        callingIabHelper = false;
        synchronized(requestProductsListeners)
        {
            for(InAppPurchasesInterface listener : requestProductsListeners)
                listener.onRequestProductsAndPurchased(success);
            return;
        }
    }
    ...
    public interface InAppPurchasesInterface {

        void onServiceStarted(boolean success);
        void onRequestProductsAndPurchased(boolean success);
        void onRequestProductPurchased(Purchase purchase, int error);

    }

}

我错过了什么？

编辑2：

要回答Maxim Blumental的评论，我添加以下信息：

addRequestProductListener方法（在数组中添加一个监听器）在OnResume（）方法中调用一些需要产品及其价格的片段。
一旦Google发送了有关产品及其价格的信息，就会调用responseOnRequestProductsAndPurchase方法（遍历调用回调的侦听器数组）。
一旦刚刚提到的回调结束，就会调用removeRequestProductListener方法（从数组中删除监听器）。

仅在

中调用initInAppPurchasesManager

public class MyApp extends MultiDexApplication {
@Override
public void onCreate() {
    super.onCreate();
     InAppPurchasesManager.getInstance().initInAppPurchasesManager(this);
}

Android同步无效

0 个答案: