同步LinkedList时报错

代码：

private List<String> requests = Collections.synchronizedList(new LinkedList<String>());

和

private List<String> requests = Collections.synchronizedList(new LinkedList<String>());

运行报错：

FATAL EXCEPTION: main
java.lang.IllegalStateException: Could not execute method of the activity
    at android.view.View$1.onClick(View.java:2144)
    at android.view.View.performClick(View.java:2485)
    at android.view.View$PerformClick.run(View.java:9080)
    at android.os.Handler.handleCallback(Handler.java:587)
    at android.os.Handler.dispatchMessage(Handler.java:92)
    at android.os.Looper.loop(Looper.java:123)
    at android.app.ActivityThread.main(ActivityThread.java:3683)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:507)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
    at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.reflect.InvocationTargetException
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:507)
    at android.view.View$1.onClick(View.java:2139)
    ... 11 more
Caused by: java.lang.ClassCastException: java.util.Collections$SynchronizedList
    at com.countryst.nabard.turnbased.client.networking.ClientNetworking.login(ClientNetworking.java:72)
    at com.countryst.nabard.turnbased.client.MainActivity.loginToServer(MainActivity.java:87)
    at com.countryst.nabard.turnbased.client.MainActivity.onButtonClicked(MainActivity.java:217)
    ... 14 more

这个错误消息表明在您的代码中第72行，第87行和第217行有一个类转换异常。具体来说，您正在尝试将java.util.Collections$SynchronizedList转换为其他类型。这通常是由于在使用对象时使用了错误的数据类型或引用导致的。请检查这些行的代码，确保您正在使用正确的类型并重新检查您的代码。