libgdx facebook sdk NoClassDefFoundError

Question

我在尝试在我的libgdx项目中添加Facebook登录功能时不断获得NoClassDefFoundError。

java.lang.NoClassDefFoundError: com.facebook.LoggingBehavior[]
        at com.facebook.FacebookSdk.<clinit>(FacebookSdk.java:63)
        at com.example.app.android.AndroidLauncher.onCreate(AndroidLauncher.java:44)
        at android.app.Activity.performCreate(Activity.java:5231)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2148)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)
        at android.app.ActivityThread.access$800(ActivityThread.java:135)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:136)
        at android.app.ActivityThread.main(ActivityThread.java:5001)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:515)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
        at dalvik.system.NativeStart.main(Native Method)

我在build.gradle中有。

compile "com.facebook.android:facebook-android-sdk:4.9.0"

从AndroidLauncher内部我可以引用此jar中的类

FacebookSdk.sdkInitialize(getApplicationContext());
callbackManager = CallbackManager.Factory.create();

甚至是假设缺失的那个，主要是LoggingBehavior，并且仍然没有充分的理由在运行时该类不存在。