非法状态异常 AsyncTask MediaPlayer

Illegal State Exception AsyncTask MediaPlayer

我有两个正在更新媒体播放器和搜索栏的 AsyncTask。第一个是调用 runOnUIThread。当我调用第二个异步任务来更新媒体播放器时,我得到 IllegalStateException。日志如下。我该如何解决这个问题?

07-02 08:15:13.786  18990-18990/horatiothomas.com.spotify E/AndroidRuntime﹕ FATAL EXCEPTION: main
    java.lang.IllegalStateException
            at android.media.MediaPlayer._setDataSource(Native Method)
            at android.media.MediaPlayer.setDataSource(MediaPlayer.java:976)
            at android.media.MediaPlayer.setDataSource(MediaPlayer.java:929)
            at horatiothomas.com.spotify.ui.TrackPlayerActivityFragment$SwitchTrackPlayerTask.success(TrackPlayerActivityFragment.java:260)
            at horatiothomas.com.spotify.ui.TrackPlayerActivityFragment$SwitchTrackPlayerTask.success(TrackPlayerActivityFragment.java:238)
            at retrofit.CallbackRunnable.run(CallbackRunnable.java:45)
            at android.os.Handler.handleCallback(Handler.java:730)
            at android.os.Handler.dispatchMessage(Handler.java:92)
            at android.os.Looper.loop(Looper.java:137)
            at android.app.ActivityThread.main(ActivityThread.java:5103)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:525)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
            at dalvik.system.NativeStart.main(Native Method)

我需要在我的媒体播放器上调用 reset()。

Media Player 尚未准备好或它仍为空,您正在尝试使用它。