NoClassDefFoundError: org.slf4j.LoggerFactory

java.lang.NoClassDefFoundError: org.slf4j.LoggerFactory
at com.danikula.videocache.HttpProxyCacheServer.(HttpProxyCacheServer.java:54)
at cn.youbeitong.smart.MApplication.newProxy(MApplication.java:113)
at cn.youbeitong.smart.MApplication.getProxy(MApplication.java:109)
at cn.youbeitong.smart.activity.VideoPlayActivity.setVideoPlay(VideoPlayActivity.java:335)
at cn.youbeitong.smart.activity.VideoPlayActivity.init(VideoPlayActivity.java:227)
at cn.youbeitong.smart.activity.VideoPlayActivity.initDatas(VideoPlayActivity.java:203)
at cn.youbeitong.smart.base.BaseActivity.onCreate(BaseActivity.java:61)
at android.app.Activity.performCreate(Activity.java:5135)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1146)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2315)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2403)
at android.app.ActivityThread.access$600(ActivityThread.java:165)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1373)
at android.os.Handler.dispatchMessage(Handler.java:107)
at android.os.Looper.loop(Looper.java:194)
at android.app.ActivityThread.main(ActivityThread.java:5400)
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:833)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
at dalvik.system.NativeStart.main(Native Method)