Android App Problem

Android Native Call Example giving NullpointerException how can I handle this?

Logs :

06-30 12:20:24.151 342-342/com.ericsson.research.owr.examples.nativecall D/NativeCall﹕ onJoinClicked
06-30 12:20:24.206 342-342/com.ericsson.research.owr.examples.nativecall W/libOpenSLES﹕ Leaving Object::GetInterface (SL_RESULT_FEATURE_UNSUPPORTED)
06-30 12:20:24.216 342-342/com.ericsson.research.owr.examples.nativecall D/NativeCall﹕ setting self-view: android.view.TextureView{42a7dc58 V.ED..C. ......ID 662,542-1046,830 #7f060008 app:id/self_view}
06-30 12:20:24.706 342-517/com.ericsson.research.owr.examples.nativecall I/System.out﹕ Thread-13890 calls detatch()
06-30 12:20:24.706 342-342/com.ericsson.research.owr.examples.nativecall W/EventSource﹕ unhandled event: busy
06-30 12:20:24.721 342-342/com.ericsson.research.owr.examples.nativecall D/NativeCall﹕ stopping self-view
06-30 12:20:24.721 342-342/com.ericsson.research.owr.examples.nativecall D/AndroidRuntime﹕ Shutting down VM
06-30 12:20:24.721 342-342/com.ericsson.research.owr.examples.nativecall W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0x41868c08)
06-30 12:20:24.721 342-342/com.ericsson.research.owr.examples.nativecall E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.ericsson.research.owr.examples.nativecall, PID: 342
java.lang.NullPointerException
at com.ericsson.research.owr.examples.nativecall.NativeCallExampleActivity.onDisconnect(NativeCallExampleActivity.java:338)
at com.ericsson.research.owr.examples.nativecall.SignalingChannel$1$1.run(SignalingChannel.java:120)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:157)
at android.app.ActivityThread.main(ActivityThread.java:5356)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1265)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1081)
at dalvik.system.NativeStart.main(Native Method)
06-30 12:20:24.881 342-359/com.ericsson.research.owr.examples.nativecall D/Camera﹕ app passed NULL surface
06-30 12:20:25.386 342-359/com.ericsson.research.owr.examples.nativecall D/Camera﹕ app passed NULL surface
06-30 12:20:25.501 342-359/com.ericsson.research.owr.examples.nativecall I/g_log﹕ _owr_media_source_release_source: assertion 'GST_IS_ELEMENT(source)' failed
06-30 12:20:25.871 342-359/com.ericsson.research.owr.examples.nativecall I/gst_log﹕ 0x78399f80 ERROR default jni/android_video_capture_device.c:2504:VCD_unprepare: jni/android_video_capture_device.c VCD_unprepare ERROR: illegal state (4)
06-30 12:20:25.871 342-359/com.ericsson.research.owr.examples.nativecall E/gstandroidvideosrc﹕ jni/android_video_capture_device.c VCD_unprepare ERROR: illegal state (4)
06-30 12:20:25.871 342-359/com.ericsson.research.owr.examples.nativecall I/gst_log﹕ 0x78399f80 ERROR gstandroidvideosrc jni/gst_android_video_source.c:248:gst_android_video_source_change_state: gst_android_video_source_change_state: ERROR: Could not change state
06-30 12:20:25.871 342-359/com.ericsson.research.owr.examples.nativecall E/gstandroidvideosrc﹕ gst_android_video_source_change_state: ERROR: Could not change state
06-30 12:20:25.871 342-359/com.ericsson.research.owr.examples.nativecall I/gst_log﹕ 0x78399f80 ERROR default jni/android_video_capture_device.c:2504:VCD_unprepare: jni/android_video_capture_device.c VCD_unprepare ERROR: illegal state (4)
06-30 12:20:25.871 342-359/com.ericsson.research.owr.examples.nativecall E/gstandroidvideosrc﹕ jni/android_video_capture_device.c VCD_unprepare ERROR: illegal state (4)
06-30 12:20:25.871 342-359/com.ericsson.research.owr.examples.nativecall I/gst_log﹕ 0x78399f80 ERROR gstandroidvideosrc jni/gst_android_video_source.c:248:gst_android_video_source_change_state: gst_android_video_source_change_state: ERROR: Could not change state
06-30 12:20:25.871 342-359/com.ericsson.research.owr.examples.nativecall E/gstandroidvideosrc﹕ gst_android_video_source_change_state: ERROR: Could not change state
06-30 12:20:26.366 342-671/com.ericsson.research.owr.examples.nativecall D/dalvikvm﹕ threadid=12: thread exiting, not yet detached (count=0)

Start by reading NativeCallExampleActivity.java at onDisconnect, line 338, then follow the callback from SignalingChannel.java line 120. Reproduce the Android Native Call example using the supplied log sequence and inspect the null value reached during disconnect. Done means the reported NullPointerException no longer occurs during disconnect.

Written by the indexing model from the issue text.