안녕하세요

안드로이드를 공부하고 있는 학생입니다.

지금 MediaPlayer 쪽을 공부해 볼려고 하는데 어학용으로 구간을 나눠서 구간 반복을 만들어 볼려고 합니당

어느정도 구간을 나눠서 반복까진 됐는데 그부분을 종료 시킬려고만 하면 에러가 뜨네요 ㅠㅠ

도움 부탁 드립니다. ㅠ

소스코드입니다. 부탁드려요 ㅠㅠ
시작 버튼과 종료 버튼이 있고, 사운드를 올리고 내리는 버튼 까진 쉽게 됐습니다.
Flag 를 처음 누르면 시작 지점을 가져오고, 두번째 누르게 되면 끝 부분을 가져와서 반복이 시작되는구도 입니당.
3번재 눌렀을때 구간 반복을 종료 시키고 싶은데 ㅠㅠ 구간 반복은 되는데 3번째 눌렀을때 에러가 뜨네요 ㅠ.ㅠ

에러 코드 입니다 ㅠ
04-13 06:30:48.524: ERROR/AndroidRuntime(3686): Uncaught handler: thread main exiting due to uncaught exception
04-13 06:30:48.595: ERROR/AndroidRuntime(3686): java.lang.NullPointerException
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at java.lang.Thread.stop(Thread.java:1374)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at my.Media.Media$5.onClick(Media.java:81)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at android.view.View.performClick(View.java:2364)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at android.view.View.onTouchEvent(View.java:4179)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at android.widget.TextView.onTouchEvent(TextView.java:6540)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at android.view.View.dispatchTouchEvent(View.java:3709)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1659)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1107)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at android.app.Activity.dispatchTouchEvent(Activity.java:2061)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1643)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at android.view.ViewRoot.handleMessage(ViewRoot.java:1691)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at android.os.Handler.dispatchMessage(Handler.java:99)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at android.os.Looper.loop(Looper.java:123)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at android.app.ActivityThread.main(ActivityThread.java:4363)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at java.lang.reflect.Method.invokeNative(Native Method)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at java.lang.reflect.Method.invoke(Method.java:521)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
04-13 06:30:48.595: ERROR/AndroidRuntime(3686):     at dalvik.system.NativeStart.main(Native Method)
04-13 06:30:48.675: INFO/Process(57): Sending signal. PID: 3686 SIG: 3
04-13 06:30:48.684: INFO/dalvikvm(3686): threadid=7: reacting to signal 3
04-13 06:30:48.766: INFO/dalvikvm(3686): Wrote stack trace to '/data/anr/traces.txt'
04-13 06:30:49.115: WARN/MediaPlayer(3686): info/warning (1, 44)
04-13 06:30:49.455: DEBUG/AudioSink(30): bufferCount (4) is too small and increased to 12
04-13 06:30:49.575: WARN/MediaPlayer(3686): info/warning (1, 44)
04-13 06:30:51.555: INFO/Process(3686): Sending signal. PID: 3686 SIG: 9
04-13 06:30:51.657: INFO/ActivityManager(57): Process my.Media (pid 3686) has died.
04-13 06:30:51.706: INFO/WindowManager(57): WIN DEATH: Window{43cf4010 my.Media/my.Media.Media paused=false}
04-13 06:30:51.836: WARN/WindowManager(57): No window to dispatch pointer action 0
04-13 06:30:51.945: WARN/WindowManager(57): No window to dispatch pointer action 1
04-13 06:30:51.975: ERROR/gralloc(57): [unregister] handle 0x436bd0 still locked (state=40000001)

ㅠ ㅠ 도움부탁드립니다. 며칠째 이것 때문에 머리가 너무 아프네요 ㅠ ㅠ