안녕하세요~

Caused by: java.lang.NoClassDefFoundError: org.springframework.http.HttpHeaders 에러가 발생했습니다.

04-24 10:22:33.682: ERROR/AndroidRuntime(7709): FATAL EXCEPTION: AsyncTask #1
04-24 10:22:33.682: ERROR/AndroidRuntime(7709): java.lang.RuntimeException: An error occured while executing doInBackground()
04-24 10:22:33.682: ERROR/AndroidRuntime(7709):     at android.os.AsyncTask$3.done(AsyncTask.java:200)
04-24 10:22:33.682: ERROR/AndroidRuntime(7709):     at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:274)
04-24 10:22:33.682: ERROR/AndroidRuntime(7709):     at java.util.concurrent.FutureTask.setException(FutureTask.java:125)
04-24 10:22:33.682: ERROR/AndroidRuntime(7709):     at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:308)
04-24 10:22:33.682: ERROR/AndroidRuntime(7709):     at java.util.concurrent.FutureTask.run(FutureTask.java:138)
04-24 10:22:33.682: ERROR/AndroidRuntime(7709):     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
04-24 10:22:33.682: ERROR/AndroidRuntime(7709):     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
04-24 10:22:33.682: ERROR/AndroidRuntime(7709):     at java.lang.Thread.run(Thread.java:1019)
04-24 10:22:33.682: ERROR/AndroidRuntime(7709): Caused by: java.lang.NoClassDefFoundError: org.springframework.http.HttpHeaders
04-24 10:22:33.682: ERROR/AndroidRuntime(7709):     at com.skplanet.sundew2.client.common.base.BaseNao.doInBackground(BaseNao.java:119)
04-24 10:22:33.682: ERROR/AndroidRuntime(7709):     at com.skplanet.sundew2.client.common.base.BaseNao.doInBackground(BaseNao.java:1)
04-24 10:22:33.682: ERROR/AndroidRuntime(7709):     at android.os.AsyncTask$2.call(AsyncTask.java:185)
04-24 10:22:33.682: ERROR/AndroidRuntime(7709):     at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306)
04-24 10:22:33.682: ERROR/AndroidRuntime(7709):     ... 4 more

해당 에러 로그이구요,

라이브러리는 추가된 상태인데 왜 이런 에러가 발생하는지 모르겠습니다.

Referenced Libraries 에 spring-android-rest-template-1.0.0.M4.jar 안에 org.springframework.http 안에 HttpHeaders.class 가 존재하는데 왜 에러가 발생하나요.. 어떤 경우에 발생하는지 힌트좀 주시면 감하사겠씁니당~