HashMap问题

Type safety: The expression of type HashMap needs unchecked conversion to conform to HashMap<String,String> Student.java /Text_2Activity_2Service/src/com/pan/xiaoa line 36 Java Problem
这个语句： p.scores  = source.readHashMap(HashMap.class.getClassLoader());会有上边的警告，怎么解决啊？
每次编译时都会产生下边一大堆的错误：

03-24 00:55:30.738: W/dalvikvm(277): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
03-24 00:55:30.767: E/AndroidRuntime(277): FATAL EXCEPTION: main
03-24 00:55:30.767: E/AndroidRuntime(277): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.pan.xiaoa/com.pan.xiaoa.ActivityOne}: java.lang.NullPointerException: println needs a message
03-24 00:55:30.767: E/AndroidRuntime(277):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
03-24 00:55:30.767: E/AndroidRuntime(277):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
03-24 00:55:30.767: E/AndroidRuntime(277):  at android.app.ActivityThread.access$2300(ActivityThread.java:125)
03-24 00:55:30.767: E/AndroidRuntime(277):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
03-24 00:55:30.767: E/AndroidRuntime(277):  at android.os.Handler.dispatchMessage(Handler.java:99)
03-24 00:55:30.767: E/AndroidRuntime(277):  at android.os.Looper.loop(Looper.java:123)
03-24 00:55:30.767: E/AndroidRuntime(277):  at android.app.ActivityThread.main(ActivityThread.java:4627)
03-24 00:55:30.767: E/AndroidRuntime(277):  at java.lang.reflect.Method.invokeNative(Native Method)
03-24 00:55:30.767: E/AndroidRuntime(277):  at java.lang.reflect.Method.invoke(Method.java:521)
03-24 00:55:30.767: E/AndroidRuntime(277):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
03-24 00:55:30.767: E/AndroidRuntime(277):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
03-24 00:55:30.767: E/AndroidRuntime(277):  at dalvik.system.NativeStart.main(Native Method)
03-24 00:55:30.767: E/AndroidRuntime(277): Caused by: java.lang.NullPointerException: println needs a message
03-24 00:55:30.767: E/AndroidRuntime(277):  at android.util.Log.println_native(Native Method)
03-24 00:55:30.767: E/AndroidRuntime(277):  at android.util.Log.d(Log.java:122)
03-24 00:55:30.767: E/AndroidRuntime(277):  at com.pan.xiaoa.ActivityOne.processExtraData(ActivityOne.java:34)
03-24 00:55:30.767: E/AndroidRuntime(277):  at com.pan.xiaoa.ActivityOne.onCreate(ActivityOne.java:27)
03-24 00:55:30.767: E/AndroidRuntime(277):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
03-24 00:55:30.767: E/AndroidRuntime(277):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
03-24 00:55:30.767: E/AndroidRuntime(277):  ... 11 more



Android HashMap

补充：移动开发 ,  Android