Widget经常出错

03-24 23:28:33.049: V/is_rec=(1267): true
03-24 23:28:33.059: W/dalvikvm(1267): threadid=1: thread exiting with uncaught exception (group=0x4014a560)
03-24 23:28:33.059: E/AndroidRuntime(1267): FATAL EXCEPTION: main
03-24 23:28:33.059: E/AndroidRuntime(1267): java.lang.RuntimeException: Unable to start service com.hzhi.sms_widget.smsWidget$MyService@4064bf30 with Intent { act=btnDn_click flg=0x10000000 bnds=[375,314][455,359] }: java.lang.NullPointerException
03-24 23:28:33.059: E/AndroidRuntime(1267):  at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:2052)
03-24 23:28:33.059: E/AndroidRuntime(1267):  at android.app.ActivityThread.access$2800(ActivityThread.java:117)
03-24 23:28:33.059: E/AndroidRuntime(1267):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:994)
03-24 23:28:33.059: E/AndroidRuntime(1267):  at android.os.Handler.dispatchMessage(Handler.java:99)
03-24 23:28:33.059: E/AndroidRuntime(1267):  at android.os.Looper.loop(Looper.java:130)
03-24 23:28:33.059: E/AndroidRuntime(1267):  at android.app.ActivityThread.main(ActivityThread.java:3683)
03-24 23:28:33.059: E/AndroidRuntime(1267):  at java.lang.reflect.Method.invokeNative(Native Method)
03-24 23:28:33.059: E/AndroidRuntime(1267):  at java.lang.reflect.Method.invoke(Method.java:507)
03-24 23:28:33.059: E/AndroidRuntime(1267):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:875)
03-24 23:28:33.059: E/AndroidRuntime(1267):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:633)
03-24 23:28:33.059: E/AndroidRuntime(1267):  at dalvik.system.NativeStart.main(Native Method)
03-24 23:28:33.059: E/AndroidRuntime(1267): Caused by: java.lang.NullPointerException
03-24 23:28:33.059: E/AndroidRuntime(1267):  at com.hzhi.sms_widget.smsWidget.get_people_name(smsWidget.java:331)
03-24 23:28:33.059: E/AndroidRuntime(1267):  at com.hzhi.sms_widget.smsWidget$MyService.onStart(smsWidget.java:129)
03-24 23:28:33.059: E/AndroidRuntime(1267):  at android.app.Service.onStartCommand(Service.java:428)
03-24 23:28:33.059: E/AndroidRuntime(1267):  at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:2039)
03-24 23:28:33.059: E/AndroidRuntime(1267):  ... 10 more
129和331行出错，
129行是调用get_people_name(str_number);
331行在get_people_name()函数里面（红色的那一行）：
// 根据号码获得联系人姓名
public static void get_people_name(String x_number){

// 获得姓名
str_name = x_number;

String[] projection = {ContactsContract.PhoneLookup.DISPLAY_NAME,
ContactsContract.CommonDataKinds.Phone.NUMBER};
Cursor cursor = context.getContentResolver().query( 
                ContactsContract.CommonDataKinds.Phone.CONTENT_URI, 
                projection,     
                ContactsContract.CommonDataKinds.Phone.NUMBER + " = '" 
                + x_number + "'", 
                null,          
                null);

if (cursor != null){

for( int i = 0; i < cursor.getCount(); i++ ){
cursor.moveToPosition(i);
int nameFieldColumnIndex = 
cursor.getColumnIndex(ContactsContract.PhoneLookup.DISPLAY_NAME);
str_name = cursor.getString(nameFieldColumnIndex);
break;
}
cursor.close();
} }