下面的代码,为什么我一调用stop()方法就会报空指针的异常?
public class SingleUtil {
private Context con;
private HandlerThread handlerThread;
private Handler handler;
private static final int THREAD_NUMBER_ONE = 1;
int num = 0;
public SingleUtil() {
}
public SingleUtil(Context con) {
this.con = con;
}
public void SingleLoop(final String a) {
handlerThread = new HandlerThread("name");
handlerThread.start();
handler = new Handler(handlerThread.getLooper()) {
@Override
public void handleMessage(Message msg) {
num = num++;
String str = null;
try {
//访问网络耗时操作
str = PhoneUtil.information(a);
UpLoading ul = new UpLoading(con);
ul.sign(str);
} catch (Exception e) {
e.printStackTrace();
}
handler.sendEmptyMessageDelayed(THREAD_NUMBER_ONE, 5*1000);//消息循环
}
};
handler.sendEmptyMessage(THREAD_NUMBER_ONE);//启动消息
}
public void stop(){
Message msg = handler.obtainMessage();
handler.removeMessages(THREAD_NUMBER_ONE);
}
}