关于timer 空指针异常
海子尘 2010-02-04 05:28:52 import java.util.Timer;
import java.util.TimerTask;
public class Test {
public static void update(int id) {
Timer timer = new Timer();
timer.schedule(check(id), 1000);
}
static TimerTask check(int id) {
System.out.println(id);
return null;
}
public static void main(String[] args) {
Test.update(1);
}
}
打印:
1
Exception in thread "main" java.lang.NullPointerException
at java.util.Timer.sched(Unknown Source)
at java.util.Timer.schedule(Unknown Source)
at Test.update(Test.java:7)
at Test.main(Test.java:16)
是怎么回事?哪里来的异常啊!高手帮忙
还有就是如何关闭timer