Runtime.getRuntime().addShutdownHook介绍

介绍

从函数的字面意思上我们很很好理解就是JVM在关闭的时候会逐渐关闭钩子里面添加的函数，见详细例子：‘

例子

public class Test {
	static class ThreadOne extends Thread {
		public void run() {
			int i = 0;
			while (i < 3) {
				try {
					Thread.sleep(2000);
				} catch (InterruptedException ex) {
				}
				System.out.println("=====Thread 1=====");
				i++;
			}
		}
	}

	static class ThreadTwo extends Thread {
		public void run() {
			int i = 0;
			while (i < 3) {
				try {
					Thread.sleep(1000);
				} catch (InterruptedException ex) {
				}
				System.out.println("======Thread 2=====");
				i++;
			}
		}
	}

	static class ThreadThree extends Thread {
		public void run() {
			System.out.println("#####Thread 3#####");
		}
	}

	public static void main(String[] args) {
		Runtime.getRuntime().addShutdownHook(new ThreadThree());
		ThreadOne t1 = new ThreadOne();
		t1.start();
		ThreadTwo t2 = new ThreadTwo();
		t2.start();
	}
}

结果

======Thread 2=====
======Thread 2=====
=====Thread 1=====
======Thread 2=====
=====Thread 1=====
=====Thread 1=====
#####Thread 3#####