java.lang.Object.wait(long timeout)方法实例
java.lang.Object.wait(long timeout) 导致当前线程等待,直到其他线程调用此对象的 notify() 方法或notifyAll()方法,或在指定已经过去的时间。
当前线程必须拥有该对象的监视器。
声明
以下是java.lang.Object.wait()方法的声明
public final void wait(long timeout)
参数
-
timeout -- 最大等待时间(毫秒)。
返回值
这个方法没有返回值。
异常
-
IllegalArgumentException --如果超时的值是负的。
-
IllegalMonitorStateException -- 如果当前线程不是对象监视器的拥有者。
-
InterruptedException -- 如果另一个线程中断了当前线程。当这种异常被抛出当前线程的中断状态被清除。
例子
下面的例子显示lang.Object.wait()方法的使用。
package com.yiibai; import java.util.Collections; import java.util.LinkedList; import java.util.List; public class ObjectDemo extends Object { private List synchedList; public ObjectDemo() { // create a new synchronized list to be used synchedList = Collections.synchronizedList(new LinkedList()); } // method used to remove an element from the list public String removeElement() throws InterruptedException { synchronized (synchedList) { // while the list is empty, wait up to 10 seconds while (synchedList.isEmpty()) { System.out.println("List is empty..."); synchedList.wait(10000); System.out.println("Waiting..."); } String element = (String) synchedList.remove(0); return element; } } // method to add an element in the list public void addElement(String element) { System.out.println("Opening..."); synchronized (synchedList) { // add an element and notify all that an element exists synchedList.add(element); System.out.println("New Element:'" + element + "'"); synchedList.notifyAll(); System.out.println("notifyAll called!"); } System.out.println("Closing..."); } public static void main(String[] args) { final ObjectDemo demo = new ObjectDemo(); Runnable runA = new Runnable() { public void run() { try { String item = demo.removeElement(); System.out.println("" + item); } catch (InterruptedException ix) { System.out.println("Interrupted Exception!"); } catch (Exception x) { System.out.println("Exception thrown."); } } }; Runnable runB = new Runnable() { // run adds an element in the list and starts the loop public void run() { demo.addElement("Hello!"); } }; try { Thread threadA1 = new Thread(runA, "A"); threadA1.start(); Thread.sleep(500); Thread threadA2 = new Thread(runA, "B"); threadA2.start(); Thread.sleep(500); Thread threadB = new Thread(runB, "C"); threadB.start(); Thread.sleep(1000); threadA1.interrupt(); threadA2.interrupt(); } catch (InterruptedException x) { } } }
让我们来编译和运行上面的程序,这将产生以下结果:
List is empty... List is empty... Opening... New Element:'Hello!' notifyAll called! Closing... Waiting... Hello! Waiting... List is empty... Interrupted Exception!