java.lang.Object.wait(long timeout, int nanos)方法實例
java.lang.Object.wait(long timeout, int nanos) 導致當前線程等待,直到其他線程調用此對象的 notify() 方法或notifyAll()方法,或在指定已經過去的時間。
此方法類似於wait方法的一個參數,但它允許更好地控製的時間等待一個通知放棄之前的量。實時量,以毫微秒計算,計算公式如下:
1000000*timeout+nanos
在所有其他方麵,這種方法與wait(long)做同樣的事情。特彆是wait(0, 0) 表示和wait(0)相同。
當前線程必須擁有該對象的監視器。
聲明
以下是java.lang.Object.wait()方法的聲明
public final void wait(long timeout, int nanos)
參數
-
timeout -- 最大等待時間(毫秒)。
-
nanos -- 附加時間在毫微秒範圍0-999999。
返回值
這個方法冇有返回值。
異常
-
IllegalArgumentException -- 如果超時的值是負的或毫微秒的值不在0-999999範圍內。
-
IllegalMonitorStateException -- 如果當前線程不是對象監視器的擁有者。
-
InterruptedException -- 如果另一個線程中斷了當前線程。當這種異常被拋出當前線程的中斷狀態被清除。
例子
下麵的例子顯示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 and 500 nanos while (synchedList.isEmpty()) { System.out.println("List is empty..."); synchedList.wait(10000, 500); 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) { } } }
讓我們來編譯和運行上麵的程序,這將產生以下結果:
List is empty... List is empty... Opening... New Element:'Hello!' notifyAll called! Closing... Waiting... Hello! Waiting... List is empty... Interrupted Exception!