java.lang.Object.wait() 导致当前线程等待，直到其他线程调用notify()方法或notifyAll()方法，此对象。换言之，此方法的行为就好像它简单地执行调用wait(0)。

当前线程必须拥有该对象的监视器。该监视器并等待另一个线程的线程释放所有权通知的线程在等待此对象的监视器上无论是通过调用notify方法或notifyAll方法唤醒。该线程要等到重新获得对监视器的所有权后才能继续执行。

这个方法只能由一个线程是此对象监视器的所有者被调用。看到其中一个线程能够成为监视器所有者的notify方法。

声明

以下是java.lang.Object.wait()方法的声明

public final void wait()

参数

• NA

返回值

这个方法没有返回值。

异常

• 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
         while (synchedList.isEmpty()) {
            System.out.println("List is empty...");
            synchedList.wait();
            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!