Causes the current thread to wait until another thread invokes the notify() method or the notifyAll() method for this object. In other words, this method behaves exactly as if it simply performs the call wait(0). The current thread must own this object‘s monitor. The thread releases ownership of this monitor and waits until another thread notifies threads waiting on this object‘s monitor to wake up either through a call to the notify method or the notifyAll method. The thread then waits until it can re-obtain ownership of the monitor and resumes execution. As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop: synchronized (obj) { while (<condition does not hold>) obj.wait(); ... // Perform action appropriate to condition } This method should only be called by a thread that is the owner of this object‘s monitor. See the notify method for a description of the ways in which a thread can become the owner of a monitor.
/** * @throws IllegalMonitorStateException if the current thread is not * the owner of this object‘s monitor. * @see java.lang.Object#notifyAll() * @see java.lang.Object#wait() */ public final native void notify();
* @throws IllegalMonitorStateException if the current thread is not * the owner of this object‘s monitor. * @see java.lang.Object#notify() * @see java.lang.Object#wait() */ public final native void notifyAll();
1 public class TestSetAndGet { 2 static class Goods { 3 public String lock = Thread.currentThread().getName()+"test"; 4 volatile static int number = 1; 5 private static final int max_size = 10; 6 7 // 生产者增加一个产品 8 public void set() throws InterruptedException { 9 synchronized (this) { 10 while (number >= max_size) { 11 // wait()方法一定要持有锁对象的minitor监视器，所以一定要放在notify之前 12 wait(); 13 } 14 if (number == 0) { 15 System.out.print("-同时唤醒所有的消费者和生产者。"); 16 notifyAll(); 17 } 18 number++; 19 System.out.print("生产者增加一个，当前数量："+number); 20 System.out.println(); 21 } 22 } 23 // 消费者消费一个产品 24 public void get() throws InterruptedException { 25 synchronized (this) { 26 while (number <= 0) { 27 // wait()方法一定要持有锁对象的minitor监视器，所以一定要放在notify之前 28 wait(); 29 } 30 if (number == max_size) { 31 System.out.print("唤醒所有的消费者和生产者。"); 32 notifyAll(); 33 } 34 number--; 35 System.out.print("消费者消费一个，当前数量："+number); 36 System.out.println(); 37 } 38 } 39 } 40 41 public static void main(String[] args) throws InterruptedException { 42 Goods goods = new Goods(); 43 44 for (int i = 0; i < 20; i++) { 45 // 生产者慢一点,可以让货物在0-1之间盘桓 46 //Thread.sleep(100); 47 new Thread(()->{ 48 try { 49 goods.set(); 50 } catch (InterruptedException e) { 51 e.printStackTrace(); 52 } 53 }).start(); 54 } 55 for (int i = 0; i < 20; i++) { 56 new Thread(()->{ 57 try { 58 goods.get(); 59 } catch (InterruptedException e) { 60 e.printStackTrace(); 61 } 62 }).start(); 63 } 64 65 } 66 }
多线程-4wait() notify() notifyAll() 生产者消费者模型
原文：https://www.cnblogs.com/ningbing/p/14524012.html