在同步块中调用 wait() 和 notify()方法，如果阻塞，通过循环来测试等待条件。请参考答案中的示例代码。
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import java.util.Vector; import java.util.logging.Level; import java.util.logging.Logger; public class Producer implements Runnable { private final Vector sharedQueue; private final int SIZE; public Producer(Vector sharedQueue, int size) { this.sharedQueue = sharedQueue; this.SIZE = size; } @Override public void run() { // 生产数据 for (int i = 0; i < 7; i++) { System.out.println("Produced:" + i); try { produce(i); } catch (InterruptedException ex) { Logger.getLogger(Producer.class.getName()).log(Level.SEVERE, null, ex); } } } private void produce(int i) throws InterruptedException { // wait if queue is full while (sharedQueue.size() == SIZE) { synchronized (sharedQueue) { System.out.println("Queue is full " + Thread.currentThread().getName() + " is waiting , size: " + sharedQueue.size()); sharedQueue.wait(); } } // producing element and notify consumers synchronized (sharedQueue) { sharedQueue.add(i); sharedQueue.notifyAll(); } } } |
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import java.util.Vector; import java.util.logging.Level; import java.util.logging.Logger; public class Consumer implements Runnable { private final Vector sharedQueue; private final int SIZE; public Consumer(Vector sharedQueue, int size) { this.sharedQueue = sharedQueue; this.SIZE = size; } @Override public void run() { // 消费数据 while (true) { try { System.out.println("Consumer: " + consume()); Thread.sleep(50); } catch (InterruptedException ex) { Logger.getLogger(Consumer.class.getName()).log(Level.SEVERE, null, ex); } } } private int consume() throws InterruptedException { // wait if queue is empty while (sharedQueue.isEmpty()) { synchronized (sharedQueue) { System.out.println("Queue is empty " + Thread.currentThread().getName() + " is waiting , size: " + sharedQueue.size()); sharedQueue.wait(); } } //otherwise consume element and notify waiting producer synchronized (sharedQueue) { sharedQueue.notifyAll(); return (Integer) sharedQueue.remove(0); } } } |
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import java.util.Vector; public class ProducerConsumerSolution { public static void main(String[] args) { Vector sharedQueue = new Vector(); int size = 4; Thread prodThread = new Thread(new Producer(sharedQueue, size), "Producer"); Thread consThread = new Thread(new Consumer(sharedQueue, size), "Consumer"); prodThread.start(); consThread.start(); } } |
运行结果：
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Produced:0 Queue is empty Consumer is waiting , size: 0 Produced:1 Consumer: 0 Produced:2 Produced:3 Produced:4 Produced:5 Queue is full Producer is waiting , size: 4 Consumer: 1 Produced:6 Queue is full Producer is waiting , size: 4 Consumer: 2 Consumer: 3 Consumer: 4 Consumer: 5 Consumer: 6 Queue is empty Consumer is waiting , size: 0 |
from:https://www.cnblogs.com/xbq8080/p/10371214.html