用 wait-notify 写一段代码来解决生产者-消费者问题？

package com.edu.chapter03.test;
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() {
// TODO Auto-generated method stub
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();
}
}
}

package com.edu.chapter03.test;
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() {
// TODO Auto-generated method stub
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);
}
}
}

package com.edu.chapter03.test;
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();
}
}