ProduceConsumer.java

import java.util.Random;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

 /** com um array e wai e notify */
public class ProducerConsumer {

	static class Producer implements Runnable {
		
		private int[] items;

		public Producer(int[] items) {
			this.items = items;
		}

		@Override
		public void run() {
			Random rand = new Random();
			
			while(true) {
				synchronized (items) {
//					System.out.println("Fabricando");
					for(int i = 0; i < this.items.length; i++) {
						this.items[i] = rand.nextInt(100)+1;
					}
					items.notify();
				}
//				System.out.println("Terminou de fabricar");
			}
		}
	}
	
	static class Consumer implements Runnable {
		
		private int[] items;

		public Consumer(int[] items) {
			this.items = items;
		}

		@Override
		public void run() {
			synchronized (items) {
				try {
					while(true) {
						while(this.items[0] == 0) {
							this.items.wait();
						}
						
						System.out.println("Consumindo");
						for(int i = 0; i < this.items.length; i++) {
							System.out.println(this.items[i]);
							this.items[i] = 0;
						}
						System.out.println("Terminou");
					}
				} catch (InterruptedException e) {
					throw new RuntimeException(e);
				}
			}
		}
	}
	
	public static void main(String[] args) {
		int[] items = new int[20];
		Producer prod = new Producer(items);
		Consumer cons = new Consumer(items);
		
		ExecutorService executorService = Executors.newFixedThreadPool(2);
		
		executorService.execute(prod);
		executorService.execute(cons);
	}
}