生产者消费者问题（第一版简易版本）

创建生产和消费的对象类

public class Book {
    private String name;	// 书本名称
    private int num = 0;	//当前书本的本数

    public Book() {
    }

    public Book(String name, int num) {
        this.name = name;
        this.num = num;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getNum() {
        return num;
    }

    public void setNum(int num) {
        this.num = num;
    }
}

生产者类

生产者类实现Runnable接口

public class Producer implements Runnable {
    private int count;
    Book book;

    public Producer(Book book) {
        this.book = book;
    }

    @Override
    public void run() {
        while (true) {
            synchronized (book) {
                if (book.getNum() > 0) {
                    try {
                        book.wait();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                } else {
                    count++;
                    book.setNum(count);
                    System.out.println("生产者" + Thread.currentThread().getName() + "生产" + book.getName() + "本数" + book.getNum());
                    book.notify();
                    count = 0;
                }

            }
        }
    }
}

锁对象为当前生产的书对象，当书的数量大于0的时候等待消费者消费书本；当书本数量小于等于0本时生产者生产书本并通知消费者消费。

消费者类

public class Consumer implements Runnable {
    Book book;

    public Consumer() {
    }

    public Consumer(Book book) {
        this.book = book;
    }

    @Override
    public void run() {
        while (true) {
            synchronized (book) {
                if (book.getNum() == 0) {
                    try {
                        book.wait();    // 等待生产者生产资源
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                } else {
                    System.out.println("消费者：" + Thread.currentThread().getName() + "消费" + book.getName() + "本数：" + book.getNum());
                    book.setNum(0);     // 消费完资源
                    book.notify();      // 通知生产者生产资源
                }
            }
        }
    }
}

消费者对象判断生产者对象是否生产了书，若生产了书，则消耗书本；反之通知生产者生产并等待生产者生产。

运行类和运行截图

public class ConsumerAndProducerTest {
    public static void main(String[] args) {

        Book book = new Book("1", 0);
        Producer producer = new Producer(book);
        Consumer consumer = new Consumer(book);

        Thread t1 = new Thread(producer);
        Thread t2 = new Thread(consumer);
        t1.start();
        t2.start();
    }
}