Java 多线程计算累加数

【题意】：开6条线程计算累加1 -> 10000000

【思路】：生产者-消费者 经典模型

1. 多个生产者负责生产(累加)做业
2. 生产者将生产结果存入共享仓库中
3. 消费者（主线程）从共享仓库中取出结果

/**
 * 多线程计算累加数
 */
public class Accumulate {
    public static void main(String[] args) {
        Storage storage = new Storage();
        // 为多个计算器对象建立线程
        Thread calThread1 = new Thread(new Calculate(1, storage), "Thread-1");
        Thread calThread2 = new Thread(new Calculate(2, storage), "Thread-2");
        Thread calThread3 = new Thread(new Calculate(3, storage), "Thread-3");
        Thread calThread4 = new Thread(new Calculate(4, storage), "Thread-4");
        Thread calThread5 = new Thread(new Calculate(5, storage), "Thread-5");
        Thread calThread6 = new Thread(new Calculate(6, storage), "Thread-6");

        calThread1.start();
        calThread2.start();
        calThread3.start();
        calThread4.start();
        calThread5.start();
        calThread6.start();

        // 打印最终结果
        storage.printTotal();
    }
}

/**
 * 计算器对象，负责计算start -> end
 */
class Calculate implements Runnable {
    private Storage storage;
    private long start;

    public Calculate(long start, Storage storage) {
        this.start = start;
        this.storage = storage;
    }

    @Override
    public void run() {
        long num = start;
        long sum = 0;
        while (num <= 10000000) {
            System.out.println(Thread.currentThread().getName() + " add num " + num);
            sum += num;
            num += 6;
        }
        // 线程计算完毕， 调用累加器进行累加
        storage.push(sum);
    }
}

/**
 * 仓库对象，负责累加
 */
class Storage {
    private long total = 0;
    private int count = 0;

    public synchronized void push(long sum) {
        total += sum;
        count++;
        notifyAll();
    }

    public synchronized void printTotal() {
        while (count < 6) {
            try {
                System.out.println(Thread.currentThread().getName() + " is wait");
                wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        System.out.println("storage result = " + total);
    }
}