線程-生產者與消費者問題（JAVA實現）

生產者與消費者問題（JAVA實現）

 public class TestProducerConsumer{
    public static void main(String[] agrs){
        SyncStack ss = new SyncStack();
        Producer p = new Producer(ss);
        ConSumer c = new ConSumer(ss);
        new Thread(p).start();
        new Thread(c).start();

    }
}

class Woto{

    int id;
    public Woto(int id){
        this.id = id;
    }

    public String toString(){
        return "Woto:" + id;
    }
}
class SyncStack{
    int index = 0;
    Woto[] w = new Woto[8];

    public synchronized void push(Woto wt){
        while(index == w.length){
            try {
                this.wait();
            } catch (InterruptedException e) {

                e.printStackTrace();
            }
        }
        this.notify();
        w[index] = wt;
        index++;
    }

    public synchronized Woto pop(){
        while(index == 0){
            try {
                this.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        this.notify();
        index--;
        return w[index];
    }
}

class Producer implements Runnable{
    SyncStack ss = null;
    public Producer(SyncStack ss){
        this.ss = ss;
    }

    public void run() {
        for(int i = 0;i<10;i++){
            Woto wt = new Woto(i);
            ss.push(wt);
            System.out.println("生產了="+wt);
            try {
                Thread.sleep((int) (Math.random() * 200));
            } catch (InterruptedException e) {

                e.printStackTrace();
            }
        }
    }
}

class ConSumer implements Runnable{
    SyncStack ss = null;
    public ConSumer(SyncStack ss){
        this.ss = ss;
    }

    public void run() {
        for(int i = 0;i<10;i++){

            Woto wt =ss.pop();
            System.out.println("消費了="+wt);
            try {
                Thread.sleep((int) (Math.random() * 1000));
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

        }
    }
}

為什麼會先出現消費者呢 ？求大神解答

這裡很明顯是先start生產者 怎麼可能先消費者呢
new Thread(p).start();
new Thread(c).start();

最佳回答：

線程是異步的，不是你先寫了誰誰就在前，看最好的效果就是弄2個線程通執行一個方法，，要想同步的只能是在同用一個方法時使用synchronized來修飾方法