java - wait() 和 notification() 相关问题

Question

我只是想使用线程打印从1到10。但是我的代码将在数字1处停止。input()将提供从1到10的变量，而output()将打印出它们。首先执行input()，然后执行output()。之后 for() 将确保它们将开始另一个迭代。

class InputOutput{
    private static int i=0;
    private static boolean ToF=false;

    synchronized void output(){
        try{
            while(!ToF){
                notify();
                wait();
            }
        }
            catch(InterruptedException e){
                e.printStackTrace();
            }
        System.out.println("Output: "+i);
        ToF=false;
        notify();
    }
    synchronized void input(){
        try{
            while(ToF){
                notify();
                wait();
            }
        }
            catch(InterruptedException e){
                e.printStackTrace();
            }
        i++;
        ToF=true;
        notify();
    }
    class input implements Runnable{
    private int i=1;
    InputOutput io=new InputOutput();
    public void run(){
        for(i=1;i<=10;i++)
            io.input();
    }
    }
    class output implements Runnable{
    private int i=1;
    InputOutput io=new InputOutput();
    public void run(){
        for(i=1;i<=10;i++)
            io.output();
    }
    }
    public class Homework07Part3 {

    public static void main(String[] args) {
        Thread t1=new Thread(new input());
        t1.start();
        Thread t2=new Thread(new output());
        t2.start();
    }
}

Answer 1

while 循环将等待两个线程通信的单个对象

while(ToF){
           //dont put notify here.
            notify();
            wait();
        }

使其成为实例变量

private static boolean ToF=false;

公共(public)课Homework07Part3{

    public static void main(String[] args) {
        InputOutput io = new InputOutput();
        Thread t1 = new Thread(new input(io));
        t1.start();
        Thread t2 = new Thread(new output(io));
        t2.start();
    }

    private static class input implements Runnable {
        private int i = 1;
        private InputOutput io;

        public input(InputOutput io) {
            this.io = io;
        }

        public void run() {
            for (i = 1; i <= 10; i++)
                io.input();
        }
    }

    private static class output implements Runnable {
        private int i = 1;
        private InputOutput io;

        public output(InputOutput io) {
            this.io = io;
        }

        public void run() {
            for (i = 1; i <= 10; i++)
                io.output();
        }
    }
}

class InputOutput {
    private int i = 0;
    private boolean ToF = false;

    synchronized void output() {
        try {
            while (!ToF) {
                wait();
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("Output: " + i);
        ToF = false;
        notify();
    }

    synchronized void input() {
        try {
            while (ToF) {
                wait();
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        i++;
        ToF = true;
        notify();
    }

}