实例如何与其实例化器通信？ [英] How can an instance communicate with its instantiator?

问题描述

给出一个非常简单的例子：

Given a really oversimplified example:

Class A {
    B b = new B();
}

Class B {
    //unicorns and what-not
    //Something happens and I want to let A know
    //Yet I don't want to return and exit
}   

B可以通过任何方式进行交流吗？有一个没有插座的？
通过交流，我的意思是B将值发送给A而没有A在B上调用方法。

Is there any way that B can communicate with A without Sockets? By communicate, I mean B sending values to A without A invoking a method on B.

编辑：谢谢您的支持回应。以下是我的后续问题：

EDIT: Thank you for your responses. This following is my follow up question:

如果我有以下内容，并且2个B实例同时调用了signal（）方法，这将导致每个B两次调用动作。我该怎么办？

If I had the following, and method signal() is called simultaneously by 2 instances of B, this will cause a conflict of every B calling action twice. What can I do to solve it?

//Modified from Jon Skeet
public class A {
    private B b[];

    public A() {
        //for loop
        b[i] = new B(this);
    }

    public void signal() {
        //for loop
        b[i].action();
    }
}

public class B {
    A creator;

    public B(A creator) {
        this.creator = creator;
    }

    public void action() {
        //stuff
    }

    public void main(String[] args) {

        while(true)
            if(something==true) {
                creator.signal();
            }

   }
}

推荐答案

让他们两个都访问同一个 Queue 。一个放置元素，另一个放置元素。如果它们在不同的线程中，则 BlockingQueue 实现应该可以解决问题。

Give them both access to the same Queue. One puts elements onto it, the other pulls elements from it. If they're in separate threads, one of the BlockingQueue implementations should do the trick.

这篇关于实例如何与其实例化器通信？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！