ID生成器创建的对象 [英] ID generator for the Objects created

问题描述

我需要一个类，它创建对象为每个创建的对象分配一个ID。此ID通常是类的int属性。我想要这个值（ID）增加每次一个对象被创建，然后被分配给该对象从1开始。它激励我，我需要一个静态int属性。

I need a class which creates Objects assigning an ID to each Object created. This ID is as usual an int attribute to the class. I want this value (ID) to be increased each time an Object is created and then to be assigned to that Object starting with 1. It strikes me that I need a static int attribute.

如何初始化此静态属性？

How can I initialize this static attribute?

我应该创建一个单独的方法来做ID的增量（作为ID生成器），在构造函数中调用它吗？

Should I create a separate method to do the increment of the ID (as an ID generator) which is invoked inside the constructor?

一般来说，最有效和精心设计的方式是什么？

What is in general the most effective and well-designed manner to implement that?

推荐答案

就像你提到使用 static int 在创建新对象时增加它。

Just like you mention use a static int for the id, and increment it when creating new objects.

class MyObject {

    private static int counter = 0;

    public final int objectId;

    MyObject() {
        this.objectId = counter++;
    }
}

请注意，您需要保护 counter ++ 如果 MyObject 是由多个线程创建的（例如使用 AtomicInteger 其他答案建议）。

Please note that you need to protect counter++ if MyObject is created by multiple threads (for example using AtomicInteger as the other answers suggest).

这篇关于ID生成器创建的对象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！