为什么我只能有一个 Calendar 对象实例 [英] Why can i have only one instance of Calendar object

问题描述

我只是想知道...

为什么我只能有一个 Calendar 对象的实例.有没有理由让它成为单身人士?

why can i have only one instance of Calendar object. Is there a reason for it to be a singleton?

我已尝试阅读 文档 但他们没有提到为什么需要这样做.快速谷歌搜索没有给我任何答案.

I have tried to read the documentation but they didn't mention why this is needed. And a quick google search didn't give me any answers.

推荐答案

Calendar 不是单例，它是一个抽象类.getInstance 方法是一个工厂方法，它返回 Calendar 类的具体实现.

Calendar is not a singleton, it is an abstract class. The getInstance method is a Factory method that returns a concrete implementation of the Calendar class.

在 Google 上搜索 java.util.Calendar 源代码，您将了解它是如何工作的.

Search Google for java.util.Calendar source code, and you will see how it works.

这篇关于为什么我只能有一个 Calendar 对象实例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！