事件侦听器与Java中的处理程序 [英] What's the difference between Event Listeners & Handlers in Java?

问题描述

一般来说，java中有听众和处理程序的事件。

我的意思是我不知不觉中使用它们，只要API中可用。我的问题是，在什么情况下我们使用监听器，在什么情况下我们使用处理程序进行事件？

他们有什么区别？特征??

我搜索了原因，找不到适合Java的解释。

解决方案

听众和处理程序之间没有正式的区别。有些人可能会认为它们是可以互换的。然而对我来说，它们的意思略有不同。

听众是一个从源中订阅事件的对象。参看观察者模式。通常，您可以让许多听众订阅每种类型的事件，并通过 添加 XyzListener 方法添加 / p>

示例： MouseListener 。

处理程序是负责处理某些事件的对象。典型的情况是为特定事件/任务提供一个处理程序作为构造函数的参数，或者通过 set XyzHandler 设置处理程序方法。换句话说，您通常对每种类型的事件都有一个处理程序。

示例： MemoryHandler 在Java API中。

In general terms of java, there are listeners & handlers for events.
I mean I use them unknowingly, just whichever is available in the API.

My question is, in what case do we use listeners and in what case do we use handlers for events?

What's the difference between them? Characteristics??

I've searched for reasons and I couldn't find a proper explanation for Java.

解决方案

There's no formally defined difference between listeners and handlers. Some people probably would probably argue that they are interchangeable. To me however, they have slightly different meaning.

A listener is an object that subscribes for events from a source. Cf. the observer pattern. Usually you can have many listeners subscribing for each type of event, and they are added through addXyzListener methods.

Example: The MouseListener in the Java API.

A handler is an object that is responsible for handling certain events. A typical scenario would be to provide a handler for a specific event/task as an argument to a constructor, or set the handler through a setXyzHandler method. In other words, you usually have one handler for each type of event.

Example: The MemoryHandler in the Java API.

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