Groovy - 关闭vs方法 - 差异 [英] Groovy - closures vs methods - the difference

问题描述

如果你仔细查看包含的图片，您会注意到您可以使用Eclipse IDE重构Groovy代码，并将方法转换为闭包，反之亦然。那么，封闭又是什么？它与方法有什么不同？有人能给出一个使用闭包的好例子，以及为什么它是一个有用的功能？匿名内部类不够好？

解决方案

Closure是一个 Closure类实例调用逻辑。
它可以作为参数传递或分配给一个变量。它也有一些关于范围变量访问和委托调用的逻辑。

方法是普通的Java方法。没什么特别的。

是的，匿名内部类有很多样板代码来执行简单的操作。

比较：

  button.addActionListener（
 new ActionListener（）{
 public void actionPerformed（ActionEvent e）{
 frame.dispose（）; 
} 
} 
）; 
  

vs

  button.addActionListener {frame.dispose（）} 
  

在SO上有一个相关的问题 Groovy：闭包或方法
和3条包含大量用户指南的链接有用的信息。

1. http ：//groovy.codehaus.org/Closures


2. http://groovy.codehaus.org/Closures+-+Formal+Definition


3. http://groovy.codehaus.org/Closures+-+Informal+Guide

If you look very carefully at the picture included, you will notice that you can refactor Groovy code using the Eclipse IDE and convert a method to a closure and vice versa. So, what exactly is a closure again and how is it different than a method? Can someone give a good example of using a closure as well as why it's a useful feature? Anonymous inner classes weren't good enough?

解决方案

Closure is a Closure class instance, that implements Call logic. It may be passed as argument or assigned to a variable. It also has some logic concerned with scope variable accessing and delegating calls.

Methods are normal Java methods. Nothing special.

And yes, anonymous inner classes have a lot of boilerplate code to perform simple actions.

Compare:

button.addActionListener(
  new ActionListener() {
     public void actionPerformed( ActionEvent e ) {
          frame.dispose();
     }
  }
);

vs

button.addActionListener { frame.dispose() }

There is a related question on SO Groovy : Closures or Methods and 3 links to the user guide containing a lot of useful information.

1. http://groovy.codehaus.org/Closures
2. http://groovy.codehaus.org/Closures+-+Formal+Definition
3. http://groovy.codehaus.org/Closures+-+Informal+Guide

这篇关于Groovy - 关闭vs方法 - 差异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！