如何仅在一个班级中制作 2 个可比较的方法? [英] How do I make 2 comparable methods in only one class?

问题描述

我有一个类，我已经按一个属性对其进行了排序.现在我需要做另一件事，我需要创建另一种方式来对我的数据进行排序.我怎样才能做到，所以我可以在两种方法之间进行选择.我知道的唯一命令是 Collections.sort，它将从我想要比较其数据的类中选取方法 compareTo.

I've got one class, that I sort it already by one attribute. Now I need to make another thing, that I need to create another way to sort my data. How can I make it, so I can choose between the two methods. The only command I know is Collections.sort that will pick up the method compareTo from the class I want to compare its data.

有可能吗?

推荐答案

你需要做的是实现一个自定义的Comparator.然后使用:

What you need to do is implement a custom Comparator. And then use:

Collections.sort(yourList, new CustomComparator<YourClass>());

具体来说，您可以编写:(这将创建一个实现 Comparator 的匿名类.)

Specifically, you could write: (This will create an Anonymous class that implements Comparator.)

Collections.sort(yourList, new Comparator<YourClass>(){
    public int compare(YourClass one, YourClass two) {
        // compare using whichever properties of ListType you need
    }
});

如果您愿意，您可以将这些构建到您的类中:

You could build these into your class if you like:

class YourClass {

    static Comparator<YourClass> getAttribute1Comparator() {
        return new Comparator<YourClass>() {
            // compare using attribute 1
        };
    }

    static Comparator<YourClass> getAttribute2Comparator() {
        return new Comparator<YourClass>() {
            // compare using attribute 2
        };
    }
}

可以这样使用:

Collections.sort(yourList, YourClass.getAttribute2Comparator());

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