如何在Java中使用Collections.sort()? [英] How to use Collections.sort() in Java?

问题描述

我有一个实现Comparable<Recipe>的对象Recipe:

public int compareTo(Recipe otherRecipe) {
    return this.inputRecipeName.compareTo(otherRecipe.inputRecipeName);
}

我这样做是为了能够按以下方法按字母顺序对List进行排序:

I've done that so I'm able to sort the List alphabetically in the following method:

public static Collection<Recipe> getRecipes(){
    List<Recipe> recipes = new ArrayList<Recipe>(RECIPE_MAP.values());
    Collections.sort(recipes);
    return recipes;
}

但是现在，以另一种方法命名为getRecipesSort()，我想对同一列表进行排序，但以数字方式比较包含其ID的变量.更糟的是，ID字段的类型为String.

But now, in a different method, lets call it getRecipesSort(), I want to sort the same list but numerically, comparing a variable that contains their ID. To make things worse, the ID field is of the type String.

如何使用Collections.sort()在Java中执行排序?

How do I use Collections.sort() to perform the sorts in Java?

推荐答案

使用此方法比较器并将其传递给

Use this method Collections.sort(List,Comparator) . Implement a Comparator and pass it to Collections.sort().

class RecipeCompare implements Comparator<Recipe> {

    @Override
    public int compare(Recipe o1, Recipe o2) {
        // write comparison logic here like below , it's just a sample
        return o1.getID().compareTo(o2.getID());
    }
}

然后将Comparator用作

Collections.sort(recipes,new RecipeCompare());

这篇关于如何在Java中使用Collections.sort()?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！