Java排序算法Collections.sort

Java排序算法Collections.sort

package com.example.core.mydemo.javaDemo;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

public class CustomSortExample {
    public static void main(String[] args) {
        List<String> list = new ArrayList<>();
        list.add("cherry");
        list.add("durian");
        list.add("apple");
        list.add("banana");
        list.add("a");
        System.out.println("排序前：" + list);
//        Collections.sort(list);
        //倒序
//        Collections.sort(list, Comparator.reverseOrder());
        //[a, apple, banana, cherry, durian]
//        Collections.sort(list, (s1, s2) -> s1.compareTo(s2));
        //[a, apple, banana, cherry, durian]
//        Collections.sort(list, Comparator.naturalOrder());
        //[banana, cherry, durian, a, apple]
//        Collections.sort(list, Comparator.comparingInt(String::hashCode));
        //[a, apple, banana, cherry, durian]
        Collections.sort(list, Comparator.comparing(s -> s));
        System.out.println("排序后：" + list);

        // 使用自定义Comparator进行排序
        Collections.sort(list, new LengthComparator());
        System.out.println("排序后2：" + list);
    }


}

class LengthComparator implements Comparator<String> {
    @Override
    public int compare(String s1, String s2) {
//        return s1.length() - s2.length();       //[a, apple, cherry, durian, banana]
//        return s1.charAt(0) - s2.charAt(0);  //[apple, a, banana, cherry, durian]
        return s1.hashCode() - s2.hashCode();  //[banana, cherry, durian, a, apple]
    }
}