使用 Collections 实现排序 sort方法对List 实体类实现Comparable类示例

淩亂°似流年 2023-08-17 16:53 45阅读 0赞

package com.test.jj;
    
    
    import java.util.ArrayList;
    import java.util.Collections;
    
    public class Test {
        ArrayList<Test.Men> mens = new ArrayList<Test.Men>();
    
        public Test() {
            int[] ages = new int[] { 13, 54, 23, 45, 76, 22, 18, 69 };
            for (int i = 0; i < ages.length; i++) {
                mens.add(new Men(ages[i]));
            }
            Collections.sort(this.mens);
        }
    
        public ArrayList<Test.Men> getMens() {
            return mens;
        }
    
        public static void main(String[] args) {
            Test test = new Test();
            for (Test.Men men : test.getMens()) {
                System.out.println(men.getAge());
            }
        }
        
        
    
        public class Men implements Comparable<Men> {
            private int age;
    
            public Men(int age) {
                super();
                this.age = age;
            }
    
            public int getAge() {
                return age;
            }
    
            public int compareTo(Men o) {
                if (age > o.getAge()) {
                    return 1;
                } else if (age == o.getAge()) {
                    return 0;
                } else {
                    return -1;
                }
            }
    
        }
    }

从大到小输出

public int compareTo(Men o) {
                if (age > o.getAge()) {
                    return 1;
                } else if (age == o.getAge()) {
                    return 0;
                } else {
                    return -1;
                }
            }

从小到大输出

转载于:https://www.cnblogs.com/zimublog/p/8581593.html