使用Collections 将自定义对象进行排序

Posted 2020-11-25 when6

对象排序或比较的场合均需要Comparable接口

public class  User implements Comparable<User>{
    private String name;
    private int phone;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }    
    public int getPhone() {
        return phone;
    }
    public void setPhone(int phone) {
        this.phone = phone;
    }
    public String toString() {
        
        return name+"  "+phone;
    }
    User(String name ,int phone)
    {
        this.name=name;
        this.phone=phone;
    }
    public int compareTo(User anotherString) {
        int len1 = this.getName().length();
        int len2 = anotherString.getName().length();
        int lim = Math.min(len1, len2);
        char v1[] = this.getName().toCharArray();
        char v2[] = anotherString.getName().toCharArray();

        int k = 0;
        while (k < lim) {
            char c1 = v1[k];
            char c2 = v2[k];
            if (c1 != c2) {
                return c1 - c2;
            }
            k++;
        }
        return len1 - len2;
    }    
}

import java.util.*;
public class Test{
    public static void main(String[] args){
        List l =new ArrayList();
        l.add(new User("a",456123));
        l.add(new User("e",888123));
        l.add(new User("uuu",45993));
        l.add(new User("oo",33123));
        Collections.sort(l);
        System.out.println(l);
    }
}