自然排序

Person class—>实现Comparable，实现compareTo（）方法

package Homework1and2;

import java.text.CollationKey;
import java.text.Collator;

/**
 * Person类 有属性  name,age,sex 
   排序规则: 第一条件  年龄降序,第二条件  姓名 降序,第三条件 性别升序
 * @author Administrator
 *
 */
public class Person implements Comparable<Person> {
    private static String name;
    private int age;
    private String sex;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    @Override
    public String toString() {
        return "Person [name=" + name + ", age=" + age + ", sex=" + sex + "]";
    }
    public Person(String name, int age, String sex) {
        super();
        this.name = name;
        this.age = age;
        this.sex = sex;
    }
    public Person() {
        super();
    }
    //排序规则: 第一条件  年龄降序,第二条件  姓名 降序,第三条件 性别升序
    @Override
    public int compareTo(Person o) {
        if(age>o.age){
            return -1;
        }else if(age<o.age){
            return 1;
        }else {
            CollationKey key1=Collator.getInstance().getCollationKey(name);
            CollationKey key2=Collator.getInstance().getCollationKey(o.name);
            int num=key1.compareTo(key2);
            if(num>0){
                return -1;
            }else if(num<0){
                return 1;
            }else {
                CollationKey key3=Collator.getInstance().getCollationKey(sex);
                CollationKey key4=Collator.getInstance().getCollationKey(o.sex);
                int s=key3.compareTo(key4);
                if(s>0){
                    return 1;
                }else if(s<0){
                    return -1;
                }else {
                    return 0;
                }
            }

        }

    }

}

测试

public class Test1 {
    public static void main(String[] args){
        TreeSet<Person> list=new TreeSet<>();
        //年龄降序
        list.add(new Person("李白1", 15, "男"));
        list.add(new Person("李白2", 18, "男"));
        //姓名降序
        list.add(new Person("a妲己3", 20, "女"));
        list.add(new Person("z褒姒4", 20, "女"));
        //性别升序
        list.add(new Person("妲己", 17, "a女"));
        list.add(new Person("妲己", 17, "z男"));
        System.out.println(list);


    }
}