十四、new Comparator<T>实现多重排序结果

1、编写实现类

package com.abcd;

public class Person{

    private String name;
    private int age;
    private int salary;

    public Person() {
    }

    public Person(String name, int age, int salary) {
        this.name = name;
        this.age = age;
        this.salary = salary;
    }

    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 int getSalary() {
        return salary;
    }

    public void setSalary(int salary) {
        this.salary = salary;
    }

    @Override
    public String toString() {
        return "Person{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", salary=" + salary +
                '}';
    }

}

2、编写测试方法

package com.abcd;

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

public class PersonTest {
    public static void main(String[] args){
        List<Person> people = new ArrayList<>();
        people.add(new Person("AAA",20,100));
        people.add(new Person("BBB",48,109));
        people.add(new Person("CCC",30,109));

        System.out.println(people);
        Collections.sort(people, new Comparator<Person>() {
            @Override
            public int compare(Person o1, Person o2) {

                //salary降序
                int flag= o2.getSalary()- o1.getSalary();
                if (flag==0){
                    //年龄升序
                    return o1.getAge()-o2.getAge();
                }else {
                    return flag;
                }
            }
        });
        System.out.println(people);
    }
}

3、运行结果

[Person{name='AAA', age=20, salary=100}, Person{name='BBB', age=48, salary=109}, Person{name='CCC', age=30, salary=109}]
[Person{name='CCC', age=30, salary=109}, Person{name='BBB', age=48, salary=109}, Person{name='AAA', age=20, salary=100}]