list集合中按照指定属性排序

package Listpx;
/**
 * 定义一个Employee类,
 * 属性:name:String,age:int,salary:double 
 *  把若干Employee对象放在List中,
 *  排序并遍历输出,
 *  排序规则:salary高的在前面,salary相同时age大的在前面,
 *  age也相同时按照name升序排列
 *  把若干Employee对象放在Set中并遍历,要求没有重复元素
 * @author Administrator
 *
 */
public class Employee {
    private String name;
    private int age;
    private double 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 double getSalary() {
        return salary;
    }
    public void setSalary(double salary) {
        this.salary = salary;
    }
    public Employee(String name,int age,double salary) {
        super();
        this.name = name;
        this.age = age;
        this.salary = salary;
    }
    @Override
    public String toString() {
        return "姓名：" + name + ", 年龄：" + age + ", 工资：" + salary + "]";
    }


}

package Listpx;

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class Etest {
    public static List<Employee> list=new ArrayList<Employee>();
    public static Scanner sc=new Scanner(System.in);
    public static void main(String[] args) {
        list.add(new Employee("zhangsan", 20, 3000));// j
        list.add(new Employee("lisi", 12, 4000));// j+1
        list.add(new Employee("wangwu", 12, 5000));
        list.add(new Employee("zhaoliu", 20, 3000));
        list.add(new Employee("tianqi", 20, 7000));
        list.add(new Employee("张三", 25, 6000));
        list.add(new Employee("zhangsanfeng", 20, 7000));
        list.add(new Employee("张三", 12, 8000));
        //给集合list冒泡排序
        for (int i = 0; i < list.size()-1; i++) {
            for (int j = 0; j < list.size()-i-1; j++) {
                Employee e1=list.get(j);
                Employee e2=list.get(j+1);
                if(e1.getSalary()<e2.getSalary()){
                    list.set(j, e2);//将对象e2放在索引为j的位置
                    list.set(j+1, e1);//将对象e1放在索引为j+1的位置
                }else if(e1.getSalary()==e2.getSalary()){
                    if(e1.getAge()<e2.getAge()){
                        list.set(j, e2);
                        list.set(j+1, e1);
                    }else if(e1.getAge()==e2.getAge()){
                        if(e1.getName().compareTo(e2.getName())>0){
                            //compareTo比较字符串在字典中的先后顺序，前面的顺序靠后就大于0
                            list.set(j, e2);
                            list.set(j+1, e1);
                        }
                    }

                }
            }

        }
        for (Employee e : list) {
            System.out.println(e);

        }
    }

}