基于object属性的ArrayList排序[重复]

Question

public class Employee {
    public String name;
    public int age;

    public Employee()
    {

    }

    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;
    }
}

import java.util.ArrayList;

public class EmployeeTest {
    public static void main(String[] args) 
    {
        ArrayList<Employee> empList = new ArrayList<Employee>();
        Employee emp1 = new Employee();
        emp1.setAge(15);
        emp1.setName("Employee1");
        Employee emp2 = new Employee();
        emp2.setAge(10);
        emp2.setName("Employee1");
        empList.add(emp1);
        empList.add(emp2);
        for(Employee emp : empList)
        {
            System.out.println("employee name : " + emp.getName());
            System.out.println("employee age : " + emp.getAge());
        }
    }
}

现在我有一个关于它的问题是，我想根据Employee class age属性对ArrayList进行排序。所以请解释一下我该如何排序。

Answer 1

实现可比接口

class Employee implements Comparable<Employee> {   

在Employee类中添加实现方法Compareto，如下所示：

 @Override
 public int compareTo(Employee other) {
     return this.age - other.age;
 }

然后，您可以像下面这样对列表进行排序：

Collections.sort(empList)