1、新建一个Student类
package cn.myapp.test;
public class Student {
private String name;
private Integer age;
public Student(){}
public Student(String name,Integer age){
this.name = name;
this.age = age;
}
//省略了getter和setter方法
@Override
public String toString() {
return "Student [name=" + name + ", age=" + age + "]";
}
}
2、写一个main方法测试
package cn.myapp.test;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
public class TestMain {
public static void main(String[] args) throws Exception {
List<Student> students = new ArrayList<Student>();
Student s1 = new Student("张三", 13);
Student s2 = new Student("张三", 12);
Student s3 = new Student("张三", 15);
Student s4 = new Student("张三", 11);
Student s5 = new Student("张三", 18);
students.add(s1);
students.add(s2);
students.add(s3);
students.add(s4);
students.add(s5);
Collections.sort(students,new Comparator<Student>() {
public int compare(Student s1,Student s2){
return s1.getAge() - s2.getAge(); //按照年龄升序;
//如果是 s2.getAge() - s1.getAge()则为降序
}
});
System.out.println(students);
}
}