定义一个Employee类
该类包括：
private 成员变量 name ,age,birthday,其中birthday为MyDate类的对象
并为每一个属性定义getter setter方法
定义Mydate类包含：
private 成员变量 year,month,day 并为每一个属性定义getter setter方法创建该Employee类的5个对象，并把这些对象放入TreeSet集合中，分别按以下两种方式对集合中的元素进行排序，并遍历输出
(1)使Employee实现Comparable接口，并按name排序，字典表顺序
(2)创建TreeSet时传入Comparator对象，按生日日期的对员工进行先后顺序排序
1992 - 05 - 12
1992 - 05 - 18
1992 - 07 - 15
1993 - 06 - 15
1998 - 02 - 03
①Emoplyee.java
public class Employee implements Comparable<Employee>{ private String name;; private int age; private MyDate birthday; public Employee(){} public Employee(int age){ this.age = age; } public Employee(String name){this.name = name;} public Employee(String name, int age, MyDate birthday) { this.name = name; this.age = age; this.birthday = birthday; } 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 MyDate getBirthday() { return birthday; } public void setBirthday(MyDate birthday) { this.birthday = birthday; } @Override public int compareTo(Employee e) { if(this.getAge() == e.getAge()) { return this.getName().compareTo(e.getName()); }else{ return this.getAge() - e.getAge(); } } @Override public String toString() { return "Employee{" + "name='" + name + '\'' + ", age=" + age + ", birthday=" + birthday + '}'; }}②MyDate.java
public class MyDate { private int year; private int month; private int day; public MyDate(){ } public MyDate(int year, int month, int day) { this.year = year; this.month = month; this.day = day; } public int getYear() { return year; } public void setYear(int year) { this.year = year; } public int getMonth() { return month; } public void setMonth(int month) { this.month = month; } public int getDay() { return day; } public void setDay(int day) { this.day = day; } @Override public String toString() { return "MyDate{" + "year=" + year + ", month=" + month + ", day=" + day + '}'; }}③Test.java
public class Test { public static void main(String[] args) { //创建TreeSet集合对象 TreeSet<Employee> set = new TreeSet<>(new Comparator<Employee>() {//比较器比较生日 @Override public int compare(Employee o1, Employee o2) { int year = o1.getBirthday().getYear(); int month = o1.getBirthday().getMonth(); int day = o1.getBirthday().getDay(); int year1 = o2.getBirthday().getYear(); int month1 = o2.getBirthday().getMonth(); int day1 = o2.getBirthday().getDay(); int result = year - year1; int result2 = result == 0 ? month - month1 : result ; int result3 = result2 ==0 ? day - day1 : result2; return result3; } }); //创建Empployee对象 Employee e1 = new Employee("zhangsan",20,new MyDate(1992,05,12)); Employee e2 = new Employee("lisi",18,new MyDate(1992,05,18)); Employee e3 = new Employee("wangwu",18,new MyDate(1992,07,15)); Employee e4 = new Employee("zhaoliu",13,new MyDate(1992,05,12)); Employee e5 = new Employee("xuqi",80,new MyDate(1993,06,15)); //把Employee对象放到TreeSet集合中 set.add(e1); set.add(e2); set.add(e3); set.add(e4); set.add(e5); //遍历 for(Employee e : set){ System.out.println(e); } }}测试结果:
