TreeSet的两种排序方式

public class MyDate {
    private int month;
    private int year;
    private int day;
    @Override
    public String toString() {
        return "MyDate{" +
                "month=" + month +
                ", year=" + year +
                ", day=" + day +
                '}';
    }
    public MyDate(int month, int year, int day) {
        this.month = month;
        this.year = year;
        this.day = day;
    }
    public int getMonth() {
        return month;
    }
    public void setMonth(int month) {
        this.month = month;
    }
    public int getYear() {
        return year;
    }
    public void setYear(int year) {
        this.year = year;
    }
    public int getDay() {
        return day;
    }
    public void setDay(int day) {
        this.day = day;
    }
}

public class Employee implements Comparable {
    private String name;
    private int age;
    private MyDate birthday;
    public Employee(String name, int age, MyDate birthday) {
        this.name = name;
        this.age = age;
        this.birthday = birthday;
    }
    public Employee() {
    }
    @Override
    public String toString() {
        return "Employee{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", 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(Object o) {
        if(o instanceof Employee){
            Employee e = (Employee)o;
            return this.name.compareTo(e.name);
        }
        return 0;
    }
}

public class Test1 {
    public static void main(String args[]) {
        TreeSet tree = new TreeSet();
        Employee employee1 = new Employee("yangshijie",20,new MyDate(2001,7,23));
        Employee employee2 = new Employee("yanzhihang",18,new MyDate(2003,1,9));
        Employee employee3 = new Employee("chenkangjia",18,new MyDate(2003,1,9));
        Employee employee4 = new Employee("luoxingzhe",20,new MyDate(2002,7,23));
        Employee employee5 = new Employee("wangwei",20,new MyDate(2001,8,23));
        tree.add(employee1);
        tree.add(employee2);
        tree.add(employee3);
        tree.add(employee4);
        tree.add(employee5);
        Iterator iterator = tree.iterator();
        while (iterator.hasNext()){
            System.out.println(iterator.next());
        }
    }
}

public class Test1 {
    public static void main(String args[]) {
        Comparator com = new Comparator() {
            @Override
            public int compare(Object o1, Object o2) {
                if (o1 instanceof Employee && o2 instanceof Employee){
                    Employee e1 = (Employee)o1;
                    Employee e2 = (Employee)o2;
                    if (e1.getBirthday().getYear()!=e2.getBirthday().getYear()){
                        return e1.getBirthday().getYear()-e2.getBirthday().getYear();
                    }else if(e1.getBirthday().getMonth()!=e2.getBirthday().getMonth()){
                        return e1.getBirthday().getMonth()-e2.getBirthday().getMonth();
                    }else{
                        return e1.getBirthday().getDay()-e2.getBirthday().getDay();
                    }
                }
                throw new RuntimeException("传入数据错误！");
            }
        };
        TreeSet tree = new TreeSet(com);
        Employee employee1 = new Employee("yangshijie",20,new MyDate(2001,7,23));
        Employee employee2 = new Employee("yanzhihang",18,new MyDate(2003,1,9));
        Employee employee3 = new Employee("chenkangjia",18,new MyDate(2003,1,9));
        Employee employee4 = new Employee("luoxingzhe",20,new MyDate(2002,7,23));
        Employee employee5 = new Employee("wangwei",20,new MyDate(2001,8,23));
        tree.add(employee1);
        tree.add(employee2);
        tree.add(employee3);
        tree.add(employee4);
        tree.add(employee5);
        Iterator iterator = tree.iterator();
        while (iterator.hasNext()){
            System.out.println(iterator.next());
        }
    }
}

public class Employee  {
    private String name;
    private int age;
    private MyDate birthday;
    public Employee(String name, int age, MyDate birthday) {
        this.name = name;
        this.age = age;
        this.birthday = birthday;
    }
    public Employee() {
    }
    @Override
    public String toString() {
        return "Employee{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", 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;
    }
}