【Java】Treeset实现自定义排序

package birthday;

import java.util.Calendar;

public class Student {

private String name;
private Calendar birthday;
Student(String aname,Calendar date)
{
name=aname;
birthday=date;

}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Calendar getBirthday() {
return birthday;
}
public void setBirthday(Calendar birthday) {
this.birthday = birthday;
}

}

package birthday;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Comparator;
import java.util.Set;
import java.util.TreeSet;

public class ComparatorStudent implements Comparator<Student>{

@Override
public int compare(Student o1, Student o2) {
// TODO Auto-generated method stub
if (o1.getBirthday().equals(o2.getBirthday()))
{
if (o1.getName().compareTo(o2.getName())>0) return 1;
else if (o1.getName().compareTo(o2.getName())<0) return -1;
else return 0;
}
else if (o1.getBirthday().after(o2.getBirthday()))
return 1;
else
return -1;
}
public static void main(String ars[])
{
Set<Student> treeset = new TreeSet<Student>(new ComparatorStudent());
Calendar cal1 = Calendar.getInstance();
Calendar cal2 = Calendar.getInstance();
Calendar cal3 = Calendar.getInstance();
Calendar cal4 = Calendar.getInstance();
cal1.set(1991,5,6);
cal2.set(1992,2,5);
cal3.set(1992,10,12);
cal4.set(1992,2,5);
Student stu1 = new Student ("Mike",cal1);
Student stu2 = new Student ("Jack",cal2);
Student stu3 = new Student ("Lucy",cal3);
Student stu4 = new Student ("Lily",cal4);

treeset.add(stu4);
treeset.add(stu3);
treeset.add(stu2);
treeset.add(stu1);

SimpleDateFormat dateformat = new SimpleDateFormat("yyyy-MM-dd");
for (Student s:treeset)
{
System.out.println(s.getName()+"	出生日期:	"+dateformat.format(s.getBirthday().getTime()));
}
}

}

Mike	出生日期:	1991-06-06
Jack	出生日期:	1992-03-05
Lily	出生日期:	1992-03-05
Lucy	出生日期:	1992-11-12