对象数组的排序的四种方法

public class TestMethodRef {
   //数组引用
   @Test
   public void test(){

      Person[] rosterAsArray = new Person[]
            {
                  new Person(100,"zangliang"),
                  new Person(1,"anan"),
                  new Person(120,"ananma")
            };

//    //使用最原始的方法
//    Arrays.sort(rosterAsArray, new PersonAgeComparator());
//    //使用lamda
//    Arrays.sort(rosterAsArray,
//          (Person a, Person b) -> {
//             return a.age.compareTo(b.age);
//          }
//    );
//    //这种用于比较两个Person实例的出生日期的方法已经存在Person.compareByAge
//    Arrays.sort(rosterAsArray,
//          (a, b) -> Person.compareByAge(a, b)
//    );
//    //可以使用方法引用代替lambda表达式
      Arrays.sort(rosterAsArray, Person::compareByAge);

      for (Person person : rosterAsArray) {
         System.out.println(person.name);
      }

   }



}
class PersonAgeComparator implements Comparator<Person> {
   @Override
   public int compare(Person a, Person b) {
      return a.age.compareTo(b.age);
   }
}

class Person {

   public enum Sex {
      MALE, FEMALE
   }
   public Person(Integer age,String name)
   {
      this.age=age;
      this.name=name;
   }
   String name;
   Calendar birthday;
   Sex gender;
   String emailAddress;
   Integer age;

   public int getAge() {
      return age;
   }

   public Calendar getBirthday() {
      return birthday;
   }

   public static int compareByAge(Person a, Person b) {
      return a.age.compareTo(b.age);
   }}