1 public class CollectionTest {

 2

 3     @Test

 4     public void test3(){

 5         HashSet set = new HashSet();

 6         Person p1 = new Person(1001,"AA");

 7         Person p2 = new Person(1002,"BB");

 8

 9         set.add(p1);

10         set.add(p2);

11         System.out.println(set);

12         //输出2个值[person={1001,"AA"},person={1002,"BB"}]

13

14         p1.name = "CC";

15         set.remove(p1);

16         System.out.println(set);

17         //输出两个值[person={1001,"CC"},person={1001,"BB"}]

18

19         set.add(new Person(1001,"CC"));

20         System.out.println(set);

21         //输出三个值  [person={1001,"CC"},person={1002,"BB"},person={1001,"CC"]

22

23         set.add(new Person(1001,"AA"));

24         System.out.println(set);

25         //输出四个值 [person={1001,"CC"},person={1002,"BB"},person={1001,"CC"，person={1001,"AA"]

26

27     }

28 }