集合训练5
下面的代码输出什么?
已知:Person类按照id和name重写了hashCode和equals方法,问下面代码输出什么?
import java.util.HashSet;
import java.util.Objects;
public class Homework05 {
public static void main(String[] args) {
HashSet set = new HashSet();
Person p1 = new Person(1001,"AA");
Person p2 = new Person(1002,"BB");
set.add(p1);
set.add(p2);
p1.name = "CC";
set.remove(p1);
System.out.println(set);
set.add(new Person(1001,"CC"));
System.out.println(set);
set.add(new Person(1001,"AA"));
System.out.println(set);
}
}
class Person{
private int id;
public String name;
public Person(int id, String name) {
this.id = id;
this.name = name;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Person person = (Person) o;
return id == person.id &&
Objects.equals(name, person.name);
}
@Override
public int hashCode() {
return Objects.hash(id, name);
}
@Override
public String toString() {
return "person{" +
"id=" + id +
", name='" + name + '\'' +
'}';
}
}