请定义一个存储 Student 类型的 HashSet 集合:
学生类代码:
public class Student {
private String name;
private String sex;
private int age;
public Student() {
}
public Student(String name, String sex, int age) {
this.name = name;
this.sex = sex;
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
@Override
public String toString() {
return "Student{" +
"name='" + name + '\'' +
", sex='" + sex + '\'' +
", age=" + age +
'}';
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Student student = (Student) o;
return age == student.age &&
Objects.equals(name, student.name) &&
Objects.equals(sex, student.sex);
}
@Override
public int hashCode() {
return Objects.hash(name, sex, age);
}
}
测试类代码:
public class Test {
public static void main(String[] args) {
System.out.println("嗨客网(www.haicoder.net)\n");
HashSet<Student> set = new HashSet<>();
Student stu1 = new Student("张三","男",20);
Student stu2 = new Student("李四","男",21);
Student stu3 = new Student("张三","男",20);
// 存储元素
Collections.addAll(set,stu1,stu2,stu3);
// 循环遍历集合
for (Student student : set){
System.out.println(student);
}
}
}
运行结果如下图:
以上案例存储对象到 Set 集合中,由此看出 Set 集合元素不可重复且无序。