一、使用HashSet添加一个String类型的值：

public static void hashSet1(){

HashSet hashSet = new HashSet();

hashSet.add("java001");

hashSet.add("java01");

hashSet.add("java011");

hashSet.add("java002");

hashSet.add("java004");

//使用常用迭代器获取输出内容

Iterator iterator = hashSet.iterator();

while (iterator.hasNext()) {

String next = iterator.next();

System.out.println(next);

}

}

二、使用HashSet添加一个对象：

public static void hashSet2(){

HashSet hashSet = new HashSet();

hashSet.add(new Student("zhangsan1", 21));

hashSet.add(new Student("zhangsan1", 21));

hashSet.add(new Student("zhangsan2", 21));

hashSet.add(new Student("zhangsan3", 23));

hashSet.add(new Student("zhangsan4", 24));

//使用常用迭代器获取值

Iterator iterator = hashSet.iterator();

while (iterator.hasNext()) {

Student next = (Student) iterator.next();

System.out.println(next.getName() + " " + next.getAge());

}

}

上面使用到的Student对象类：

class Student {

private String name;

private int age;

public Student(String name, int age) {

this.name = name;

this.age = age;

}

//复写hashCode方法

@Override

public int hashCode() {

return 60;

}

//复写equals方法

@Override

public boolean equals(Object arg0) {

if (!(arg0 instanceof Student)) {

return false;

}

Student studet = (Student) arg0;

return this.name.equals(studet.name) && this.age == studet.age;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public int getAge() {

return age;

}

public void setAge(int age) {

this.age = age;

}

}

最后使用调用main方法得出结果：

java004

java002

java011

java001

java01

-------------------------

zhangsan1 21

zhangsan2 21

zhangsan3 23

zhangsan4 24