java唯一并且有序

java唯一并且有序"/>

java唯一并且有序

public static  void main(String[] args) {

Stu b1=new Stu(1,"张三",18,"男");

Stu b2=new Stu(9,"神侣",33,"女");

Stu b3=new Stu(4,"大神",111,"男");

Stu b4=new Stu(4,"大神",111,"男");

ArrayList a = new ArrayList();

a.add(b1);

a.add(b2);

a.add(b3);

a.add(b4);

a.add(null);

a.add(null);

Iterator it = a.iterator();

while(it.hasNext()) {

System.out.println(it.next());

}

System.out.println("------------");

List a1 = new LinkedList();

a1.add(b1);

a1.add(b2);

a1.add(b3);

a1.add(b4);

a1.add(null);

a1.add(null);

Iterator it1 = a1.iterator();

while(it1.hasNext()) {

System.out.println(it1.next());

}

结果：

Stu [id=1, name=张三, age=18, sex=男]

Stu [id=9, name=神侣, age=33, sex=女]

Stu [id=4, name=大神, age=111, sex=男]

Stu [id=4, name=大神, age=111, sex=男]

null

null

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

Stu [id=1, name=张三, age=18, sex=男]

Stu [id=9, name=神侣, age=33, sex=女]

Stu [id=4, name=大神, age=111, sex=男]

Stu [id=4, name=大神, age=111, sex=男]

null

null