复制代码 代码如下:

class ArrayListTest1 {

public static void main(String[] args) {

ArrayList al = new ArrayList();

al.add("java03");

al.add("java03");

al.add("java01");

al.add("java02");

al.add("java01");

al.add("java02");

al.add("java01");

System.out.println(al);

al = singleElement(al);

System.out.println(al);

}

//返回List合适些

public static ArrayList singleElement(ArrayList al){

//定义一个临时容器

ArrayList newAl = new ArrayList();

//在迭代是循环中next调用一次，就要hasNext判断一次

Iterator it = al.iterator();

while (it.hasNext()){

Object obj = it.next();//next()最好调用一次就hasNext()判断一次否则容易发生异常

if (!newAl.contains(obj))

newAl.add(obj);

}

return newAl;

}

}