【java编程】Collection类之ArrayList去除重复元素

import java.util.*;class  ArrayListDemo{public static void main(String[] args) {ArrayList al=new ArrayList();al.add("java01");al.add("java02");al.add("java02");al.add("java02");al.add("java03");al.add("java04");al.add("java04");System.out.println(al);System.out.println(singleElement(al));}public static ArrayList singleElement(ArrayList al){//定义一个临时容器ArrayList newAl = new ArrayList();Iterator it=al.iterator();while(it.hasNext()){Object obj = it.next();if(!newAl.contains(obj))newAl.add(obj);}return newAl;}}