【Java学习笔记】<集合框架>定义功能去除ArrayList中的重复元素

 import java.util.ArrayList;
 import java.util.Iterator;

 import cn.itcast.p1.bean.Person;

 public class ArrayListTest2 {

     public static void main(String[] args) {

         ArrayList al = new ArrayList();

         al.add(new Person("lisi1",21));
         al.add(new Person("lisi2",22));  //与28行的Person，内容相同，地址不同
         al.add(new Person("lisi3",23));
         al.add(new Person("lisi4",24));
         al.add(new Person("lisi2",22));
         al.add(new Person("lisi3",23));

         System.out.println(al);

         al = getSingleElement(al);

         System.out.println(al);

         System.out.println(al.remove(new Person("lisi2",22)));//remove内部是用equals来判断删除内容
         System.out.println(al);

     }

     private static ArrayList getSingleElement(ArrayList al) {
         //1.定义一个临时容器
         ArrayList temp = new ArrayList();

         //2.迭代al集合
         Iterator it = al.iterator();

         while (it.hasNext())
         {
             Object obj = it.next();

             //3.判断被迭代到的元素是否在临时容器中存在
             if (!temp.contains(obj))
             {
                 temp.add(obj);
             }
         }

         return temp;
     }

 }