【Java学习笔记】<集合框架>定义功能去除ArrayList中的重复元素

 1 import java.util.ArrayList;
 2 import java.util.Iterator;
 3 
 4 import cn.itcast.p1.bean.Person;
 5 
 6 public class ArrayListTest2 {
 7 
 8     public static void main(String[] args) {
 9 
10         
11         ArrayList al = new ArrayList();
12         
13         al.add(new Person("lisi1",21));
14         al.add(new Person("lisi2",22));  //与28行的Person，内容相同，地址不同
15         al.add(new Person("lisi3",23));
16         al.add(new Person("lisi4",24));
17         al.add(new Person("lisi2",22));
18         al.add(new Person("lisi3",23));
19         
20         System.out.println(al);
21         
22         al = getSingleElement(al);
23         
24         System.out.println(al);
25         
26         System.out.println(al.remove(new Person("lisi2",22)));//remove内部是用equals来判断删除内容
27         System.out.println(al);
28 
29     }
30 
31     
32 
33     private static ArrayList getSingleElement(ArrayList al) {
34         //1.定义一个临时容器
35         ArrayList temp = new ArrayList();
36         
37         //2.迭代al集合
38         Iterator it = al.iterator();
39         
40         while (it.hasNext())
41         {
42             Object obj = it.next();
43             
44             //3.判断被迭代到的元素是否在临时容器中存在
45             if (!temp.contains(obj))
46             {
47                 temp.add(obj);
48             }
49         }
50         
51         return temp;
52     }
53 
54 }