Java中List集合去除重复数据的方法

Myth丶恋晨 2024-02-19 14:33 9阅读 0赞

1. 循环list中的所有元素然后

public   static   List  removeDuplicate(List list)  {       
      for  ( int  i  =   0 ; i  <  list.size()  -   1 ; i ++ )  {       
          for  ( int  j  =  list.size()  -   1 ; j  >  i; j -- )  {       
               if  (list.get(j).equals(list.get(i)))  {       
                  list.remove(j);       
                }        
            }        
          }        
        return list;       
    }

2. 通过HashSet踢除重复元素

public static List removeDuplicate(List list) {   
        HashSet h = new HashSet(list);   
        list.clear();   
        list.addAll(h);   
        return list;   
    }

3. 删除ArrayList中重复元素，保持顺序

// 删除ArrayList中重复元素，保持顺序     
     public static void removeDuplicateWithOrder(List list) {    
        Set set = new HashSet();    
         List newList = new ArrayList();    
       for (Iterator iter = list.iterator(); iter.hasNext();) {    
             Object element = iter.next();    
             if (set.add(element))    
                newList.add(element);    
          }     
         list.clear();    
         list.addAll(newList);    
        System.out.println( " remove duplicate " + list);    
     }

4.把list里的对象遍历一遍，用list.contain()，如果不存在就放入到另外一个list集合中

public static List removeDuplicate(List list){  
            List listTemp = new ArrayList();  
            for(int i=0;i<list.size();i++){  
                if(!listTemp.contains(list.get(i))){  
                    listTemp.add(list.get(i));  
                }  
            }  
            return listTemp;  
        }

转载：[https://www.cnblogs.com/cainiao-Shun666/p/7911142.html][https_www.cnblogs.com_cainiao-Shun666_p_7911142.html]

[https_www.cnblogs.com_cainiao-Shun666_p_7911142.html]: https://www.cnblogs.com/cainiao-Shun666/p/7911142.html