Java中List集合去除重复数据的方法-蒲公英云

Java中List集合去除重复数据的方法

Myth丶恋晨 2024-02-19 14:33 187阅读 0赞

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;

}

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;

}

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;  
    }