从list中随机抽取不同的指定数量的元素组成新list

    * 从list中随机抽取元素 判断并获取新药随机样本数量  
    * @param list  
    * @param randomQuantity 抽取样本数量   (需要抽取的数量)
    * @return  
    */  
   private static List<PRdrugReviewSampleEntity>  createRandomList(List<PRdrugReviewSampleEntity> list, int randomQuantity) {  
       Integer size = list.size();  
       Map map = new HashMap<>();  
       List<PRdrugReviewSampleEntity> listNew = new ArrayList<>();  
       if (randomQuantity >= size) {  
           return list;  
       }else{  
           while(map.size()<randomQuantity){  
               int random = (int) (Math.random() * list.size());  
               if (!map.containsKey(random)) {  
                   map.put(random, "");  
                   listNew.add(list.get(random));  
               }  
           }  
           return listNew;  
       }  
   }