一个很奇怪的问题

f(equipmentList.size()!=0){

       

        String [] equipIdArray =new String[3];

       

           for (int i = 0; i < equipmentList.size(); i++) {

          

           Element equipment = (Element)equipmentList.get(i);

          

           String equipCode = equipment.elementText("type_code");

           System.out.println("equipCode :"+equipCode);

          

           /*

           * 用于储存设备信息的数组

           * equipInfoArray [0]存的是type_id  T002

           * equipInfoArray [1]存的是building_id

           * equipInfoArray [2]存的是equip_id

           */

           equipIdArray[0] = equipment.elementText("type_id");

           equipIdArray[1] = equipment.elementText("building_id");

           equipIdArray[2] = equipment.attributeValue("equip_id");

           System.out.println("equip_id :"+equipIdArray[2]);

          

           equipInfoHashMap.put(equipCode,equipIdArray);

          

           equipIdArray[0] = null;

           equipIdArray[1] = null;

           equipIdArray[2] = null;

          

           }

        }

System.out.println("equip_id :"+equipIdArray[2]);这句输出的数据都没有问题，很正常，可是为什么放进hashmap里面的全都是null的？？？