Question

我在Util类中有一些HasMaps。都属于公共静态。我已经通过服务层实例化了它们。但问题是当我使用get方法检索键的值时，它返回null值。但是，如果我打印整个地图，它表明键和值都存在。

Util类：

public class Util_GetGeoCode
  {
    //divsion
//    public static Map<Integer,String> map_division_id = new HashMap();
    public static Map map_division_id = new HashMap();
    //district
    public static Map map_district_id = new HashMap();
    //upzilla
    public static Map map_upozila_id = new HashMap();
    //union
    public static Map map_uinon_id = new HashMap();

    public static void clear_all_maps()
      {
        //test

        System.out.println("clear Map");
        map_division_id.clear();
        map_district_id.clear();
        map_upozila_id.clear();
        map_uinon_id.clear();         
      }
  }//class

将设置地图的代码：

public class BeneficiarySyncManager extends SyncManager
{
    public void execute()
    {
        //other codes

        setAll_locations_geoCode_by_id(moswBeneList);
        System.out.println(" After setting Util_GetGeoCode.map_division_id : "+Util_GetGeoCode.map_division_id);
        Map m = Util_GetGeoCode.map_division_id;
        System.out.println(" m (key) : "+m.keySet());
        System.out.println(" After get : "+Util_GetGeoCode.map_division_id.get(3));


        //other codes

        //clear all the maps of id to geo code
        Util_GetGeoCode.clear_all_maps();
    }

    public void setAll_locations_geoCode_by_id(List list_moswBene)
      {
        //divsion
        Set set_division_id = new HashSet();
        //district
        Set set_district_id = new HashSet();
        //upzilla
        Set set_upozila_id = new HashSet();
        //union
        Set set_uinon_id = new HashSet();

          for (Iterator iterator = list_moswBene.iterator(); iterator.hasNext();)
            {
                Beneficiaries_Mosw next_Mosw = (Beneficiaries_Mosw) iterator.next();

                set_division_id.add(next_Mosw.getPresentDivisionId());
                set_division_id.add(next_Mosw.getPermanentDivisionId());

                set_district_id.add(next_Mosw.getPermanentDistrictId());
                set_district_id.add(next_Mosw.getPresentDistrictId());

                set_upozila_id.add(next_Mosw.getPermanentThanaUpazilaId());
                set_upozila_id.add(next_Mosw.getPresentThanaUpazilaId());

                set_uinon_id.add(next_Mosw.getPermanentUnionWardId());
                set_uinon_id.add(next_Mosw.getPresentUnionWardId());
            }//for (Iterator iterator = set_uinon_id.iterator(); iterator.hasNext();)

          Util_GetGeoCode.map_division_id   = sManager.service_getGeoCode_Divisions(set_division_id);
          Util_GetGeoCode.map_district_id   = sManager.service_getGeoCode_District(set_district_id);
          Util_GetGeoCode.map_upozila_id    = sManager.service_getGeoCode_Thana_Upazilas(set_upozila_id);
          Util_GetGeoCode.map_uinon_id      = sManager.service_getGeoCode_union_wards(set_uinon_id);

          //this line also prin null
          System.out.println(" inside set : Util_GetGeoCode.map_division_id : "+Util_GetGeoCode.map_division_id.get(3));
      }//public void setAll_locations_geoCode_by_id(List list_moswBene)
}//class

输出：

//other messages
inside set : Util_GetGeoCode.map_division_id : null
 After setting Util_GetGeoCode.map_division_id : {3=30}
 m (key) : [3]
 After get : null

但是当我测试时，同样的get方法已经有效了。下面我提供了带输出的测试代码。

测试代码：

 @Test
     public void test_getGeoCode_of_divisions()
       {
         BeneficiaryDao beneficiaryDao = new BeneficiaryDao();
         Set set_division_id = new HashSet();
         set_division_id.add(1);
         set_division_id.add(2);
         set_division_id.add(3);
         Util_GetGeoCode.map_division_id = beneficiaryDao.dao_getGeoCode_Divisions(set_division_id);
         Map map_divGeoCodes = beneficiaryDao.dao_getGeoCode_Divisions(set_division_id);
         System.out.println("\n\nGeoCode of Divs : "+map_divGeoCodes);
         System.out.println(map_divGeoCodes.get(1));
         System.out.println("Util_GetGeoCode.map_division_id : " +Util_GetGeoCode.map_division_id.get(3));
         System.out.println("\n\n");
       }//public void test_getGeoCode_of_divisions()

测试结果： Div的GeoCode：{1 = 10,2 = 20,3 = 30} 10 Util_GetGeoCode.map_division_id：30

哈希映射返回一个键的空值，但键和值都存在于Java

0 个答案: