Map的KEY值转成大写

时间:2025-02-16 10:04:51

 public class OrderBy {
       public static void main(String[] args) {

//新建一个Map类型的List集合

            List<Map<String,String>> list = new ArrayList<Map<String,String>>();
     //将3个Map集合放到  List集合     
            Map<String,String> map = new HashMap<String, String>();
            Map<String,String> map1 = new HashMap<String, String>();
            Map<String,String> map2 = new HashMap<String, String>();
             ("a", "1");
             ("b", "2");
             ("c", "3");
             ("d", "4");
             ("e", "5");
             (map);
             ("a1", "11");
             ("b2", "21");
             ("c3", "31");
             ("d4", "41");
             ("e5", "51");
             (map1);
             ("aa", "12");
             ("ba", "22");
             ("ca", "32");
             ("da", "42");
             ("ea", "52");
             (map2);
         
          
                ("未转换"+list); 

          //再new一个Map类型的List集合放转换大写后的集合

                List<Map<String, Object>> body = new ArrayList<Map<String,Object>>();
              //将集合遍历
                for(int i=0;i<();i++){ 

           //循环new  map集合,

                      Map<String,Object> obdmap = new HashMap<String, Object>();                  

                    Set<String> se = (i).keySet();                                    
                for(String set :se){

                      //在循环将大写的KEY和VALUE 放到新的Map                    

                        ((), (i).get(set));                        
                        
                    }

              //将Map放进List集合里

                 (obdmap);
                }
                ("转换"+body);
      }

}



主要思路
1.用keyset将map的key值取出来,String有个方法叫toUpperCase()可以将String类型转换成大写

2.因为将key转换大写了 ,所以key无法找到对应的value值。用循环的方法将大写的key值和value值放到一个新的map里