java json array 다루기

        // String  -> Jsonobject 으로  변환
        JSONObject jsonObject = new JSONObject(
                 "{ " +
                          "\"name\":\"John\"," +
                          "\"age\":31," +
                          "\"city\":\"New York\"" +
                 "}"
        ); //생성자 인자에 String을 넣어서 변환
        
        =======================================================
        // Map에 데이터 담기
        Map<String, Object> map = new HashMap<>();
        map.put("major", "CS");
        map.put("professor", professor);
        map.put("students", students);
 
        // Map -> JSON
        JSONObject jsonObject = new JSONObject(map);
        =======================================================
        //Jsonobject -> String으로 변환
        String jsonString = jsonObject.toString();
        =======================================================
        
        {"button" : [
         { "name" : "O", "url_mo" : "https://#{url}/view.do?seq=#{laram}&an=Y" , "url_pc" : "https://#{url}/view.do?seq=#{laram}&an=Y" } ,
         { "name" : "X", "url_mo" : "https://#{url}/view.do?seq=#{laram}&an=N" , "url_pc" : "https://#{url}/view.do?seq=#{laram}&an=N" }
        ]}

        List<Map<String,String>> bthPackList = new ArrayList<>();
        try {
            JSONObject jsonAttachment = new JSONObject(attachment);
            JSONArray objBtn = (JSONArray) jsonAttachment.get("button");
            for (int i = 0; i < objBtn.length(); i++) { // Walk through the Array.
                JSONObject btnInfo = objBtn.getJSONObject(i);
                Map<String,String> btnMap = new HashMap();
                btnMap.put("url_mo", btnInfo.get("url_mo").toString() ); 
                bthPackList.add(btnMap);
            }
        }catch (JSONException err){
            logger.debug("err.getMessage() : " + err.getMessage());
        }