json을 map으로, map을 json으로 변환하는 예제들

import java.io.IOException;

import java.util.ArrayList;

import java.util.List;

import java.util.Map;

import org.apache.log4j.Logger;

import org.codehaus.jackson.JsonParseException;

import org.codehaus.jackson.map.JsonMappingException;

import org.codehaus.jackson.map.ObjectMapper;

import org.json.simple.JSONArray;

import org.json.simple.JSONObject;

/**

*    일반문자열 유틸.

*

* @author someone

* @version 1.0.0

*/

public class JsonUtil {

    /**

     * 로그 출력.

     */

    @SuppressWarnings("unused")

    private static Logger logger = Logger.getLogger(JsonUtil.class);

    /**

     * Map을 jsonString으로 변환한다.

     *

     * @param map Map<String, Object>.

     * @return String.

     */

    @SuppressWarnings("unchecked")

    public static JSONObject getJsonStringFromMap( Map<String, Object> map ) {

        JSONObject json = new JSONObject();

        for( Map.Entry<String, Object> entry : map.entrySet() ) {

            String key = entry.getKey();

            Object value = entry.getValue();

            json.put(key, value);

        }

        

        return json;

    }

    

    /**

     * List<Map>을 json으로 변환한다.

     *

     * @param list List<Map<String, Object>>.

     * @return JSONArray.

     */

    @SuppressWarnings("unchecked")

    public static JSONArray getJsonArrayFromList( List<Map<String, Object>> list ) {

        JSONArray jsonArray = new JSONArray();

        for( Map<String, Object> map : list ) {

            jsonArray.add( getJsonStringFromMap( map ) );

        }

        

        return jsonArray;

    }

    

    /**

     * List<Map>을 jsonString으로 변환한다.

     *

     * @param list List<Map<String, Object>>.

     * @return String.

     */

    @SuppressWarnings("unchecked")

    public static String getJsonStringFromList( List<Map<String, Object>> list ) {

        JSONArray jsonArray = new JSONArray();

        for( Map<String, Object> map : list ) {

            jsonArray.add( getJsonStringFromMap( map ) );

        }

        

        return jsonArray.toJSONString();

    }

    /**

     * JsonObject를 Map<String, String>으로 변환한다.

     *

     * @param jsonObj JSONObject.

     * @return String.

     */

    @SuppressWarnings("unchecked")

    public static Map<String, Object> getMapFromJsonObject( JSONObject jsonObj ) {

        Map<String, Object> map = null;

        

        try {

            

            map = new ObjectMapper().readValue(jsonObj.toJSONString(), Map.class) ;

            

        } catch (JsonParseException e) {

            e.printStackTrace();

        } catch (JsonMappingException e) {

            e.printStackTrace();

        } catch (IOException e) {

            e.printStackTrace();

        }

        return map;

    }

    /**

     * JsonArray를 List<Map<String, String>>으로 변환한다.

     *

     * @param jsonArray JSONArray.

     * @return List<Map<String, Object>>.

     */

    public static List<Map<String, Object>> getListMapFromJsonArray( JSONArray jsonArray ) {

        List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();

        

        if( jsonArray != null )

        {

            int jsonSize = jsonArray.size();

            for( int i = 0; i < jsonSize; i++ )

            {

                Map<String, Object> map = JsonUtil.getMapFromJsonObject( ( JSONObject ) jsonArray.get(i) );

                list.add( map );

            }

        }

        

        return list;

    }

}