JSON常用格式大处理

总结了日常开发中对Json格式的处理，需要下载json相关Jar；这里提供下主要Jar
json-lib-2.2.3-jdk13.jar

import net.sf.json.JSON;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
import net.sf.json.xml.XMLSerializer;

/**
 * Json串处理工具类
 * json,list,map等之间的各种转化
 * @author
 * @version 2.0 create at,2009-2-12
 * 
 */
public class JsonUtil {
	/**
	 * 将json格式的字符串转化为jsonobject
	 * @param str
	 * @return
	 * @throws ApplicationException 
	 */
	public static JSONObject stringToJsonObject(String str) throws ApplicationException {
		JSONObject jsonObject = null;
		if (Validator.isNotNull(str)) {
			try{
				jsonObject = JSONObject.fromObject(str);
			}catch(Exception ex){
				throw new ApplicationException("要转化的字符串格式不对，必须为json格式！");
			}
		}
		return jsonObject;
	}

	/**
	 * 从指定的List<map>对象中获取要设置的值后组装成返回给前台的JSON对象字符串.
	 * 主要用于给前台分页grid组装数据
	 * @param list    list<map>从数据库中查询出来的数据
	 * @param count   总数
	 * @return
	 */
	@SuppressWarnings("unchecked")
	public static String fromMap(List list, int count) {
		//将list<map>转化为jsonarray
		JSONArray options = formListArray(list);
		JSONObject result = new JSONObject();
		result.put("result", options);
		result.put("totalCount", count);
		return result.toString();
	}

	/**
	 * 将Map<String,String>转化为JSONObject格式的字符串
	 * @param map
	 * @return {"success":true,"result":{}}
	 */
	public static String fromMapToJson(Map<String, String> map) {
		Iterator<String> it = map.keySet().iterator();
		JSONObject jsonObject = new JSONObject();
		JSONObject json = new JSONObject();
		while (it.hasNext()) {
			String key = (String) it.next();
			jsonObject.put(key.toLowerCase(), map.get(key));
		}
		json.put("success", true);
		json.put("result", jsonObject.toString());
		return json.toString();
	}

	/**
	 * 	将list<map>转化为jsonobject格式的字符串
	 * @param list
	 * @return {"result":{...}}
	 */
	@SuppressWarnings("unchecked")
	public static String fromListMap(List list) {
		JSONArray options = new JSONArray();
		for (Object obj : list) {
			Iterator it = ((Map) obj).keySet().iterator();
			Object value;
			JSONObject option = new JSONObject();
			while (it.hasNext()) {
				String key = (String) it.next();
				value = ((Map) obj).get(key);
				value = value != null ? value : "";
				option.put(key.toLowerCase(), value);
			}
			options.add(option);
		}
		JSONObject result = new JSONObject();
		result.put("result", options.toString());
		return result.toString();
	}

	/**
	 * 从list<map>转化为treenode的json
	 * @param list
	 * @return
	 */
	@SuppressWarnings("unchecked")
	public static String toAsynTreeJson(List list) {
		JSONArray ja = new JSONArray();
		for (Object obj : list) {
			Iterator it = ((Map) obj).keySet().iterator();
			JSONObject option = new JSONObject();
			while (it.hasNext()) {
				String key = (String) it.next();
				Object value = ((Map) obj).get(key);
				key = key.toLowerCase();
				value = value == null ? "" : value.toString();
				//是否含有带checkbox的treenode
				if (key.equals("checked")) {
					boolean check = value.equals("1") ? true : false;
					option.put("checked", check);
				}
				//是为叶子节点还是为非叶子节点
				else if("leaf".equals(key)){
					boolean leaf = value.toString().trim().equals("1")?true:false;
					option.put("leaf", leaf);
				}else if("draggable".equals(key)){
					boolean draggable = value.toString().trim().equals("1")?true:false;
					option.put("draggable", draggable);
				}
				else
					option.put(key, value);
			}
			ja.add(option);
		}
		return ja.toString();
	}

	/**
	 * 将list<map>转化为jsonarray
	 * 此JSONArray的格式将会是这样[{},{}]
	 * @param list 
	 * @return
	 */
	@SuppressWarnings("unchecked")
	public static JSONArray formListArray(List list) {
		JSONArray options = new JSONArray();
		for (Object obj : list) {
			Iterator it = ((Map) obj).keySet().iterator();
			JSONObject option = new JSONObject();
			while (it.hasNext()) {
				String key = (String) it.next();
				Object value = ((Map) obj).get(key);
				value = value != null ? value : "";
				option.put(key.toLowerCase(), value);
			}
			options.add(option);
		}
		return options;
	}
	/**
	 * 从List<Model>转化成jsonArray
	 * list中装的对象为具体的po
	 * @param list
	 * @return
	 */
	@SuppressWarnings("unchecked")
	public static JSONArray formListModelArray(List list){
		JSONArray options = new JSONArray();
		for (Object obj : list) {
			options.add(obj);
		}
		return options;
	}
	/**
	 * 将JSONArray逆向转化为List  list中可以为任何元素，
	 * @param json  符合JSONArray格式的字符串
	 * 				可以是很复杂的格式，如[{},[],{a:[],b:{},c:{cc:[]...}},'test']
	 * @return
	 */
	@SuppressWarnings("unchecked")
	public static List JSONArrayConvertList(String json) {
		ArrayList list = new ArrayList();
		JSONArray ja = JSONArray.fromObject(json);
		populateArray(ja, list);
		return list;
	}

	@SuppressWarnings("unchecked")
	private static void populateArray(JSONArray jsonArray, List list) {
		//循环遍历jsonarray
		for (int i = 0; i < jsonArray.size(); i++) {
			if (jsonArray.get(i).getClass().equals(JSONArray.class)) {  //如果元素是JSONArray类型
				ArrayList _list = new ArrayList();
				list.add(_list);
				//递归遍历，此为深度遍历，先把最内层的jsonobject给遍历了
				populateArray(jsonArray.getJSONArray(i), _list);
			} else if (jsonArray.get(i).getClass().equals(JSONObject.class)) {  //如果是JSONObject类型
				HashMap _map = new HashMap();
				list.add(_map);
				//遍历JSONObject
				populate(jsonArray.getJSONObject(i), _map);
			} else {  //如果都不是的话就直接加入到list中
				list.add(jsonArray.get(i));
			}
		}
	}

	@SuppressWarnings("unchecked")
	private static Map populate(JSONObject jsonObject, Map map) {
		for (Iterator iterator = jsonObject.entrySet().iterator(); iterator
				.hasNext();) {
			String entryStr = String.valueOf(iterator.next());
			String key = entryStr.substring(0, entryStr.indexOf("="));
			if (jsonObject.get(key).getClass().equals(JSONObject.class)) {
				HashMap _map = new HashMap();
				map.put(key, _map);
				populate(jsonObject.getJSONObject(key), _map);
			} else if (jsonObject.get(key).getClass().equals(JSONArray.class)) {
				ArrayList list = new ArrayList();
				map.put(key, list);
				populateArray(jsonObject.getJSONArray(key), list);
			} else {
				map.put(key, jsonObject.get(key));
			}
		}
		return map;
	}

	/**
	 * Map转换成JSONObject
	 * @param map
	 * @return
	 */
	@SuppressWarnings("unchecked")
	public JSONObject populateToJsonObject(Map map) {
		    JSONObject temp = new JSONObject();
		    Iterator iter = map.entrySet().iterator();
		    while (iter.hasNext()) {
		      Entry entry = (Entry) iter.next();
		      String key = entry.getKey().toString();
		      String value = entry.getValue() == null ? "" : entry.getValue().toString();
		      temp.put(key, value);
		    }
		    return temp;
		  }
	/**
	*将json转化为xml
	**/  
	public static String jsonToXml(JSON json,Boolean appendHint){
		XMLSerializer xmlSerializer = new XMLSerializer();
		xmlSerializer.setTypeHintsEnabled(appendHint);
		xmlSerializer.setRootName("root");
		return xmlSerializer.write(json);
	}
	/**
	*将xml转化为json
	**/
	public static JSON xmlToJson(String xml){
		XMLSerializer xmlSerializer = new XMLSerializer();
		JSON json = xmlSerializer.read(xml);
		return json;
	}
	
}