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;
}
}