Java超全Json工具类JsonUtil

import java.io.StringReader;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;

import com.anxin.ssk.util.json.ListBean;
import com.anxin.ssk.util.json.MapBean;
import com.sdicons.json.mapper.JSONMapper;
import com.sdicons.json.mapper.MapperException;
import com.sdicons.json.model.JSONArray;
import com.sdicons.json.model.JSONValue;
import com.sdicons.json.parser.JSONParser;

/**
 * JSON工具类
 *
 */
public class JSonUtil {

	/**
	 * JAVA对象转换成JSON字符串
	 * 
	 * @param obj JAVA对象
	 * @return JSON字符串
	 * @throws MapperException
	 */
	public static String obj2Json(Object obj) throws MapperException {
		return obj2Json(obj, false);
	}

	/**
	 * JAVA数组对象转换成JSON字符串
	 * 
	 * @param list JAVA数组对象
	 * @return JSON字符串
	 * @throws MapperException
	 */
	public static String obj2Json(List<Class<?>> list) throws MapperException {
		if (list == null || list.size() == 0) {
			return "{}";
		}
		StringBuilder jsonString = new StringBuilder();
		for (int i = 0; i < list.size(); i++) {
			if (i != 0) {
				jsonString.append(",");
			}
			Class<?> cla = list.get(i);
			jsonString.append(obj2Json(cla, false));
		}
		return jsonString.toString();
	}

	/**
	 * JAVA集合对象转换成JSON字符串
	 * 
	 * @param map JAVA集合对象
	 * @return JSON字符串
	 * @throws MapperException
	 */
	public static String obj2Json(Map<String, Class<?>> map) throws MapperException {
		if (map == null || map.size() == 0) {
			return "{}";
		}
		StringBuilder jsonString = new StringBuilder();
		Set<String> keySet = map.keySet();
		boolean isFirst = true;
		for (String key : keySet) {
			if (isFirst) {
				isFirst = false;
			} else {
				jsonString.append(",");
			}
			Class<?> cla = map.get(key);
			jsonString.append(obj2Json(cla, false));
		}
		return jsonString.toString();
	}
	
	/**
	 * JAVA集合对象转换成JSON字符串
	 * 
	 * @param map JAVA集合对象
	 * @return JSON字符串
	 * @throws MapperException
	 */
	@SuppressWarnings("unchecked")
	public static String map2Json(Map<?,?> map) throws MapperException {
		MapBean mapBean = new MapBean((Map<String, Object>)map);
		return obj2Json(mapBean);
	}

	/**
	 * JAVA数组对象转换成JSON字符串
	 * 
	 * @param list JAVA数组对象
	 * @return JSON字符串
	 * @throws MapperException
	 */
	public static String list2Json(List<?> list) throws MapperException {
		ListBean listBean = new ListBean(list);
		return obj2Json(listBean);
	}

	/**
	 * 重载objectToJsonStr方法
	 * 
	 * @param obj 需要转换的JAVA对象
	 * @param format 是否格式化
	 * @return JSON字符串
	 * @throws MapperException
	 */
	public static String obj2Json(Object obj, boolean format) throws MapperException {
		JSONValue jsonValue = JSONMapper.toJSON(obj);
		String jsonStr = jsonValue.render(format);
		return jsonStr;
	}

	/**
	 * JSON字符串转换成JAVA对象
	 * 
	 * @param jsonStr JSON字符串
	 * @param cla JAVA对象
	 * @return 转换后的对象
	 */
	public static Object json2Obj(String jsonStr, Class<?> cla) throws Exception {
		Object obj = null;
		try {
			JSONParser parser = new JSONParser(new StringReader(jsonStr));
			JSONValue jsonValue = parser.nextValue();
			if (jsonValue instanceof com.sdicons.json.model.JSONArray) {
				List<Object> list = new ArrayList<Object>();
				JSONArray jsonArray = (JSONArray) jsonValue;
				for (int i = 0; i < jsonArray.size(); i++) {
					JSONValue jsonObj = jsonArray.get(i);
					Object javaObj = JSONMapper.toJava(jsonObj, cla);
					list.add(javaObj);
				}
				obj = list;
			} else if (jsonValue instanceof com.sdicons.json.model.JSONObject) {
				obj = JSONMapper.toJava(jsonValue, cla);
			} else {
				obj = jsonValue;
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		return obj;
	}

}