package com.fh.util;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
/**
*
* @author donald
*
*/
public class JsonUtil {
/**
* 对象转换成JSON字符串 obj
* @param obj 需要转换的对象
* @return 对象的string字符
*/
public static String toJson(Object obj) {
JSONObject jSONObject = JSONObject.fromObject(obj);
return jSONObject.toString();
}
/**
* just for String[]
* @param obj
* @return
*/
public static String ArraytoJson(Object obj) {
JSONArray jsonArr = JSONArray.fromObject(obj);
return jsonArr.toString();
}
/**
* JSON字符串转换成对象
* @param jsonString 需要转换的字符串
* @param type 需要转换的对象类型
* @return 对象
*/
@SuppressWarnings("unchecked")
public static T fromJson(String jsonString, Class type) {
JSONObject jsonObject = JSONObject.fromObject(jsonString);
return (T) JSONObject.toBean(jsonObject, type);
}
public static String ListToJson(List lobj){
JSONArray jsonArr = JSONArray.fromObject(lobj);
return jsonArr.toString();
}
/**
* 根据json String 返回List
* @param json
* @return
*/
public static List
测试类
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import entity.Cat;
import util.JsonUtil;
public class testJson {
public static void main(String[] args){
Map bmap = new HashMap();
bmap.put("user", "donald");
bmap.put("age", "32");
String bString = JsonUtil.toJson(bmap);
System.out.println("============map:"+bString);
Map bmaps = JsonUtil.jsonToMap(bString);
System.out.println("============user:"+bmaps.get("user"));
System.out.println("============age:"+bmaps.get("age"));
Cat cat1 = new Cat(4,"mini");
String cString = JsonUtil.toJson(cat1);
System.out.println("============Cat:"+cString);
Cat cat2 = JsonUtil.fromJson(cString, Cat.class);
System.out.println("============legs:"+cat2.getLegs());
System.out.println("============name:"+cat2.getName());
cat2.setLegs(5);
cat2.setName("big");
List catList = new ArrayList();
catList.add(cat1);
catList.add(cat2);
String clString = JsonUtil.ListToJson(catList);
System.out.println("============CatList:"+clString);
List catListx= JsonUtil.jsonToList(clString,Cat.class);
Cat cat3 = catListx.get(0);
System.out.println("============legs:"+cat3.getLegs());
System.out.println("============name:"+cat3.getName());
}
}
结果输出：
============map:{"age":"32","user":"donald"}
============user:donald
============age:32
============Cat:{"legs":4,"name":"mini"}
============legs:4
============name:mini
============CatList:[{"legs":4,"name":"mini"},{"legs":5,"name":"big"}]
============legs:4
============name:mini