1.JAR包简介
要使程序可以运行必须引入JSON-lib包，JSON-lib包同时依赖于以下的JAR包：
- commons-lang.jar
- commons-beanutils.jar
- commons-collections.jar
- commons-logging.jar
- ezmorph.jar
- json-lib-2.2.2-jdk15.jar
2.JSONObject对象使用
JSON-lib包是一个beans,collections,maps,java arrays 和XML和JSON互相转换的包。在本例中，我们将使用JSONObject类创建JSONObject对象，然后我们打印这些对象的值。为了使用JSONObject对象，我们要引入"net.sf.json"包。为了给对象添加元素，我们要使用put()方法。
2.1.实例1
package jsontest;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
public class JSONObjectSample {
???// 创建JSONObject对象
???private static JSONObject createJSONObject() {
???????JSONObject jsonObject = new JSONObject();
???????jsonObject.put("username", "huangwuyi");
???????jsonObject.put("sex", "男");
???????jsonObject.put("QQ", "413425430");
???????jsonObject.put("Min.score", new Integer(99));
???????jsonObject.put("nickname", "梦中心境");
???????return jsonObject;
???}
???public static void main(String[] args) {
???????JSONObject jsonObject = JSONObjectSample.createJSONObject();//静待方法，直接通过类名+方法调用
???????// 输出jsonobject对象
???????System.out.println("jsonObject：" + jsonObject);
???????// 判读输出对象的类型
???????boolean isArray = jsonObject.isArray();
???????boolean isEmpty = jsonObject.isEmpty();
???????boolean isNullObject = jsonObject.isNullObject();
???????System.out.println("是否为数组:" + isArray + "， 是否为空:" + isEmpty
???????????????+ "， isNullObject:" + isNullObject);
???????// 添加属性，在jsonObject后面追加元素。
???????jsonObject.element("address", "福建省厦门市");
???????System.out.println("添加属性后的对象：" + jsonObject);
???????// 返回一个JSONArray对象
???????JSONArray jsonArray = new JSONArray();
???????jsonArray.add(0, "this is a jsonArray value");
???????jsonArray.add(1, "another jsonArray value");
???????jsonObject.element("jsonArray", jsonArray);
???????//在jsonObject后面住家一个jsonArray
???????JSONArray array = jsonObject.getJSONArray("jsonArray");
???????System.out.println(jsonObject);
???????
???????
???????System.out.println("返回一个JSONArray对象：" + array);
???????// 添加JSONArray后的值
???????// {"username":"huangwuyi","sex":"男","QQ":"413425430","Min.score":99,"nickname":"梦中心境","address":"福建省厦门市","jsonArray":["this is a jsonArray value","another jsonArray value"]}
???????System.out.println("结果=" + jsonObject);
???????// 根据key返回一个字符串
???????String username = jsonObject.getString("username");
???????System.out.println("username==>" + username);
???????// 把字符转换为 JSONObject
???????String temp = jsonObject.toString();
???????JSONObject object = JSONObject.fromObject(temp);
???????// 转换后根据Key返回值
???????System.out.println("qq=" + object.get("QQ"));
???}
}
输出结果
jsonObject：{"username":"huangwuyi","sex":"男","QQ":"413425430","Min.score":99,"nickname":"梦中心境"}
是否为数组:false， 是否为空:false， isNullObject:false
添加属性后的对象：{"username":"huangwuyi","sex":"男","QQ":"413425430","Min.score":99,"nickname":"梦中心境","address":"福建省厦门市"}
{"username":"huangwuyi","sex":"男","QQ":"413425430","Min.score":99,"nickname":"梦中心境","address":"福建省厦门市","jsonArray":["this is a jsonArray value","another jsonArray value"]}
返回一个JSONArray对象：["this is a jsonArray value","another jsonArray value"]
结果={"username":"huangwuyi","sex":"男","QQ":"413425430","Min.score":99,"nickname":"梦中心境","address":"福建省厦门市","jsonArray":["this is a jsonArray value","another jsonArray value"]}
username==>huangwuyi
qq=4134254302.2.实例2.
package jsontest;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
public class JSONTest {
???public static void main(String args[])
???{
???????JSONObject jsonObj0 ?= new JSONObject();
???????JSONObject jsonObj ?= new JSONObject();
???????JSONObject jsonObj2 ?= new JSONObject();
???????JSONObject jsonObj3 ?= new JSONObject();
???????JSONArray jsonArray = new JSONArray();
???????
???????//创建jsonObj0
???????jsonObj0.put("name0", "zhangsan");
???????jsonObj0.put("sex1", "female");
???????System.out.println("jsonObj0:"+jsonObj0);
???????
???????//创建jsonObj1
???????jsonObj.put("name", "xuwei");
???????jsonObj.put("sex", "male");
???????System.out.println("jsonObj:"+jsonObj);
???
???????//创建jsonObj2，包含两个条目，条目内容分别为jsonObj0，jsonObj1
???????jsonObj2.put("item0", jsonObj0);
???????jsonObj2.put("item1", jsonObj);
???????System.out.println("jsonObj2:"+jsonObj2);
???????
???????//创建jsonObj3，只有一个条目，内容为jsonObj2
???????jsonObj3.element("j3", jsonObj2);
???????System.out.println("jsonObj3:"+jsonObj3);
???
???????//往JSONArray中添加JSONObject对象。发现JSONArray跟JSONObject的区别就是JSONArray比JSONObject多中括号[]
???????jsonArray.add(jsonObj);
???????System.out.println("jsonArray:"+jsonArray);
???????
???????JSONObject jsonObj4 ?= new JSONObject();
???????jsonObj4.element("weather", jsonArray);
???????System.out.println("jsonObj4:"+jsonObj4);
???}
}
输出结果：
jsonObj0:{"name0":"zhangsan","sex1":"female"}
jsonObj:{"name":"xuwei","sex":"male"}
jsonObj2:{"item0":{"name0":"zhangsan","sex1":"female"},"item1":{"name":"xuwei","sex":"male"}}
jsonObj3:{"j3":{"item0":{"name0":"zhangsan","sex1":"female"},"item1":{"name":"xuwei","sex":"male"}}}
jsonArray:[{"name":"xuwei","sex":"male"}]
jsonObj4:{"weather":[{"name":"xuwei","sex":"male"}]}json：JSONObject与JSONArray的使用
原文地址：http://www.cnblogs.com/dengyungao/p/7509094.html