JSONObject与JSONArray的使用

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  • Post category:其他


参考文献:


http://blog.csdn.net/huangwuyi/article/details/5412500

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:

  1. commons-lang.jar
  2. commons-beanutils.jar
  3. commons-collections.jar
  4. commons-logging.jar
  5. ezmorph.jar
  6. 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=413425430

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"}]}