JSONObject与JSONArray的使用

jopen 8年前

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"));        }    }

</div>

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

</div>

2.2.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"}]}

</pre> </div>