JSONObject学习

一、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
二、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，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：
     1.json转换为map
     JSONObject jsonObject = JSONObject.fromObject("{\"name\":\"kevin\",\"Max.score\":100,\"Min.score\":50}");
     System.out.println(jsonObject);//{"name":"kevin","Max.score":100,"Min.score":50}
     String name = (String)((Map)jsonObject).get("name");
     System.out.println(name);//kevin
     2.创建JSONObject对象
      JSONObject jsonObject = new JSONObject();  
     jsonObject.put("name", "kevin");  
     jsonObject.put("Max.score", new Integer(100));  
     jsonObject.put("Min.score", new Integer(50));  
     jsonObject.put("nickname", "picglet");
     System.out.println(jsonObject);//{"name":"kevin","Max.score":100,"Min.score":50,"nickname":"picglet"}
     3.JSONObject对象类型的判断
      boolean isArray = jsonObject.isArray();  
     boolean isEmpty = jsonObject.isEmpty();  
     boolean isNullObject = jsonObject.isNullObject();  
     System.out.println("isArray:"+isArray+" isEmpty:"+isEmpty+" isNullObject:"+isNullObject);//isArray:false isEmpty:false isNullObject:false
     4.JSONObject对象添加属性
      jsonObject.element("address", "swap lake");  
     System.out.println(jsonObject);//{"name":"kevin","Max.score":100,"Min.score":50,"nickname":"picglet","address":"swap lake"}
     5.JSONObject对象添加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);  
     System.out.println(jsonObject);//{"name":"kevin","Max.score":100,"Min.score":50,"nickname":"picglet","address":"swap lake","jsonArray":["this is a jsonArray value","another jsonArray value"]}
     6.根据key和index取JSONObject、JSONArray的值
      String name = jsonObject.getString("name");
     System.out.println(name);//kevin
     int score = jsonObject.getInt("Max.score");
     System.out.println(score);//100
     JSONArray array = jsonObject.getJSONArray("jsonArray");
     System.out.println(array);//["this is a jsonArray value","another jsonArray value"]
     String arrayOneElement = array.getString(0);
     System.out.println(arrayOneElement);//this is a jsonArray value
     7.JSONObject添加布尔值和取布尔值
      JSONObject jsonObject2 = new JSONObject();
     jsonObject2.put("isFlox",true);//{"isFlox":true}
     boolean isFlox = jsonObject2.getBoolean("isFlox");
     System.out.println(isFlox);//true