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/JSONArray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后添加一个jsonArray
JSONArray array = jsonObject.getJSONArray("jsonArray");
System.out.println(jsonObject);
System.out.println("返回一个JSONArray对象：" + array);
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 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"}]}
JSONObject 、JSONArray、 JavaBean 、ArrayList 间转换方法
创建java对象：
public class Address {
private String road;
private String streate;
private String provience;
private String no;
//getter setter...
}
1.将json对象转化为java对象
JSONObject jsonObject = JSONObject.fromObject("{\"no\":\"104\",\"provience\":\"陕西\",\"road\":\"高新路\",\"streate\":\"\"}");
Address Address = (Address) JSONObject.toBean(jsonObject,Address.class);
log.info(Address.getNo());
log.info(Address.getStreate());
log.info(Address.getProvience());
log.info(Address.getRoad());
2.将java对象转化为json对象
将java对象转化为json对象：
Address address = new Address();
address.setNo("104");
address.setProvience("陕西");
address.setRoad("高新路");
address.setStreate("");
JSONArray json = JSONArray.fromObject(address);
log.info(json.toString());
将java对象list转化为json对象：
Address address = new Address();
address.setNo("104");
address.setProvience("陕西");
address.setRoad("高新路");
address.setStreate("");
Address address2 = new Address();
address2.setNo("105");
address2.setProvience("陕西");
address2.setRoad("未央路");
address2.setStreate("张办");
List list = new ArrayList();
list.add(address);
list.add(address2);
JSONArray json = JSONArray.fromObject(list);
log.info(json.toString());
3.JSONArray转化为list
JSONObject jsonObject = JSONObject.fromObject("{\"no\":\"104\",\"provience\":\"陕西\",\"road\":\"高新路\",\"streate\":\"\"}");
JSONArray jsonArray = new JSONArray();
jsonArray.add(jsonObject);
jsonArray.add("{\"no\":\"104\",\"provience\":\"陕西\",\"road\":\"高新路\",\"streate\":\"123\"}");
Object object = JSONArray.toList(jsonArray,Address.class);
![json获取数据的三种方式[图]](data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACwAAAAAAQABAAACAkQBADs=)