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; }
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","nickname":"梦中心境","address":"福建省厦门市"} {"username":"huangwuyi","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","another jsonArray value"]} username==>huangwuyi qq=413425430
2.2.实例2
class JSONTest { 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","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","streate":""}"); JSONArray jsonArray = new JSONArray(); jsonArray.add(jsonObject); jsonArray.add("{"no":"104","streate":"123"}"); Object object = JSONArray.toList(jsonArray,Address.class); (编辑:李大同)
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