Json 常用操作
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
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"}]}
关于java bean的处理
创建java对象：
public class Address {
private String road;
private String streate;
private String provience;
private String no;
public String getRoad() {
return road;
}
public void setRoad(String road) {
this.road = road;
}
public String getStreate() {
return streate;
}
public void setStreate(String streate) {
this.streate = streate;
}
public String getProvience() {
return provience;
}
public void setProvience(String provience) {
this.provience = provience;
}
public String getNo() {
return no;
}
public void setNo(String no) {
this.no = no;
}
}
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("{\"no\":\"104\",\"provience\":\"陕西\",\"road\":\"高新路\",\"streate\":\"\"}");
jsonArray.add("{\"no\":\"104\",\"provience\":\"陕西\",\"road\":\"高新路\",\"streate\":\"123\"}");
Object object = JSONArray.toList(jsonArray,Address.class);