1.JAR包簡介
要使程式可以運作必須引入JSON-lib包，JSON-lib包同時依賴于以下的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對象使用
JSON-lib包是一個beans,collections,maps,java arrays 和XML和JSON互相轉換的包。在本例中，我們将使用JSONObject類建立JSONObject對象，然後我們列印這些對象的值。為了使用 JSONObject對象，我們要引入"net.sf.json"包。為了給對象添加元素，我們要使用put()方法。
2.1.執行個體1
package jsontest;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
public class JSONObjectSample {
// 建立JSONObject對象
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", "夢中心境");
return jsonObject;
}
public static void main(String[] args) {
JSONObject jsonObject = JSONObjectSample.createJSONObject();//靜待方法，直接通過類名+方法調用
// 輸出jsonobject對象
System.out.println("jsonObject：" + jsonObject);
// 判讀輸出對象的類型
boolean isArray = jsonObject.isArray();
boolean isEmpty = jsonObject.isEmpty();
boolean isNullObject = jsonObject.isNullObject();
System.out.println("是否為數組:" + isArray + "， 是否為空:" + isEmpty
+ "， isNullObject:" + isNullObject);
// 添加屬性，在jsonObject後面追加元素。
jsonObject.element("address", "福建省廈門市");
System.out.println("添加屬性後的對象：" + jsonObject);
// 傳回一個JSONArray對象
JSONArray jsonArray = new JSONArray();
jsonArray.add(0, "this is a jsonArray value");
jsonArray.add(1, "another jsonArray value");
jsonObject.element("jsonArray", jsonArray);
//在jsonObject後添加一個jsonArray
JSONArray array = jsonObject.getJSONArray("jsonArray");
System.out.println(jsonObject);
System.out.println("傳回一個JSONArray對象：" + array);
System.out.println("結果=" + jsonObject);
// 根據key傳回一個字元串
String username = jsonObject.getString("username");
System.out.println("username==>" + username);
// 把字元轉換為 JSONObject
String temp = jsonObject.toString();
JSONObject object = JSONObject.fromObject(temp);
// 轉換後根據Key傳回值
System.out.println("qq=" + object.get("QQ"));
}
} 輸出結果
jsonObject：{"username":"huangwuyi","sex":"男","QQ":"413425430","Min.score":99,"nickname":"夢中心境"}
是否為數組:false， 是否為空:false， isNullObject:false
添加屬性後的對象：{"username":"huangwuyi","sex":"男","QQ":"413425430","Min.score":99,"nickname":"夢中心境","address":"福建省廈門市"}
{"username":"huangwuyi","sex":"男","QQ":"413425430","Min.score":99,"nickname":"夢中心境","address":"福建省廈門市","jsonArray":["this is a jsonArray value","another jsonArray value"]}
傳回一個JSONArray對象：["this is a jsonArray value","another jsonArray value"]
結果={"username":"huangwuyi","sex":"男","QQ":"413425430","Min.score":99,"nickname":"夢中心境","address":"福建省廈門市","jsonArray":["this is a jsonArray value","another jsonArray value"]}
username==>huangwuyi
qq=413425430 2.2.執行個體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();
//建立jsonObj0
jsonObj0.put("name0", "zhangsan");
jsonObj0.put("sex1", "female");
System.out.println("jsonObj0:"+jsonObj0);
//建立jsonObj1
jsonObj.put("name", "xuwei");
jsonObj.put("sex", "male");
System.out.println("jsonObj:"+jsonObj);
//建立jsonObj2，包含兩個條目，條目内容分别為jsonObj0，jsonObj1
jsonObj2.put("item0", jsonObj0);
jsonObj2.put("item1", jsonObj);
System.out.println("jsonObj2:"+jsonObj2);
//建立jsonObj3，隻有一個條目，内容為jsonObj2
jsonObj3.element("j3", jsonObj2);
System.out.println("jsonObj3:"+jsonObj3);
//往JSONArray中添加JSONObject對象。發現JSONArray跟JSONObject的差別就是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);
}
} 輸出結果：
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 間轉換方法
建立java對象：
public class Address {
private String road;
private String streate;
private String provience;
private String no;
//getter setter...
}
1.将json對象轉化為java對象
JSONObject jsonObject = JSONObject.fromObject("{\"no\":\"104\",\"provience\":\"陝西\",\"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對象轉化為json對象
将java對象轉化為json對象：
Address address = new Address();
address.setNo("104");
address.setProvience("陝西");
address.setRoad("高新路");
address.setStreate("");
JSONArray json = JSONArray.fromObject(address);
log.info(json.toString());
将java對象list轉化為json對象：
Address address = new Address();
address.setNo("104");
address.setProvience("陝西");
address.setRoad("高新路");
address.setStreate("");
Address address2 = new Address();
address2.setNo("105");
address2.setProvience("陝西");
address2.setRoad("未央路");
address2.setStreate("張辦");
List list = new ArrayList();
list.add(address);
list.add(address2);
JSONArray json = JSONArray.fromObject(list);
log.info(json.toString());
3.JSONArray轉化為list
JSONObject jsonObject = JSONObject.fromObject("{\"no\":\"104\",\"provience\":\"陝西\",\"road\":\"高新路\",\"streate\":\"\"}");
JSONArray jsonArray = new JSONArray();
jsonArray.add(jsonObject);
jsonArray.add("{\"no\":\"104\",\"provience\":\"陝西\",\"road\":\"高新路\",\"streate\":\"123\"}");
Object object = JSONArray.toList(jsonArray,Address.class);
![json擷取資料的三種方式[圖]](data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACwAAAAAAQABAAACAkQBADs=)