JSONObject

1. 创建一个JSONObject对象

import java.util.ArrayList;
import java.util.HashMap;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;

public class Test {
public static void main(String[] args) {
//JsonObject和JsonArray区别就是JsonObject是对象形式，JsonArray是数组形式
//创建JsonObject第一种方法
JSONObject jsonObject = new JSONObject();
jsonObject.put("UserName", "ZHULI");
jsonObject.put("age", "30");
jsonObject.put("workIn", "ALI");
System.out.println("jsonObject1：" + jsonObject);

//创建JsonObject第二种方法
HashMap<String, String> hashMap = new HashMap<String, String>();
hashMap.put("UserName", "ZHULI");
hashMap.put("age", "30");
hashMap.put("workIn", "ALI");
System.out.println("jsonObject2：" + JSONObject.fromObject(hashMap));

//创建一个JsonArray方法1
JSONArray jsonArray = new JSONArray();
jsonArray.add(0, "ZHULI");
jsonArray.add(1, "30");
jsonArray.add(2, "ALI");
System.out.println("jsonArray1：" + jsonArray);

//创建JsonArray方法2
ArrayList<String> arrayList = new ArrayList<String>();
arrayList.add("ZHULI");
arrayList.add("30");
arrayList.add("ALI");
System.out.println("jsonArray2：" + JSONArray.fromObject(arrayList));
//如果JSONArray解析一个HashMap，则会将整个对象的放进一个数组的值中
System.out.println("jsonArray FROM HASHMAP：" + JSONArray.fromObject(hashMap));

//组装一个复杂的JSONArray
JSONObject jsonObject2 = new JSONObject();
jsonObject2.put("UserName", "ZHULI");
jsonObject2.put("age", "30");
jsonObject2.put("workIn", "ALI");
jsonObject2.element("Array", arrayList);
System.out.println("jsonObject2：" + jsonObject2);
}
}

结果

jsonObject1：{"UserName":"ZHULI","age":"30","workIn":"ALI"}

jsonObject2：{"workIn":"ALI","age":"30","UserName":"ZHULI"}

jsonArray1：["ZHULI","30","ALI"]

jsonArray2：["ZHULI","30","ALI"]

jsonArray FROM HASHMAP：[{"workIn":"ALI","age":"30","UserName":"ZHULI"}]

jsonObject2：{"UserName":"ZHULI","age":"30","workIn":"ALI","Array":["ZHULI","30","ALI"]}

2.解析JSON字符串：

import net.sf.json.JSONArray;
import net.sf.json.JSONObject;

public class Test {

public static void main(String[] args) {
String jsonString = "{\"UserName\":\"ZHULI\",\"age\":\"30\",\"workIn\":\"ALI\",\"Array\":[\"ZHULI\",\"30\",\"ALI\"]}";
//将Json字符串转为java对象
JSONObject obj = JSONObject.fromObject(jsonString);
//获取Object中的UserName
if (obj.has("UserName")) {
System.out.println("UserName:" + obj.getString("UserName"));
}
//获取ArrayObject
if (obj.has("Array")) {
JSONArray transitListArray = obj.getJSONArray("Array");
for (int i = 0; i < transitListArray.size(); i++) {
System.out.print("Array:" + transitListArray.getString(i) + " ");
}
}
}
}

结果

UserName:ZHULI

Array:ZHULI Array:30 Array:ALI