Java学习笔记50:JSONObject与JSONArray的使用

Java不像PHP解析和生产JSON总是一个比较痛苦的过程。但是使用JSONObject和JSONArray会让整个过程相对舒服一些。

需要依赖的包:commons-lang.jar commons-beanutils.jar commons-collections.jar commons-logging.jar  ezmorph.jar json-lib-2.2.2-jdk15.jar

1. 创建一个JSONObject对象:

package com.yunos.tv.video.resource.controller.web;

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"]}

解析JSON字符串:

package com.yunos.tv.video.resource.controller.web;

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) + " ");
}
}
}
}

返回:

UserName:ZHULI
Array:ZHULI Array:30 Array:ALI
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