Java学习笔记50：JSONObject与JSONArray的使用

时间：2022-03-09 03:08:33

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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