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.xxx.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.xxx.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
对象遍历
- if (!obj.isNull("sku")) {
- HashMap<String, String> skuMap = new HashMap<String, String>();
- JSONObject skuObject = obj.getJSONObject("sku");
- Iterator<String> keys = skuObject.keys();
- String key;
- Object o;
- while (keys.hasNext()) {
- key = keys.next();
- o = skuObject.get(key);
- skuMap.put(key, String.valueOf(o));
- }
- }