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