大概念：
JsonObject 其实就是个Map:
JsonArry: 就是一个数组 Aarry;
测试代码粘贴就能测试使用；
public class Testmain { public static void main(String[] args) { String str = "{"name":"gu","num":123456,"sex":"male","age":24}"; JSONObject jsonObject = JSON.parseObject(str); //获取json对象的大小 int size = jsonObject.size(); // 第一种遍历方式 Set setresult = jsonObject.entrySet(); Iterator iterator = setresult.iterator(); while (iterator.hasNext()) { Object value = iterator.next(); System.out.println(value); } // 测试方法2； JsonarryTest(); }// json数组的遍历方式，读取数组的值，遍历数组对象， static void JsonarryTest() { String arry = "[{1:2},{2:3},{3:4},{4:5}]"; // 解析成数组对象，强转一下 JSONArray jsonArray = JSONArray.parseArray(arry); // 获取数组中的对象 Map<String, String> reslut = (Map<String, String>) jsonArray.get(0); // 遍历jsons数组对象， for (int i = 0; i < jsonArray.size(); i++) { Object object = jsonArray.get(i); System.out.println(object.toString()); } System.out.println(jsonArray.toString()); }}
JSONObject解析对象， 直接将对象.class，作为参数写入，就能直接输出对象
之前太Low ,现在才知道。
测试例子：
@Test public void Str2Obj() { String str = "{"changeCode":"2019032610320079c1fa8c","type":"user","opt":3,"before":{"cityCode":"265","areaCode":"10000001","status":1,"isValid":null,"leaders":"2018072712251052dc081d","orgId":"201708021422007c0291bf","jobCode":"sales_assistant"},"after":{"cityCode":"276","areaCode":"10000001","status":1,"isValid":null,"leaders":"2018072712251052dc081d","orgId":"201708021422007c0291bf","jobCode":"sales_assistant"},"time":1562586539428}n"; ChangeBody<EmployeeChangeMsg> changeBody = new ChangeBody<>(); /* EmployeeChangeMsg changeMsg = new EmployeeChangeMsg(); JSONObject jsonObject = JSONObject.parseObject(str); Object changeCode = jsonObject.get("changeCode"); Object opt = jsonObject.get("opt"); Object type = jsonObject.get("type"); JSONObject after = JSONObject.parseObject(jsonObject.get("after").toString()); Object status = after.get("status"); Byte var = Byte.parseByte(status.toString()); Object orgId = after.get("orgId"); Object jobCode = after.get("jobCode");*/ ChangeBody changeBody1 = JSONObject.parseObject(str, changeBody.getClass()); log.info("=====");}