json数组对象实体类list集合 json怎样解析混合数组对象到实体类的list集合里去
老周聊架构 人气:0想了解json怎样解析混合数组对象到实体类的list集合里去的相关内容吗，老周聊架构在本文为您仔细讲解json数组对象实体类list集合的相关知识和一些Code实例，欢迎阅读和指正，我们先划重点：json,混合数组对象,实体类,list集合，下面大家一起来学习吧。
一、前言
这次项目中遇到了一个这样的需求，把下面数据解析到我下面的对象里去。
json 文件
[
{
"categories": [
"美食，小吃快餐"
],
"coordinate": {
"address": "王府井大街138号新东安广场3层328",
"area": "东安市场",
"area_id": "jk238eewf0k",
"city": "北京市",
"city_code": "110100",
"district": "东城区",
"district_code": "110101",
"floor": "3",
"latitude": "39.91456",
"longitude": "116.41155",
"province": "北京市",
"province_code": "110000"
},
"name": "探鱼",
"phone": "010-65280328",
"poi_id": "d7s8f6s6212"
},
{
"categories": [
"美食，面包甜点"
],
"coordinate": {
"address": "丰台北路18号院恒泰广场F6楼",
"area": "恒泰广场",
"area_id": "ji8sgg3b32o",
"city": "北京市",
"city_code": "110100",
"district": "丰台区",
"district_code": "110106",
"floor": "6",
"latitude": "39.86608",
"longitude": "116.30516",
"province": "北京市",
"province_code": "110000"
},
"name": "好客来",
"phone": "010-65280221",
"poi_id": "3g97sg8sd67"
}
]
实体对象：
public class LocatorData {
// 分类
private String categories;
// 商圈
private String area;
// 商圈id
private String areaId;
// 省份
private String province;
// 省份code
private String provinceCode;
// 城市
private String city;
// 城市code
private String cityCode;
// 区县
private String district;
// 区县code
private String districtCode;
// 楼层
private String floor;
// 经度
private Double latitude;
// 维度
private Double longitude;
// 店铺名称
private String name;
// 店铺地址
private String address;
// 店铺电话
private String phone;
// 店铺id
private String poiId;
}
不知道小伙伴有没有发现，我这里只是一个对象，没有一对多的关系哈，要的就是这样的效果。
但 json 文件里有个 coordinate 对象，而我实体对象不需要这个字段。那也没关系，一步步解析就完事了。
@RestController
public class ParseController {
private static final Logger LOGGER = LoggerFactory.getLogger(EasyExcelController.class);
@PostMapping(value = "/arrayObjectNestingParse",produces = "application/json;charset=UTF-8")
public ReturnT<String> arrayObjectNestingParse(@RequestParam(value = "jsonFile") MultipartFile jsonFile) {
if (jsonFile == null) {
return new ReturnT<>(ReturnT.BAD_REQUEST, "Params can not be null");
}
InputStream is = null;
BufferedReader br = null;
StringBuffer sb = new StringBuffer();
String str = null;
try {
is = jsonFile.getInputStream();
br = new BufferedReader(new InputStreamReader(is));
while ((str = br.readLine()) != null) {
sb.append(str);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
br.close();
} catch (IOException e) {
e.printStackTrace();
}
}
List<LocatorData> locatorDataList = new ArrayList<>();
JSONArray jsonArray = JSONArray.parseArray(sb.toString());
for (int i = 0; i < jsonArray.size(); i++) {
LocatorData locatorData = new LocatorData();
JSONObject jsonObject = jsonArray.getJSONObject(i);
String categories = jsonObject.getString("categories");
String coordinate = jsonObject.getString("coordinate");
JSONObject coordinateObj = JSONObject.parseObject(coordinate);
String address = coordinateObj.getString("address");
String area = coordinateObj.getString("area");
String areaId = coordinateObj.getString("area_id");
String city = coordinateObj.getString("city");
String cityCode = coordinateObj.getString("city_code");
String district = coordinateObj.getString("district");
String districtCode = coordinateObj.getString("district_code");
String floor = coordinateObj.getString("floor");
String latitude = coordinateObj.getString("latitude");
String longitude = coordinateObj.getString("longitude");
String province = coordinateObj.getString("province");
String provinceCode = coordinateObj.getString("province_code");
String name = jsonObject.getString("name");
String phone = jsonObject.getString("phone");
String poiId = jsonObject.getString("poi_id");
locatorData.setCategories(categories);
locatorData.setAddress(address);
locatorData.setArea(area);
locatorData.setAreaId(areaId);
locatorData.setProvince(province);
locatorData.setProvinceCode(provinceCode);
locatorData.setCity(city);
locatorData.setCityCode(cityCode);
locatorData.setDistrict(district);
locatorData.setDistrictCode(districtCode);
locatorData.setFloor(floor);
locatorData.setLatitude(Double.parseDouble(latitude));
locatorData.setLongitude(Double.parseDouble(longitude));
locatorData.setName(name);
locatorData.setPhone(phone);
locatorData.setPoiId(poiId);
locatorDataList.add(locatorData);
}
LOGGER.info("locatorDataList: " + JSON.toJSONString(locatorDataList));
return new ReturnT<>(ReturnT.SUCCESS, JSON.toJSONString(locatorDataList));
}
}
日志打印：
2020-01-07 00:39:30.284 [http-nio-8080-exec-3] INFO c.r.springbootdemo.controller.EasyExcelController-locatorDataList: [{"address":"王府井大街138号新东安广场3层328","area":"东安市场","areaId":"jk238eewf0k","categories":"[\"美食，小吃快餐\"]","city":"北京市","cityCode":"110100","district":"东城区","districtCode":"110101","floor":"3","latitude":39.91456,"longitude":116.41155,"name":"探鱼","phone":"010-65280328","poiId":"d7s8f6s6212","province":"北京市","provinceCode":"110000"},{"address":"丰台北路18号院恒泰广场F6楼","area":"恒泰广场","areaId":"ji8sgg3b32o","categories":"[\"美食，面包甜点\"]","city":"北京市","cityCode":"110100","district":"丰台区","districtCode":"110106","floor":"6","latitude":39.86608,"longitude":116.30516,"name":"好客来","phone":"010-65280221","poiId":"3g97sg8sd67","province":"北京市","provinceCode":"110000"}]
我们用工具转换一下看的更清晰一点：
[
{
"address": "王府井大街138号新东安广场3层328",
"area": "东安市场",
"areaId": "jk238eewf0k",
"categories": "["美食，小吃快餐"]",
"city": "北京市",
"cityCode": "110100",
"district": "东城区",
"districtCode": "110101",
"floor": "3",
"latitude": 39.91456,
"longitude": 116.41155,
"name": "探鱼",
"phone": "010-65280328",
"poiId": "d7s8f6s6212",
"province": "北京市",
"provinceCode": "110000"
},
{
"address": "丰台北路18号院恒泰广场F6楼",
"area": "恒泰广场",
"areaId": "ji8sgg3b32o",
"categories": "["美食，面包甜点"]",
"city": "北京市",
"cityCode": "110100",
"district": "丰台区",
"districtCode": "110106",
"floor": "6",
"latitude": 39.86608,
"longitude": 116.30516,
"name": "好客来",
"phone": "010-65280221",
"poiId": "3g97sg8sd67",
"province": "北京市",
"provinceCode": "110000"
}
]
json数组和List集合转换总结
//方法一,将json解析后赋给单独的元素
String jstr="{'json':'jsonvalue','bool':true,'int':1,'double':'20.5'}";
JSONObject json=JSONObject.fromObject(jstr);
boolean bool=json.getBoolean("bool");
int i=json.getInt("int");
double d=json.getDouble("double");
String value=json.getString("json");
System.out.println("bool="+String.valueOf(bool)+"\tjson="+value+"\tint="+i+"\tdouble="+d);
//方法二,json对象和bean对象之间相互转换
//假如你是有一个bean对象
class User{
private String name;
private String psw;
//封装getter/setter省略
}
//把一个json对象变成user
String u="{'name':'sail331x','psw':'123456789'}";
//用user对象接收json中的元素
User user=(User)JSONObject.toBean(JSONObject.fromObject(u),User.class);
//把一个user变成json对象：
JSONObject juser=JSONObject.fromObject(user);
//json字符串jstr
String jstr=juser.toString();
//方法三,json对象直接转list集合、list集合转json对象
//声明一个Person 实体类：
import java.util.Date;
public class Person {
String id;
int age;
String name;
Date birthday;
//get,set方法省略
}
//测试json数据转换
import java.util.Iterator;
import java.util.List;
import org.junit.Test;
import net.sf.json.JSONArray;
import net.sf.json.JsonConfig;
public class JsonToList {
public static void main(String[] args) {
String json="[{'name':'zhuangsan','age':18},{'name':'lisi','age':20}]";
JSONArray jsonarray = JSONArray.fromObject(json);
System.out.println(jsonarray);
List list = (List)JSONArray.toCollection(jsonarray, Person.class);
Iterator it = list.iterator();
while(it.hasNext()){
Person p = (Person)it.next();
System.out.println(p.getAge());
}
}
@Test
public void jsonToList1(){
String json="[{'name':'zhuangsan','age':18},{'name':'lisi','age':20}]";
JSONArray jsonarray = JSONArray.fromObject(json);
System.out.println(jsonarray);
List list = (List)JSONArray.toList(jsonarray, Person.class);
Iterator it = list.iterator();
while(it.hasNext()){
Person p = (Person)it.next();
System.out.println(p.getAge());
}
}
@Test
public void jsonToList2(){
String json="[{'name':'zhuangsan','age':20},{'name':'lisi','age':18}]";
JSONArray jsonarray = JSONArray.fromObject(json);
System.out.println(jsonarray);
System.out.println("------------");
List list = (List)JSONArray.toList(jsonarray, new Person(), new JsonConfig());
Iterator it = list.iterator();
while(it.hasNext()){
Person p = (Person)it.next();
System.out.println(p.getAge());
}
}
}
//将list对象转为JSON字符串数组：
import java.util.LinkedList;
import java.util.List;
import net.sf.json.JSONArray;
public class ListToJson {
public static void main(String[] args) {
List list = new LinkedList();
for(int i=0;i<3;i++){
Person p = new Person();
p.setAge(i);
p.setName("name"+i);
list.add(p);
}
JSONArray jsonarray = JSONArray.fromObject(list);
System.out.println(jsonarray);
}
}
以上为个人经验，希望能给大家一个参考，也希望大家多多支持。
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