json如何解析混合数组对象到实体类的list集合里去
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。