为处理物理建筑的应用程序构建模型。
理想情况下，我们想要这样的事情：
城市有多个办公室，有多个房间，有房产。
我们使用jackson来解析从API数据源收到的JSON有效负载，最终看起来与我见过的示例有点不同。
我们获得的格式是：
{
"CityName1":
{ "OfficeName1":
[
{"name": RoomName1, "RoomProperty2": RoomValue1},
{"name": RoomName2, "RoomProperty2": RoomValue2}
]
},
{ "OfficeName2": [{...}]},
{ "OfficeNameX" : [{...}] },
"CityName2": {...},
"CityNameN": {...}}
Java类：
public class City {
private Map<String, Object> additionalProperties = new HashMap<String, Object();
private List<Office> _offices = new ArrayList<Office>();
@JsonAnyGetter
public Map<String, Object> getAdditionalProperties() {
return this.additionalProperties;
}
@JsonAnySetter
public void setAdditionalProperty(String name, Object value)
throws IOException {
_cityName = name;
String officeJson = _mapper.writeValueAsString(value);
StringBuilder sb = new StringBuilder(officeJson);
_offices.add(_mapper.readValue(officeJson, Office.class));
this.additionalProperties.put(name, value);
}
}
public class Office {
private String _officeName;
private static final ObjectMapper _mapper = new ObjectMapper();
private Map<String, Object> additionalProperties = new HashMap<String, Object>();
private List<Room> _rooms = new ArrayList<Room>();
@JsonAnyGetter
public Map<String, Object> getAdditionalProperties() {
return this.additionalProperties;
}
@JsonAnySetter
public void setAdditionalProperty(String name, Object value)
throws IOException {
_officeName = name;
String roomJson = _mapper.writeValueAsString(value);
Room[] rooms = _mapper.readValue(roomJson, Room[].class);
_rooms.addAll(Arrays.asList(rooms));
this.additionalProperties.put(name, value);
}
public List<Room> getRooms() {
return _rooms;
}
public void setRooms(List<Room> rooms) {
_rooms = rooms;
}
}
public class Room {
private static final String NAME = "name";
private static final String PROP_2 = "RoomProperty2";
@JsonProperty(PROP_2)
private String _propertyTwo;
@JsonProperty(NAME)
private String name;
@JsonProperty(PROP_2)
public String getPropertyTwo() {
return _propertyTwo;
}
@JsonProperty(PROP_2)
public void setPropertyTwo(String propTwo) {
_propertyTwo = propTwo;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
那么我如何用杰克逊解析这个呢？目前，我使用@JsonAnySetter获取名称，并将其保存为城市或办公室名称，然后将发送到JsonAnySetter的值发送到相应的嵌套类。真正的问题在于获取城市办事处的名单。使用mapper.readvalues（String，Office.class）时，我只返回每个城市的最后一个办公室的迭代器。有什么想法吗？
很抱歉，如果这看起来令人困惑！很想回答我创造的任何问题。
感谢您的帮助！
答案 0 :(得分：3)
我认为最好的解决方案是在这里编写自己的deserialiser，因为您的JSON文档并没有真正映射到您想要的类结构。
下面的解决方案将每个城市作为Map<String, List<Room>>，将城市集合作为Map<String, City>，然后在解串器中创建City和Office个对象。< / p>
Room.java和你的一样，其余的就是：
<强> Cities.java ：
@JsonDeserialize(using=CitiesDeserializer.class)
public class Cities implements Iterable<City> {
private final List<City> cities;
public Cities(final List<City> cities) {
this.cities = cities;
}
public Cities() {
this.cities = new ArrayList<>();
}
public List<City> getCities() {
return cities;
}
@Override
public Iterator<City> iterator() {
return cities.iterator();
}
}
<强> CitiesDeserialiser.java ：
public class CitiesDeserializer extends JsonDeserializer<Cities> {
private static final TypeReference<Map<String, City>> TYPE_REFERENCE = new TypeReference<Map<String, City>>() {};
@Override
public Cities deserialize(final JsonParser jp, final DeserializationContext ctxt) throws IOException {
final Map<String, City> map = jp.readValueAs(TYPE_REFERENCE);
List<City> cities = new ArrayList<>();
for(Map.Entry<String, City> entry : map.entrySet()) {
City city = entry.getValue();
city.setName(entry.getKey());
cities.add(city);
}
return new Cities(cities);
}
}
<强> City.java ：
@JsonDeserialize(using=CityDeserialzer.class)
public class City {
private String name;
private List<Office> offices;
// Setters and getters
}
<强> CityDeserializer.java ：
public class CityDeserialzer extends JsonDeserializer<City> {
private static final TypeReference<Map<String, List<Room>>> TYPE_REFERENCE = new TypeReference<Map<String, List<Room>>>() {};
@Override
public City deserialize(final JsonParser jp, final DeserializationContext ctxt) throws IOException {
final Map<String, List<Room>> map = jp.readValueAs(TYPE_REFERENCE);
List<Office> offices = new ArrayList<>();
for(Map.Entry<String, List<Room>> entry : map.entrySet()) {
Office office = new Office();
office.setName(entry.getKey());
office.setRooms(entry.getValue());
offices.add(office);
}
City city = new City();
city.setOffices(offices);
return city;
}
}
<强> Office.java ：
public class Office {
private String name;
private List<Room> rooms;
// Setters and getters
}
这是一个测试，表明它有效：
JSON：
{
"CityName1": {
"OfficeName1": [ {
"name": "RoomName1",
"RoomProperty2": "RoomValue1"
}, {
"name": "RoomName2",
"RoomProperty2": "RoomValue2"
} ],
"OfficeName2": [ {
"name": "RoomName3",
"RoomProperty2": "RoomValue3"
}, {
"name": "RoomName4",
"RoomProperty2": "RoomValue4"
} ]
},
"CityName2": {
"OfficeName3": [ {
"name": "RoomName5",
"RoomProperty2": "RoomValue5"
}, {
"name": "RoomName6",
"RoomProperty2": "RoomValue6"
} ],
"OfficeName4": [ {
"name": "RoomName7",
"RoomProperty2": "RoomValue7"
}, {
"name": "RoomName8",
"RoomProperty2": "RoomValue8"
} ]
}
}
<强> Test.java ：
public class Test {
public static void main(String[] args) {
String json = ...
ObjectMapper mapper = new ObjectMapper();
Cities cities = mapper.readValue(json, Cities.class);
for(City city : cities) {
System.out.println(city.getName());
for(Office office : city.getOffices()) {
System.out.println("\t" + office.getName());
for(Room room : office.getRooms()) {
System.out.println("\t\t" + room.getName());
System.out.println("\t\t\t" + room.getPropertyTwo());
}
}
}
}
}
输出：
CityName1
OfficeName1
RoomName1
RoomValue1
RoomName2
RoomValue2
OfficeName2
RoomName3
RoomValue3
RoomName4
RoomValue4
CityName2
OfficeName3
RoomName5
RoomValue5
RoomName6
RoomValue6
OfficeName4
RoomName7
RoomValue7
RoomName8
RoomValue8