Jackson deserialization list class

Question

There is a json with a sheet as a nested class:

{
 "name": "test",
 "phoneList": {
 "phone": [
 {
 "number": 32323232,
 "code": 555
 },
 {
 "number": 4343423432,
 "code": 555
 }
 ]
 }
}

The following DTO class is suitable for this json:

class Response {
 String name;
 PhoneList phoneList;
 static class PhoneList {
 List<Phone> phone = new ArrayList<>();
 static class Phone {
 String number;
 Integer code;
 }
 }
}

Is it possible somehow not to create a PhoneList class, but to create a sheet directly?

class Response {
 String name;
 List<Phone> phoneList = new ArrayList<>();
 static class Phone {
 String number;
 Integer code;
 }
}

• Maurice Perry: Consider declaring your internal classes as static.

Answer 1

You may add below method and it is gonna work like a charm (of course if you make those DTOs proper Jacson pojos (i.e. default constructor + setters/getter)

@JsonProperty("phoneList")
private void mapPhones(Map<String, List<Phone>> phoneList) {
 this.phoneList = phoneList.get("phone");
}

• wuttke: Thanks! A good option, but I use an immutable class as a dto (I forgot to specify it).
• Michał Marcinkowski: then you may use it in constructor, the syntax exactly the same public Response (@JsonProperty("name) name, @JsonProperty("phoneList") Map<String, List<Phone>> phoneList) { this.name = name; this.phoneList = phoneList.get("phone") }
• Michał Marcinkowski: @wuttke if you find my answer helpful please mark is as accepted.

Answer 2

Yes, you can create that directly. Take a look at below code :

1. Response Class

class Response {
 String name;
 List<Phone> phoneList = new ArrayList<>();
 public Response() {
 }
 public String getName() {
 return name;
 }
 public void setName(String name) {
 this.name = name;
 }
 public List<Phone> getPhoneList() {
 return phoneList;
 }
 public void setPhoneList(List<Phone> phoneList) {
 this.phoneList = phoneList;
 }
 @Override
 public String toString() {
 return "Response{" + "name=" + name + ", phoneList=" + phoneList + '}';
 }
 class Phone {
 String number;
 Integer code;
 public String getNumber() {
 return number;
 }
 public void setNumber(String number) {
 this.number = number;
 }
 public Phone() {
 }
 public Integer getCode() {
 return code;
 }
 public void setCode(Integer code) {
 this.code = code;
 }
 @Override
 public String toString() {
 return "Phone{" + "number=" + number + ", code=" + code + '}';
 }
 }
}

2. Main Class

public static void main(String[] args) throws JsonProcessingException {
 Response response = new Response();
 response.setName("test");
 Response.Phone phone = response.new Phone();
 phone.setNumber("32323232");
 phone.setCode(555);
 response.phoneList.add(phone);
 phone = response.new Phone();
 phone.setNumber("4343423432");
 phone.setCode(555);
 response.phoneList.add(phone);
 System.out.println(response.toString());
 ObjectMapper mapper = new ObjectMapper();
 mapper.enable(SerializationFeature.INDENT_OUTPUT);
 System.out.println(mapper.writeValueAsString(response));
}