Question

I have this type of json from api:

[
    {
        "id": "12",
        "name": "elo2",
        "status": "ok",
        "vulumes": [
            {
                "id": 17592,
                "name": "vol1",
                "status": "ok"
            }
        ]
    },
    {
        "id": "13",
        "name": "elo",
        "status": "ok",
        "vulumes": [
            {
                "id": "17596",
                "name": "vol2",
                "status": "ok"
            }
        ]
    }
]

ID 12 and 13 its shelf, volumes is a part of shelf with id 17592 and 17596

I cannot to parse it with json, i trying to use gson or json, but i can’t understand how to get sime block, for e.g. block with id 12 for parse info about shelf and existing volumes at this shelf.

Can you help me? In other apis i can see named objects vith k/v, but there is nothing.

Answer 1

With Gson, here’s one simple approach you could take. This demonstrates a Java data structure that matches the JSON example, along with how to deserialize and serialize it using Gson.

public class Foo
{
  public static void main(String[] args) throws Exception
  {
    Gson gson = new Gson();
    Type thingsType = new TypeToken<List<Thing>>() {}.getType();
    List<Thing> things = gson.fromJson(new FileReader("input.json"), thingsType);
    System.out.println(gson.toJson(things));
  }
}

class Thing
{
  String id;
  String name;
  String status;
  List<Vulume> vulumes;
}

class Vulume
{
  String id;
  String name;
  String status;
}

Since the attributes of the two object types are almost identical, then maybe the intention was that there be only one object type, with a reference to a collection of objects of the same type. Here’s what that would look like.

public class Foo
{
  public static void main(String[] args) throws Exception
  {
    Gson gson = new Gson();
    Type thingsType = new TypeToken<List<Vulume>>() {}.getType();
    List<Vulume> things = gson.fromJson(new FileReader("input.json"), thingsType);
    System.out.println(gson.toJson(things));
  }
}

class Vulume
{
  String id;
  String name;
  String status;
  List<Vulume> vulumes;
}