相当于这个Json的GraphQL模式？

Question

I'm newbie to GraphQL, and was wondering if someone could help me figure out what is the equivalent of below JSON into GraphQL schema:

[
 {
   "id": "1",
   "name": "A",
   "fldDef": [
    {
      "name": "f1",
      "type": "str",
      "opt": false
    },
    {
      "name": "f2",
      "type": "bool"
    }]
 },
 {
    "id": "2",
    "name": "B",
    "fldDef": [
     {
       "name": "f3",
       "type": "str",
       "opt": true
     },
     {
       "name": "f4",
       "type": "str",
       "opt": true
     }]
  }
]

So far I managed to map above response to below object:

  public class FldDef {

     private String name, type;
     private boolean opt;
     // getters & setters
 } 

 public class Product {

    private String id, name;
    private Map<String, FldDef> fldDef;

   // getters & setters

 }

Then my schema looks like below, but the problem I'm having is as a part of Product object, I've a Map which I would like to get the schema right for it, but I'm having difficulty getting the schema right!

type FldDef { 
   name: String!
   type: String!
   opt: Boolean!
} 

type Product {
   id: String!
   name: String!
   fldDef: FldDef! // now here I don't know what is the syntax for representing MAP, do you know how to achieve this?
 }

I get below exception:

Causedby:com.coxautodev.graphql.tools.TypeClassMatcher$RawClassRequiredForGraphQLMappingException: Type java.util.Map<java.lang.String, com.grapql.research.domain.FldDef> cannot be mapped to a GraphQL type! Since GraphQL-Java deals with erased types at runtime, only non-parameterized classes can represent a GraphQL type. This allows for reverse-lookup by java class in interfaces and union types.

Note: I'm working with Java eco-system (graphql-java)

Answer 1

giving you a schema from your JSON is not really possible because a schema contains much more information than just simply the shape of your data. I think the best for you would be to learn the basics of GraphQL, designing simple schemas is then very easy and fun! Maybe start with the learning section on graphql.org . They have a section about the schema . Basically you build your schema from scalars (aka primitives) and object types. All types can additionally be wrapped in the non-nullable type and/or of the list type. GraphQL was designed for clients. The easiest way of understanding GraphQL is making some queries against an existing API. Launchpad has a lot of examples that you can use (and modify when you know some JavaScript).

Answer 2

You can try some changes as below:

Schema definition:

type FldDef {
   name: String!
   type: String!
   opt: Boolean!
}

type Product {
   id: String!
   name: String!
   fldDef: [FldDef]! // make it as Collection of FldDef
 }

Java Class:

public class FldDef {

    private String name;
    private String type;
    private boolean opt;
    // getters & setters
}

public class Product {

    private String id;
    private String name;
    private List<FldDef> fldDef; // Change to List of FldDef
    // getters & setters
}

Hope it can help.