Difference between Datafetchers and Resolvers

Question

I am planning to implement Graphql in my spring boot application. I Googled many sites for Graphql server setup in Java and came across two ways of doing it .

One is implementing GraphQlResolver like below

 public class MyResolver implements GraphQLResolver<ModelX>

and another one is by Implementing Datafetcher Reference: https://www.graphql-java.com

@Component
public class MyDataFetcher implements DataFetcher<ModelX> {


@Override
public ModelX get(DataFetchingEnvironment environment) {
    // TODO Auto-generated method stub

}

}

Please provide some information on differences in both the approaches and best among them

Answer 1

DataFetcher is from graphql-java library , the only GraphQL Java implementation that I known in Java world so far.

GraphQLResolver is from another library called graphql-java-tools which is built on top of graphql-java . You can think that it provides a way which allow you to build a GraphQL server in a more high level way or a way that you may find more convenient. At the end , GraphQLResolver will somehow invoke DataFetcher#get() for resolving the value for a field.

An similar analogy in Spring is that graphql-java like Servlet while graphql-java-tools like SpringMVC.