What’s Changed

Highlights

• Upgrade to graphql-java:17.3, which has many improvements.
• A WebClient based GraphQL client implementation.
• Refactored existing GraphQL client implementation for better ergonomics.

Full list of changes

• Add ParameterNamesModule and Jdk8Module to the GraphQLResponse object mapper. (#670) @srinivasankavitha
• Added createWithWebClient factory method that takes header consumer (#669) @paulbakker
• refactored dgs client, and new Webclient based client. (#658) @paulbakker
• Update contributing doc (#662) @hantsy
• Upgrade to graphql-java 17.0 (#518) @berngp
• Adopt kotlinter-gradle instead of org.jlleitschuh.gradle:ktlint-gradle (#393) @berngp

Migrating to the new GraphQLClient

In this release we deprecated the DefaultGraphQLClient class and the existing executeQuery methods on the GraphQLClient and MonoGraphQLClient interfaces.
The deprecated methods required a RequestExecutor to be passed in that takes care of the actual HTTP request. Requiring a RequestExecutor makes it possible to plug-in any HTTP client, but requires quite a bit of plumbing.

The deprecated class/methods are replaced by the following:

• A brand new WebClientGraphQLClient. If you don't have a strong opinion about what HTTP client to use, this is the easiest way to use the client. The user just provides a WebClient instance, and the framework takes care of the rest. This should be the preferred method for most users!
• If you do have a strong opinion about what HTTP client to use, you can continue to use the RequestExecutor approach using the new CustomGraphQLClient or CustomMonoGraphQLClient classes. The RequestExecutor is now defined as a constructor argument instead of at each execute* method for better ergonomics. You can use your existing RequestExecutor implementation however!

Below are two examples of how to migrate an existing usage of DefaultGraphQLClient to either of the new approaches.

A DefaultGraphQLClient that we'll migrate.

RestTemplate restTemplate = new RestTemplate();
String url = "http://localhost:8080/graphql";
DefaultGraphQLClient client = new DefaultGraphQLClient(url);

RequestExecutor requestExecutor = (url, headers, body) -> {
    HttpHeaders httpHeaders = new HttpHeaders();
    headers.forEach(httpHeaders::addAll);
    ResponseEntity<String> exchange = restTemplate.exchange(url, HttpMethod.POST, new HttpEntity<>(body, httpHeaders),String.class);
    return new HttpResponse(exchange.getStatusCodeValue(), exchange.getBody());
};

client.executeQuery(query, variables, requestExecutor);

Using WebClient

WebClient webClient = WebClient.create("http://localhost:8080/graphql");
WebClientGraphQLClient client = MonoGraphQLClient.createWithWebClient(webClient);
        
client.reactiveExecuteQuery(query);

Optionally, you can provide a Consumer<HttpHeader> to the WebClientGraphQLClient to provide additional headers.

WebClient webClient = WebClient.create("http://localhost:8080/graphql");
WebClientGraphQLClient client = MonoGraphQLClient.createWithWebClient(WebClient.create("http://localhost:$port/graphql" ,  headers ->
  headers.add("myheader", "test")
);
        
client.reactiveExecuteQuery(query);

Using CustomGraphQLClient

RequestExecutor requestExecutor = (url, headers, body) -> {
    HttpHeaders httpHeaders = new HttpHeaders();
    headers.forEach(httpHeaders::addAll);
    ResponseEntity<String> exchange = restTemplate.exchange(url, HttpMethod.POST, new HttpEntity<>(body, httpHeaders),String.class);
    return new HttpResponse(exchange.getStatusCodeValue(), exchange.getBody());
};

CustomGraphQLClient client = GraphQLClient.createCustom(url, requestExecutor);
client.executeQuery(query); //the RequestExecutor was already passed in to the constructor

Updated docs for the new client.