README.md

GraphQL Spring Webclient

Reactive GraphQL client for consuming GraphQL APIs from a Spring Boot application. Provides OAuth2 authorization through configuration.

Getting started

Add the starter to your project.

When using Maven:

<dependency>
  <groupId>com.graphql-java-kickstart</groupId>
  <artifactId>graphql-webclient-spring-boot-starter</artifactId>
  <version>2.0.0</version>
</dependency>

When using gradle:

implementation "com.graphql-java-kickstart:graphql-webclient-spring-boot-starter:2.0.0"

Configure at least the URL of the GraphQL API to consume:

graphql:
  client:
    url: https://graphql.github.com/graphql

The starter creates a Spring bean of type GraphQLWebClient that you can use in your classes to send queries. A simplified example might look like this:

@Component
class MyClass {
  
  private final GraphQLWebClient graphQLWebClient;
  
  MyClass(GraphQLWebClient graphQLWebClient) {
    this.graphQLWebClient = graphQLWebClient;
  }
  
  String helloWorld() {
    GraphQLRequest request = GraphQLRequest.builder().query("query { hello }").build();
    GraphQLResponse response = graphQLWebClient.post(request).block();
    return response.get("hello", String.class);
  }
}

Using latest Snapshots

You can use the latest Snapshots by configuring the Snapshot repository, see https://www.graphql-java-kickstart.com/servlet/#using-the-latest-development-build.

Configuration

The following tables list the configurable properties of the GraphQL Spring Webclient and their default values. These properties are configured with the prefix graphql.client, e.g. the property listed in the table as url should be defined as graphql.client.url in your Spring Boot configuration files.

Property	Description
url	Full URL of the GraphQL API to connect to, e.g. https://graphql.github.com/graphql
oauth2.client-id	OAuth2 client id
oauth2.client-secret	OAuth2 client secret
oauth2.token-uri	Token URI of the identity provider
oauth2.authorization-grant-type	By default the grant type client_credentials is used
retry.strategy	The retry strategy to auto configure for the WebClient (possible values are none, backoff, fixed_delay, indefinitely, max and max_in_row). Default is none.
retry.backoff.max-attempts	The maximum number of retry attempts to allow (only used when retry.strategy = backoff).
retry.backoff.min-backoff	The minimum duration for the first backoff (only used when retry.strategy = backoff). Default is 0.
retry.backoff.max-backoff	The maximum duration for the exponential backoffs (only used when retry.strategy = backoff). Default is Duration.ofMillis(Long.MAX_VALUE).
retry.fixed-delay.max-attempts	The maximum number of retry attempts to allow (only used when retry.strategy = fixed_delay).
retry.fixed-delay.delay	The duration of the fixed delays between attempts (only used when retry.strategy = fixed_delay).
retry.max.max-attempts	The maximum number of retry attempts to allow (only used when retry.strategy = max).
retry.max-in-row.max-attempts	The maximum number of retry attempts to allow in a row (only used when retry.strategy = max_in_row).

Max in memory size

In case you need to work with large responses you might run into the following error:

Exceeded limit on max bytes to buffer : 262144

In that case starting with version 0.1.2 you can use the default Spring Boot configuration property to configure the max in memory size to use:

spring.codec.max-in-memory-size=10MB