Package org.springframework.graphql.execution

Interface DataFetcherExceptionResolver

All Known Implementing Classes:

DataFetcherExceptionResolverAdapter, ReactiveSecurityDataFetcherExceptionResolver, SecurityDataFetcherExceptionResolver

public interface DataFetcherExceptionResolver

Contract to resolve exceptions from DataFetchers. Implementations are typically declared as beans in Spring configuration and are invoked sequentially until one emits a List of GraphQLErrors.

Most resolver implementations can extend DataFetcherExceptionResolverAdapter and override one of its resolveToSingleError or resolveToMultipleErrors methods that resolve the exception synchronously.

Resolver implementations can use ErrorType to classify errors using one of several common categories.

Since:

1.0.0

Author:

Rossen Stoyanchev

See Also:

• ErrorType
• DataFetcherExceptionResolverAdapter
• ExceptionResolversExceptionHandler

Method Summary

Modifier and Type	Method	Description
static DataFetcherExceptionHandler	createExceptionHandler(List<DataFetcherExceptionResolver> resolvers)	Factory method to create a DataFetcherExceptionResolver from a list of resolvers.
static DataFetcherExceptionResolverAdapter	forSingleError(BiFunction<Throwable,DataFetchingEnvironment,GraphQLError> resolver)	Factory method to create a DataFetcherExceptionResolver to resolve an exception to a single GraphQL error.
reactor.core.publisher.Mono<List<GraphQLError>>	resolveException(Throwable exception, DataFetchingEnvironment environment)	Resolve the given exception and return the error(s) to add to the response.

Method Details

resolveException

reactor.core.publisher.Mono<List<GraphQLError>> resolveException(Throwable exception,
 DataFetchingEnvironment environment)

Resolve the given exception and return the error(s) to add to the response.

Implementations can use GraphqlErrorBuilder.newError(DataFetchingEnvironment) to create an error with the coordinates of the target field, and use ErrorType to specify a category for the error.

Parameters:

exception - the exception to resolve

environment - the environment for the invoked DataFetcher

Returns:

a Mono with errors to add to the GraphQL response; if the Mono completes with an empty List, the exception is resolved without any errors added to the response; if the Mono completes empty, without emitting a List, the exception remains unresolved and that allows other resolvers to resolve it.

forSingleError

static DataFetcherExceptionResolverAdapter forSingleError(BiFunction<Throwable,DataFetchingEnvironment,GraphQLError> resolver)

Factory method to create a DataFetcherExceptionResolver to resolve an exception to a single GraphQL error. Effectively, a shortcut for creating DataFetcherExceptionResolverAdapter and overriding its resolveToSingleError method.

Parameters:

resolver - the resolver function to use

Returns:

the created instance

Since:

1.0.1

createExceptionHandler

static DataFetcherExceptionHandler createExceptionHandler(List<DataFetcherExceptionResolver> resolvers)

Factory method to create a DataFetcherExceptionResolver from a list of resolvers. Spring for GraphQL uses this method to set GraphQL.Builder.defaultDataFetcherExceptionHandler(DataFetcherExceptionHandler) from resolvers found in Spring configuration, and that default handler is used in turn to create each ExecutionStrategy. Applications may also find this factory method useful when creating a custom ExecutionStrategy.

Resolvers are invoked in turn until one resolves the exception by emitting a (possibly empty) GraphQLError list. If the exception remains unresolved, the handler creates a GraphQLError with ErrorType.INTERNAL_ERROR and a short message with the execution id.

Parameters:

resolvers - the list of resolvers to use

Returns:

the created DataFetcherExceptionHandler instance

Since:

1.1.1