org.springframework.graphql.execution.SubscriptionExceptionResolver Maven / Gradle / Ivy
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/*
* Copyright 2002-2022 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.graphql.execution;
import java.util.List;
import java.util.function.Function;
import graphql.GraphQLError;
import reactor.core.publisher.Mono;
/**
* Contract for a component that is invoked when a GraphQL subscription
* {@link org.reactivestreams.Publisher} ends with an error.
*
* Resolver implementations can extend the convenience base class
* {@link SubscriptionExceptionResolverAdapter} and override one of its methods
* {@link SubscriptionExceptionResolverAdapter#resolveToSingleError resolveToSingleError} or
* {@link SubscriptionExceptionResolverAdapter#resolveToMultipleErrors resolveToMultipleErrors}
* that resolve the exception synchronously.
*
*
Resolved errors are wrapped in a {@link SubscriptionPublisherException}
* and propagated further to the underlying transport which access the errors
* and prepare a final error message to send to the client.
*
* @author Mykyta Ivchenko
* @author Rossen Stoyanchev
* @since 1.0.1
* @see SubscriptionExceptionResolverAdapter
*/
@FunctionalInterface
public interface SubscriptionExceptionResolver {
/**
* Resolve the given exception to a list of {@link GraphQLError}'s to be
* sent in an error message to the client.
* @param exception the exception from the Publisher
* @return a {@code Mono} with the GraphQL errors to send to the client;
* if the {@code Mono} completes with an empty List, the exception is resolved
* without any errors to send; if the {@code Mono} completes empty, without
* emitting a List, the exception remains unresolved, and that allows other
* resolvers to resolve it.
*/
Mono> resolveException(Throwable exception);
/**
* Factory method to create a {@link SubscriptionExceptionResolver} to
* resolve an exception to a single GraphQL error. Effectively, a shortcut
* for creating {@link SubscriptionExceptionResolverAdapter} and overriding
* its {@code resolveToSingleError} method.
* @param resolver the resolver function to map the exception
* @return the created instance
*/
static SubscriptionExceptionResolverAdapter forSingleError(Function resolver) {
return new SubscriptionExceptionResolverAdapter() {
@Override
protected GraphQLError resolveToSingleError(Throwable ex) {
return resolver.apply(ex);
}
};
}
}