org.springframework.web.reactive.HandlerAdapter Maven / Gradle / Ivy
/*
* Copyright 2002-2016 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.web.reactive;
import java.util.function.Function;
import reactor.core.publisher.Mono;
import org.springframework.web.server.ServerWebExchange;
/**
* Contract that decouples the {@link DispatcherHandler} from the details of
* invoking a handler and makes it possible to support any handler type.
*
* @author Rossen Stoyanchev
* @author Sebastien Deleuze
* @since 5.0
*/
public interface HandlerAdapter {
/**
* Whether this {@code HandlerAdapter} supports the given {@code handler}.
* @param handler the handler object to check
* @return whether the handler is supported
*/
boolean supports(Object handler);
/**
* Handle the request with the given handler.
* Implementations are encouraged to handle exceptions resulting from the
* invocation of a handler in order and if necessary to return an alternate
* result that represents an error response.
*
Furthermore since an async {@code HandlerResult} may produce an error
* later during result handling implementations are also encouraged to
* {@link HandlerResult#setExceptionHandler(Function) set an exception
* handler} on the {@code HandlerResult} so that may also be applied later
* after result handling.
* @param exchange current server exchange
* @param handler the selected handler which must have been previously
* checked via {@link #supports(Object)}
* @return {@link Mono} that emits a single {@code HandlerResult} or none if
* the request has been fully handled and doesn't require further handling.
*/
Mono handle(ServerWebExchange exchange, Object handler);
}