001/* 002 * Copyright 2002-2018 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.web.reactive.result.method; 018 019import reactor.core.publisher.Mono; 020 021import org.springframework.core.MethodParameter; 022import org.springframework.lang.Nullable; 023import org.springframework.web.reactive.BindingContext; 024import org.springframework.web.server.ServerWebExchange; 025 026/** 027 * An extension of {@link HandlerMethodArgumentResolver} for implementations 028 * that are synchronous in nature and do not block to resolve values. 029 * 030 * @author Rossen Stoyanchev 031 * @since 5.0 032 */ 033public interface SyncHandlerMethodArgumentResolver extends HandlerMethodArgumentResolver { 034 035 /** 036 * {@inheritDoc} 037 * <p>By default this simply delegates to {@link #resolveArgumentValue} for 038 * synchronous resolution. 039 */ 040 @Override 041 default Mono<Object> resolveArgument( 042 MethodParameter parameter, BindingContext bindingContext, ServerWebExchange exchange) { 043 044 return Mono.justOrEmpty(resolveArgumentValue(parameter, bindingContext, exchange)); 045 } 046 047 /** 048 * Resolve the value for the method parameter synchronously. 049 * @param parameter the method parameter 050 * @param bindingContext the binding context to use 051 * @param exchange the current exchange 052 * @return the resolved value, if any 053 */ 054 @Nullable 055 Object resolveArgumentValue( 056 MethodParameter parameter, BindingContext bindingContext, ServerWebExchange exchange); 057 058}