001/* 002 * Copyright 2002-2015 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.messaging.handler.invocation; 018 019import org.springframework.core.MethodParameter; 020import org.springframework.lang.Nullable; 021import org.springframework.messaging.Message; 022 023/** 024 * Strategy interface for resolving method parameters into argument values 025 * in the context of a given {@link Message}. 026 * 027 * @author Rossen Stoyanchev 028 * @since 4.0 029 */ 030public interface HandlerMethodArgumentResolver { 031 032 /** 033 * Whether the given {@linkplain MethodParameter method parameter} is 034 * supported by this resolver. 035 * @param parameter the method parameter to check 036 * @return {@code true} if this resolver supports the supplied parameter; 037 * {@code false} otherwise 038 */ 039 boolean supportsParameter(MethodParameter parameter); 040 041 /** 042 * Resolves a method parameter into an argument value from a given message. 043 * @param parameter the method parameter to resolve. 044 * This parameter must have previously been passed to 045 * {@link #supportsParameter(org.springframework.core.MethodParameter)} 046 * which must have returned {@code true}. 047 * @param message the currently processed message 048 * @return the resolved argument value, or {@code null} 049 * @throws Exception in case of errors with the preparation of argument values 050 */ 051 @Nullable 052 Object resolveArgument(MethodParameter parameter, Message<?> message) throws Exception; 053 054}