1 /*
2 * Copyright 2002-2015 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package org.springframework.messaging.handler.invocation;
18
19 import org.springframework.core.MethodParameter;
20 import org.springframework.messaging.Message;
21
22 /**
23 * Strategy interface for resolving method parameters into argument values
24 * in the context of a given {@link Message}.
25 *
26 * @author Rossen Stoyanchev
27 * @since 4.0
28 */
29 public interface HandlerMethodArgumentResolver {
30
31 /**
32 * Whether the given {@linkplain MethodParameter method parameter} is
33 * supported by this resolver.
34 * @param parameter the method parameter to check
35 * @return {@code true} if this resolver supports the supplied parameter;
36 * {@code false} otherwise
37 */
38 boolean supportsParameter(MethodParameter parameter);
39
40 /**
41 * Resolves a method parameter into an argument value from a given message.
42 * @param parameter the method parameter to resolve.
43 * This parameter must have previously been passed to
44 * {@link #supportsParameter(org.springframework.core.MethodParameter)}
45 * which must have returned {@code true}.
46 * @param message the currently processed message
47 * @return the resolved argument value, or {@code null}
48 * @throws Exception in case of errors with the preparation of argument values
49 */
50 Object resolveArgument(MethodParameter parameter, Message<?> message) throws Exception;
51
52 }