/*
* Copyright 2008 biaoping.yin
*
* 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
*
* http://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.frameworkset.web.servlet.support;
import org.frameworkset.util.MethodParameter;
import org.frameworkset.web.servlet.mvc.NativeWebRequest;
/**
* <p>Title: WebArgumentResolver.java</p>
* <p>Description: SPI for resolving custom arguments for a specific handler method parameter.
* Typically implemented to detect sppecial parameter types, resolving
* well-known argument values for them.
*
* <p>A typical implementation could look like as follows:
*
* <pre class="code">
* public class MySpecialArgumentResolver implements ArgumentResolver {
*
* public Object resolveArgument(MethodParameter methodParameter, NativeWebRequest webRequest) {
* if (methodParameter.getParameterType().equals(MySpecialArg.class)) {
* return new MySpecialArg("myValue");
* }
* return UNRESOLVED;
* }
* }</pre>
*</p>
* <p>bboss workgroup</p>
* <p>Copyright (c) 2008</p>
* @Date 2010-10-24
* @author biaoping.yin
* @version 1.0
*/
public interface WebArgumentResolver {
/**
* Marker to be returned when the resolver does not know how to
* handle the given method parameter.
*/
Object UNRESOLVED = new Object();
/**
* Resolve an argument for the given handler method parameter within the given web request.
* @param methodParameter the handler method parameter to resolve
* @param webRequest the current web request, allowing access to the native request as well
* @return the argument value, or <code>UNRESOLVED</code> if not resolvable
* @throws Exception in case of resolution failure
*/
Object resolveArgument(MethodParameter methodParameter, NativeWebRequest webRequest) throws Exception;
}