org.springframework.messaging.handler.invocation.HandlerMethodArgumentResolverComposite Maven / Gradle / Ivy
/*
* Copyright 2002-2018 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
*
* 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.springframework.messaging.handler.invocation;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.springframework.core.MethodParameter;
import org.springframework.lang.Nullable;
import org.springframework.messaging.Message;
/**
* Resolves method parameters by delegating to a list of registered
* {@link HandlerMethodArgumentResolver}. Previously resolved method parameters are cached
* for faster lookups.
*
* @author Rossen Stoyanchev
* @author Juergen Hoeller
* @since 4.0
*/
public class HandlerMethodArgumentResolverComposite implements HandlerMethodArgumentResolver {
private final List argumentResolvers = new LinkedList<>();
private final Map argumentResolverCache =
new ConcurrentHashMap<>(256);
/**
* Add the given {@link HandlerMethodArgumentResolver}.
*/
public HandlerMethodArgumentResolverComposite addResolver(HandlerMethodArgumentResolver argumentResolver) {
this.argumentResolvers.add(argumentResolver);
return this;
}
/**
* Add the given {@link HandlerMethodArgumentResolver HandlerMethodArgumentResolvers}.
* @since 4.3
*/
public HandlerMethodArgumentResolverComposite addResolvers(@Nullable HandlerMethodArgumentResolver... resolvers) {
if (resolvers != null) {
Collections.addAll(this.argumentResolvers, resolvers);
}
return this;
}
/**
* Add the given {@link HandlerMethodArgumentResolver HandlerMethodArgumentResolvers}.
*/
public HandlerMethodArgumentResolverComposite addResolvers(
@Nullable List argumentResolvers) {
if (argumentResolvers != null) {
this.argumentResolvers.addAll(argumentResolvers);
}
return this;
}
/**
* Return a read-only list with the contained resolvers, or an empty list.
*/
public List getResolvers() {
return Collections.unmodifiableList(this.argumentResolvers);
}
/**
* Clear the list of configured resolvers.
*/
public void clear() {
this.argumentResolvers.clear();
}
/**
* Whether the given {@linkplain MethodParameter method parameter} is
* supported by any registered {@link HandlerMethodArgumentResolver}.
*/
@Override
public boolean supportsParameter(MethodParameter parameter) {
return getArgumentResolver(parameter) != null;
}
/**
* Iterate over registered
* {@link HandlerMethodArgumentResolver HandlerMethodArgumentResolvers}
* and invoke the one that supports it.
* @throws IllegalStateException if no suitable
* {@link HandlerMethodArgumentResolver} is found.
*/
@Override
@Nullable
public Object resolveArgument(MethodParameter parameter, Message message) throws Exception {
HandlerMethodArgumentResolver resolver = getArgumentResolver(parameter);
if (resolver == null) {
throw new IllegalStateException(
"Unsupported parameter type [" + parameter.getParameterType().getName() + "]." +
" supportsParameter should be called first.");
}
return resolver.resolveArgument(parameter, message);
}
/**
* Find a registered {@link HandlerMethodArgumentResolver} that supports
* the given method parameter.
*/
@Nullable
private HandlerMethodArgumentResolver getArgumentResolver(MethodParameter parameter) {
HandlerMethodArgumentResolver result = this.argumentResolverCache.get(parameter);
if (result == null) {
for (HandlerMethodArgumentResolver resolver : this.argumentResolvers) {
if (resolver.supportsParameter(parameter)) {
result = resolver;
this.argumentResolverCache.put(parameter, result);
break;
}
}
}
return result;
}
}