org.springframework.messaging.handler.annotation.support.DestinationVariableMethodArgumentResolver 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.annotation.support;
import java.util.Map;
import org.springframework.core.MethodParameter;
import org.springframework.core.convert.ConversionService;
import org.springframework.lang.Nullable;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageHandlingException;
import org.springframework.messaging.handler.annotation.DestinationVariable;
import org.springframework.messaging.handler.annotation.ValueConstants;
import org.springframework.util.Assert;
/**
* Resolves method parameters annotated with
* {@link org.springframework.messaging.handler.annotation.DestinationVariable @DestinationVariable}.
*
* @author Brian Clozel
* @since 4.0
*/
public class DestinationVariableMethodArgumentResolver extends AbstractNamedValueMethodArgumentResolver {
/**
* The name of the header used to for template variables.
*/
public static final String DESTINATION_TEMPLATE_VARIABLES_HEADER =
DestinationVariableMethodArgumentResolver.class.getSimpleName() + ".templateVariables";
public DestinationVariableMethodArgumentResolver(ConversionService cs) {
super(cs, null);
}
@Override
public boolean supportsParameter(MethodParameter parameter) {
return parameter.hasParameterAnnotation(DestinationVariable.class);
}
@Override
protected NamedValueInfo createNamedValueInfo(MethodParameter parameter) {
DestinationVariable annotation = parameter.getParameterAnnotation(DestinationVariable.class);
Assert.state(annotation != null, "No DestinationVariable annotation");
return new DestinationVariableNamedValueInfo(annotation);
}
@Override
@Nullable
protected Object resolveArgumentInternal(MethodParameter parameter, Message message, String name)
throws Exception {
@SuppressWarnings("unchecked")
Map vars =
(Map) message.getHeaders().get(DESTINATION_TEMPLATE_VARIABLES_HEADER);
return (vars != null ? vars.get(name) : null);
}
@Override
protected void handleMissingValue(String name, MethodParameter parameter, Message message) {
throw new MessageHandlingException(message, "Missing path template variable '" + name +
"' for method parameter type [" + parameter.getParameterType() + "]");
}
private static final class DestinationVariableNamedValueInfo extends NamedValueInfo {
private DestinationVariableNamedValueInfo(DestinationVariable annotation) {
super(annotation.value(), true, ValueConstants.DEFAULT_NONE);
}
}
}