AcknowledgmentHandlerMethodArgumentResolver.java

/*
 * Copyright 2013-2014 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.cloud.aws.messaging.listener.support;

import org.springframework.cloud.aws.messaging.listener.Acknowledgment;
import org.springframework.core.MethodParameter;
import org.springframework.messaging.Message;
import org.springframework.messaging.handler.invocation.HandlerMethodArgumentResolver;
import org.springframework.util.ClassUtils;

/**
 * @author Alain Sahli
 * @since 1.1
 */
public class AcknowledgmentHandlerMethodArgumentResolver implements HandlerMethodArgumentResolver {

    private final String acknowledgmentHeaderName;

    public AcknowledgmentHandlerMethodArgumentResolver(String acknowledgmentHeaderName) {
        this.acknowledgmentHeaderName = acknowledgmentHeaderName;
    }

    @Override
    public boolean supportsParameter(MethodParameter parameter) {
        return ClassUtils.isAssignable(Acknowledgment.class, parameter.getParameterType());
    }

    @Override
    public Object resolveArgument(MethodParameter parameter, Message<?> message) throws Exception {
        if (!message.getHeaders().containsKey(this.acknowledgmentHeaderName) ||
                message.getHeaders().get(this.acknowledgmentHeaderName) == null) {
            throw new IllegalArgumentException("No acknowledgment object found for message header: '" + this.acknowledgmentHeaderName + "'");
        }
        return message.getHeaders().get(this.acknowledgmentHeaderName);
    }
}