QueueMessageHandlerFactory.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.config;

import com.amazonaws.services.sqs.AmazonSQS;
import com.amazonaws.services.sqs.AmazonSQSAsync;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.cloud.aws.core.env.ResourceIdResolver;
import org.springframework.cloud.aws.messaging.core.QueueMessagingTemplate;
import org.springframework.cloud.aws.messaging.listener.QueueMessageHandler;
import org.springframework.cloud.aws.messaging.listener.SendToHandlerMethodReturnValueHandler;
import org.springframework.messaging.core.DestinationResolvingMessageSendingOperations;
import org.springframework.messaging.handler.invocation.HandlerMethodArgumentResolver;
import org.springframework.messaging.handler.invocation.HandlerMethodReturnValueHandler;
import org.springframework.util.CollectionUtils;

import java.util.List;

/**
 * @author Alain Sahli
 * @since 1.0
 */
public class QueueMessageHandlerFactory {

    private List<HandlerMethodArgumentResolver> argumentResolvers;

    private List<HandlerMethodReturnValueHandler> returnValueHandlers;

    private DestinationResolvingMessageSendingOperations<?> sendToMessagingTemplate;

    private AmazonSQSAsync amazonSqs;

    private ResourceIdResolver resourceIdResolver;

    private BeanFactory beanFactory;

    public void setArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
        this.argumentResolvers = argumentResolvers;
    }

    public void setReturnValueHandlers(List<HandlerMethodReturnValueHandler> returnValueHandlers) {
        this.returnValueHandlers = returnValueHandlers;
    }

    /**
     * Configures the {@link DestinationResolvingMessageSendingOperations} template
     * used by the {@link SendToHandlerMethodReturnValueHandler} to
     * send return values of handler methods.
     *
     * @param sendToMessagingTemplate
     *         A {@link DestinationResolvingMessageSendingOperations} template for
     *         sending return values of handler methods.
     */
    public void setSendToMessagingTemplate(DestinationResolvingMessageSendingOperations<?> sendToMessagingTemplate) {
        this.sendToMessagingTemplate = sendToMessagingTemplate;
    }

    /**
     * <p>Sets the {@link AmazonSQS} client that is going to be used to create a new
     * {@link QueueMessagingTemplate} if {@code sendToMessagingTemplate} is
     * {@code null}. This template is used by the
     * {@link SendToHandlerMethodReturnValueHandler} to send the return
     * values of handler methods annotated with {@link org.springframework.messaging.handler.annotation.SendTo}.</p>
     * <p>An {@link AmazonSQS} client is only needed if {@code sendToMessagingTemplate} is
     * {@code null}.</p>
     *
     * @param amazonSqs
     *         The {@link AmazonSQS} client that is going to be used by the
     *         {@link SendToHandlerMethodReturnValueHandler} to send
     *         messages.
     */
    public void setAmazonSqs(AmazonSQSAsync amazonSqs) {
        this.amazonSqs = amazonSqs;
    }

    public AmazonSQS getAmazonSqs() {
        return this.amazonSqs;
    }

    /**
     * This value is only used if no {@code sendToMessagingTemplate} has been set.
     *
     * @param resourceIdResolver
     *         the resourceIdResolver to use for resolving logical to physical ids in a CloudFormation environment. This
     *         resolver will be used by the {@link QueueMessagingTemplate}
     *         created for the {@link SendToHandlerMethodReturnValueHandler}.
     */
    public void setResourceIdResolver(ResourceIdResolver resourceIdResolver) {
        this.resourceIdResolver = resourceIdResolver;
    }

    /**
     * Configures a {@link BeanFactory} that should be used to resolve expressions and placeholder for
     * {@link org.springframework.messaging.handler.annotation.SendTo} annotations. If not set, then no
     * expressions or place holders will be resolved.
     *
     * @param beanFactory
     *         - the bean factory used to resolve expressions and / or place holders
     */
    public void setBeanFactory(BeanFactory beanFactory) {
        this.beanFactory = beanFactory;
    }

    public QueueMessageHandler createQueueMessageHandler() {
        QueueMessageHandler queueMessageHandler = new QueueMessageHandler();

        if (!CollectionUtils.isEmpty(this.argumentResolvers)) {
            queueMessageHandler.getCustomArgumentResolvers().addAll(this.argumentResolvers);
        }
        if (!CollectionUtils.isEmpty(this.returnValueHandlers)) {
            queueMessageHandler.getCustomReturnValueHandlers().addAll(this.returnValueHandlers);
        }

        SendToHandlerMethodReturnValueHandler sendToHandlerMethodReturnValueHandler;
        if (this.sendToMessagingTemplate != null) {
            sendToHandlerMethodReturnValueHandler = new SendToHandlerMethodReturnValueHandler(this.sendToMessagingTemplate);
        } else {
            sendToHandlerMethodReturnValueHandler = new SendToHandlerMethodReturnValueHandler(
                    getDefaultSendToQueueMessagingTemplate(this.amazonSqs, this.resourceIdResolver));

        }
        sendToHandlerMethodReturnValueHandler.setBeanFactory(this.beanFactory);
        queueMessageHandler.getCustomReturnValueHandlers().add(sendToHandlerMethodReturnValueHandler);

        return queueMessageHandler;
    }

    private QueueMessagingTemplate getDefaultSendToQueueMessagingTemplate(AmazonSQSAsync amazonSqs, ResourceIdResolver resourceIdResolver) {
        return new QueueMessagingTemplate(amazonSqs, resourceIdResolver);
    }
}