DynamicTopicDestinationResolver.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.support.destination;

import com.amazonaws.services.sns.AmazonSNS;
import com.amazonaws.services.sns.model.CreateTopicRequest;
import com.amazonaws.services.sns.model.ListTopicsRequest;
import com.amazonaws.services.sns.model.ListTopicsResult;
import com.amazonaws.services.sns.model.Topic;
import org.springframework.cloud.aws.core.env.ResourceIdResolver;
import org.springframework.cloud.aws.core.naming.AmazonResourceName;
import org.springframework.messaging.core.DestinationResolutionException;
import org.springframework.messaging.core.DestinationResolver;
import org.springframework.util.StringUtils;

/**
 * @author Agim Emruli
 * @author Alain Sahli
 * @since 1.0
 */
public class DynamicTopicDestinationResolver implements DestinationResolver<String> {

    private final AmazonSNS amazonSns;
    private final ResourceIdResolver resourceIdResolver;
    private boolean autoCreate;

    public DynamicTopicDestinationResolver(AmazonSNS amazonSns, ResourceIdResolver resourceIdResolver) {
        this.amazonSns = amazonSns;
        this.resourceIdResolver = resourceIdResolver;
    }

    public DynamicTopicDestinationResolver(AmazonSNS amazonSns) {
        this(amazonSns, null);
    }

    public void setAutoCreate(boolean autoCreate) {
        this.autoCreate = autoCreate;
    }

    @Override
    public String resolveDestination(String name) throws DestinationResolutionException {
        if (this.autoCreate) {
            return this.amazonSns.createTopic(new CreateTopicRequest(name)).getTopicArn();
        } else {
            String physicalTopicName = name;
            if (this.resourceIdResolver != null) {
                physicalTopicName = this.resourceIdResolver.resolveToPhysicalResourceId(name);
            }

            if (physicalTopicName != null && AmazonResourceName.isValidAmazonResourceName(physicalTopicName)) {
                return physicalTopicName;
            }

            String topicArn = getTopicResourceName(null, physicalTopicName);
            if (topicArn == null) {
                throw new IllegalArgumentException("No Topic with name: '" + name + "' found. Please use " +
                        "the right topic name or enable auto creation of topics for this DestinationResolver");
            }
            return topicArn;
        }
    }

    private String getTopicResourceName(String marker, String topicName) {
        ListTopicsResult listTopicsResult = this.amazonSns.listTopics(new ListTopicsRequest(marker));
        for (Topic topic : listTopicsResult.getTopics()) {
            AmazonResourceName resourceName = AmazonResourceName.fromString(topic.getTopicArn());
            if (resourceName.getResourceType().equals(topicName)) {
                return topic.getTopicArn();
            }
        }

        if (StringUtils.hasText(listTopicsResult.getNextToken())) {
            return getTopicResourceName(listTopicsResult.getNextToken(), topicName);
        } else {
            throw new IllegalArgumentException("No topic found for name :'" + topicName + "'");
        }
    }
}