com.erudika.para.queue.AWSQueue.java Source code

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Here is the source code for com.erudika.para.queue.AWSQueue.java

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/*
 * Copyright 2013-2015 Erudika. http://erudika.com
 *
 * 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.
 *
 * For issues and patches go to: https://github.com/erudika
 */
package com.erudika.para.queue;

import com.amazonaws.AmazonClientException;
import com.amazonaws.AmazonServiceException;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.regions.Region;
import com.amazonaws.regions.Regions;
import com.amazonaws.services.sqs.AmazonSQSAsyncClient;
import com.amazonaws.services.sqs.AmazonSQSClient;
import com.amazonaws.services.sqs.model.CreateQueueRequest;
import com.amazonaws.services.sqs.model.DeleteMessageRequest;
import com.amazonaws.services.sqs.model.Message;
import com.amazonaws.services.sqs.model.ReceiveMessageRequest;
import com.amazonaws.services.sqs.model.SendMessageRequest;
import com.erudika.para.Para;
import com.erudika.para.utils.Config;
import java.util.List;
import org.slf4j.Logger;
import javax.inject.Singleton;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.LoggerFactory;

/**
 * An implementation of the {@link Queue} interface using the AWS Simple Queue Service.
 * @author Alex Bogdanovski [alex@erudika.com]
 */
@Singleton
public class AWSQueue implements Queue {

    private static final int MAX_MESSAGES = 1; //max in bulk
    private AmazonSQSAsyncClient sqs;
    private static final String SQS_ENDPOINT = "https://sqs.".concat(Config.AWS_REGION).concat(".amazonaws.com");
    private static final Logger logger = LoggerFactory.getLogger(AWSQueue.class);
    private String name;
    private String endpoint;
    private String url;

    /**
     * No-args constructor
     */
    public AWSQueue() {
        this("test123", SQS_ENDPOINT);
    }

    /**
     * Default consturctor.
     * This queue contains only messages in JSON format.
     * @param name name of the queue
     * @param endpoint endpoint url
     */
    public AWSQueue(String name, String endpoint) {
        this.endpoint = StringUtils.isBlank(endpoint) ? SQS_ENDPOINT : endpoint;
        this.name = name;
        this.url = create(name);
    }

    AmazonSQSClient client() {
        if (sqs != null) {
            return sqs;
        }
        sqs = new AmazonSQSAsyncClient(new BasicAWSCredentials(Config.AWS_ACCESSKEY, Config.AWS_SECRETKEY));
        sqs.setRegion(Region.getRegion(Regions.fromName(Config.AWS_REGION)));
        sqs.setEndpoint(this.endpoint);

        Para.addDestroyListener(new Para.DestroyListener() {
            public void onDestroy() {
                sqs.shutdown();
            }
        });
        return sqs;
    }

    @Override
    public void push(String task) {
        if (!StringUtils.isBlank(url) && task != null) {
            // only allow strings - ie JSON
            if (!StringUtils.isBlank(task)) {
                // Send a message
                try {
                    SendMessageRequest sendReq = new SendMessageRequest();
                    sendReq.setQueueUrl(url);
                    sendReq.setMessageBody(task);

                    client().sendMessage(sendReq);
                } catch (AmazonServiceException ase) {
                    logException(ase);
                } catch (AmazonClientException ace) {
                    logger.error("Could not reach SQS. {}", ace.toString());
                }
            }
        }
    }

    @Override
    public String pull() {
        String task = "[]";
        if (!StringUtils.isBlank(url)) {
            try {
                ReceiveMessageRequest receiveReq = new ReceiveMessageRequest(url);
                receiveReq.setMaxNumberOfMessages(MAX_MESSAGES);
                List<Message> list = client().receiveMessage(receiveReq).getMessages();

                if (list != null && !list.isEmpty()) {
                    Message message = list.get(0);
                    client().deleteMessage(new DeleteMessageRequest(url, message.getReceiptHandle()));
                    task = message.getBody();
                }
            } catch (AmazonServiceException ase) {
                logException(ase);
            } catch (AmazonClientException ace) {
                logger.error("Could not reach SQS. {}", ace.toString());
            }
        }
        return task;
    }

    @Override
    public String getName() {
        return name;
    }

    @Override
    public void setName(String name) {
        this.name = name;
    }

    private String create(String name) {
        String u = endpoint.concat("/").concat(name);
        try {
            u = client().createQueue(new CreateQueueRequest(name)).getQueueUrl();
        } catch (AmazonServiceException ase) {
            logException(ase);
        } catch (AmazonClientException ace) {
            logger.error("Could not reach SQS. {0}", ace.toString());
        }
        return u;
    }
    //
    //   public void delete() {
    //      try {
    //         client().deleteQueue(new DeleteQueueRequest(QUEUE_URL));
    //      } catch (AmazonServiceException ase) {
    //         logException(ase);
    //      } catch (AmazonClientException ace) {
    //         logger.error("Could not reach SQS. {0}", ace.toString());
    //      }
    //   }
    //
    //   public List<String> listQueues() {
    //      List<String> list = null;
    //      try {
    //         list = client().listQueues().getQueueUrls();
    //      } catch (AmazonServiceException ase) {
    //         logException(ase);
    //      } catch (AmazonClientException ace) {
    //         logger.error("Could not reach SQS. {0}", ace.toString());
    //      }
    //      return list;
    //   }

    private void logException(AmazonServiceException ase) {
        logger.error("AmazonServiceException: error={}, statuscode={}, " + "awserrcode={}, errtype={}, reqid={}",
                ase.toString(), ase.getStatusCode(), ase.getErrorCode(), ase.getErrorType(), ase.getRequestId());
    }
}