it.polimi.modaclouds.cpimlibrary.msgqueuemng.AmazonMessageQueue.java Source code

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Here is the source code for it.polimi.modaclouds.cpimlibrary.msgqueuemng.AmazonMessageQueue.java

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/**
 * Copyright 2013 deib-polimi
 * Contact: deib-polimi <marco.miglierina@polimi.it>
 *
 *    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 it.polimi.modaclouds.cpimlibrary.msgqueuemng;

import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

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.GetQueueUrlRequest;
import com.amazonaws.services.sqs.model.GetQueueUrlResult;
import com.amazonaws.services.sqs.model.Message;
import com.amazonaws.services.sqs.model.ReceiveMessageRequest;
import com.amazonaws.services.sqs.model.SendMessageRequest;

public class AmazonMessageQueue implements CloudMessageQueue {

    private String queueName = null;
    private AmazonSQSClient sqs = null;
    private Map<String, String> receipts = new HashMap<String, String>();

    public AmazonMessageQueue(String queueName, AmazonSQSClient sqs) {
        this.queueName = queueName;
        this.sqs = sqs;
        CreateQueueRequest cqr = new CreateQueueRequest(queueName);
        sqs.createQueue(cqr);
    }

    @Override
    public void add(String msg) throws CloudMessageQueueException {
        GetQueueUrlRequest getQueueUrlRequest = new GetQueueUrlRequest(queueName);
        GetQueueUrlResult getQueueUrlResult = sqs.getQueueUrl(getQueueUrlRequest);
        String queueUrl = getQueueUrlResult.getQueueUrl();
        sqs.sendMessage(new SendMessageRequest(queueUrl, msg));
    }

    @Override
    public String getQueueName() {
        return queueName;
    }

    @Override
    public void purge() {
        String queueUrl = sqs.getQueueUrl(new GetQueueUrlRequest(queueName)).getQueueUrl();
        Set<String> keys = receipts.keySet();
        for (String key : keys) {
            sqs.deleteMessage(new DeleteMessageRequest(queueUrl, receipts.get(key)));
        }
        ReceiveMessageRequest receiveMessageRequest = new ReceiveMessageRequest(queueUrl);
        List<Message> messages = sqs.receiveMessage(receiveMessageRequest).getMessages();
        for (Message m : messages) {
            sqs.deleteMessage(new DeleteMessageRequest(queueUrl, m.getReceiptHandle()));
        }
        receipts.clear();
    }

    @Override
    public CloudMessage getMessage() {
        String msg = null;
        String id = null;
        String queueUrl = sqs.getQueueUrl(new GetQueueUrlRequest(queueName)).getQueueUrl();
        ReceiveMessageRequest receiveMessageRequest = new ReceiveMessageRequest(queueUrl);
        List<Message> messages = sqs.receiveMessage(receiveMessageRequest).getMessages();
        for (Message m : messages) {
            msg = m.getBody();
            id = m.getMessageId();
            receipts.put(id, m.getReceiptHandle());
            break;
        }
        CloudMessage cm = new CloudMessage(msg);
        cm.setId(id);
        return cm;
    }

    @Override
    public void deleteMessage(CloudMessage msg) throws CloudMessageQueueException {
        this.deleteMessage(msg.id);
    }

    @Override
    public void deleteMessage(String msgId) throws CloudMessageQueueException {
        String queueUrl = sqs.getQueueUrl(new GetQueueUrlRequest(queueName)).getQueueUrl();
        sqs.deleteMessage(new DeleteMessageRequest(queueUrl, receipts.get(msgId)));
        receipts.remove(msgId);
    }

}