org.rifidi.app.amazonsample.DynamoDBApp.java Source code

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Here is the source code for org.rifidi.app.amazonsample.DynamoDBApp.java

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/*******************************************************************************
 * Copyright (c) 2014 Transcends, LLC.
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU 
 * General Public License as published by the Free Software Foundation; either version 2 of the 
 * License, or (at your option) any later version. This program is distributed in the hope that it will 
 * be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You 
 * should have received a copy of the GNU General Public License along with this program; if not, 
 * write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 
 * USA. 
 * http://www.gnu.org/licenses/gpl-2.0.html
 *******************************************************************************/
package org.rifidi.app.amazonsample;

import java.util.LinkedList;
import java.util.List;
import java.util.concurrent.TimeUnit;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.rifidi.edge.api.AbstractRifidiApp;
import org.rifidi.edge.api.service.tagmonitor.ReadZone;
import org.rifidi.edge.api.service.tagmonitor.ReadZoneMonitoringService;
import org.rifidi.edge.api.service.tagmonitor.ReadZoneSubscriber;

import com.amazonaws.AmazonServiceException;
import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.services.dynamodb.AmazonDynamoDBClient;
import com.amazonaws.services.dynamodb.model.DescribeTableRequest;
import com.amazonaws.services.dynamodb.model.TableDescription;
import com.amazonaws.services.dynamodb.model.TableStatus;

public class DynamoDBApp extends AbstractRifidiApp {

    /** The logger for this class */
    //private static Log logger = LogFactory.getLog(DynamoDBApp.class);

    private AmazonDynamoDBClient dynamoDB;

    /** The service for monitoring arrival and departure events */
    private ReadZoneMonitoringService readZoneMonitoringService;

    private List<ReadZoneSubscriber> subscriberList;

    /**
     * 
     * 
     * @param group
     * @param name
     */
    public DynamoDBApp(String group, String name) {
        super(group, name);

        AWSCredentials cred = new AWSCredentials() {

            @Override
            public String getAWSSecretKey() {
                return "PUT SECRET HERE";
            }

            @Override
            public String getAWSAccessKeyId() {
                return "PUT KEY HERE";
            }
        };

        dynamoDB = new AmazonDynamoDBClient(cred);
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.rifidi.edge.api.AbstractRifidiApp#initialize()
     */
    @Override
    public void initialize() {
    }

    /**
     * Start the application. This method submits the esper statements to the
     * esper runtime.
     */
    @Override
    public void _start() {
        super._start();

        String tableName = "epc-tags";

        waitForTableToBecomeAvailable(tableName);

        DynamoDBSubscriber sub = new DynamoDBSubscriber(this.dynamoDB, tableName);
        this.subscriberList = new LinkedList<ReadZoneSubscriber>();
        this.subscriberList.add(sub);
        this.readZoneMonitoringService.subscribe(sub, new LinkedList<ReadZone>(), 4.0f, TimeUnit.SECONDS, true);
    }

    /**
     * Iterate through all statements and stop them.
     */
    @Override
    public void _stop() {
        for (ReadZoneSubscriber s : this.subscriberList) {
            this.readZoneMonitoringService.unsubscribe(s);
        }
    }

    /**
     * Called by spring. This method injects the ReadZoneMonitoringService into
     * the application.
     * 
     * @param rzms
     */
    public void setReadZoneMonitoringService(ReadZoneMonitoringService rzms) {
        this.readZoneMonitoringService = rzms;
    }

    private void waitForTableToBecomeAvailable(String tableName) {
        System.out.println("Waiting for " + tableName + " to become ACTIVE...");

        long startTime = System.currentTimeMillis();
        long endTime = startTime + (10 * 60 * 1000);
        while (System.currentTimeMillis() < endTime) {
            try {
                Thread.sleep(1000 * 20);
            } catch (Exception e) {
                e.printStackTrace();
            }
            try {
                DescribeTableRequest request = new DescribeTableRequest().withTableName(tableName);
                TableDescription tableDescription = dynamoDB.describeTable(request).getTable();
                String tableStatus = tableDescription.getTableStatus();
                System.out.println("  - current state: " + tableStatus);
                if (tableStatus.equals(TableStatus.ACTIVE.toString()))
                    return;
            } catch (AmazonServiceException ase) {
                if (ase.getErrorCode().equalsIgnoreCase("ResourceNotFoundException") == false) {
                    throw ase;
                }
            }
        }

        throw new RuntimeException("Table " + tableName + " never went active");
    }

}