Open Rail Data Stomp client for Java

An example Stomp client for Java

NB The popular Gorizza library does not support receipt of binary data over STOMP, so will not be able to consume the GZIP stream coming across this wire.

Make use of the https://github.com/fusesource/stompjms library to add STOMP support to the lower level http://activemq.apache.org library.

build.gradle

compile (group: 'org.apache.activemq', name: 'activemq-client', version: '5.15.0')
compile group: 'org.fusesource.stompjms', name: 'stompjms-client', version: '1.19'

src/main/java/darwinStomp/StompClient

package darwinStomp;

import org.fusesource.stomp.jms.StompJmsConnectionFactory;
import javax.jms.*;

public class StompClient implements Runnable {

    public static void main(String[] args) throws Exception {
        new StompClient().run();
    }

    @Override
    public void run() {
        String brokerUri = "tcp://datafeeds.nationalrail.co.uk:61613";
        String QUEUE_NAME = "Your security key from My Feeds"

        StompJmsConnectionFactory connectionFactory = new StompJmsConnectionFactory();
        connectionFactory.setBrokerURI(brokerUri);

        Connection connection = null;
        Session session = null;
        MessageConsumer consumer = null;

        try {
            connection = connectionFactory.createConnection("d3user", "d3password");
            connection.start();

            session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
            Queue queue = session.createQueue(QUEUE_NAME);
            consumer = session.createConsumer(queue);

            System.out.println("Connected to STOMP " + brokerUri);

            consumer.setMessageListener(new MessageHandler());

            while (!Thread.interrupted()) {}

            try {
                if (consumer != null) {
                    consumer.close();
                }

                if (session != null) {
                    session.close();
                }

                if (connection != null) {
                    connection.close();
                    connection = null;
                }
            } catch (JMSException ex) {
                System.out.println("Got exception on shutdown");
                ex.printStackTrace();
            }

            System.out.println("Thread was interrupted!");


        } catch (JMSException e) {
            e.printStackTrace();
        }
    }
}

src/main/java/darwinStomp/MessageHandler

package darwinStomp;

import javax.jms.BytesMessage;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageListener;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.util.zip.GZIPInputStream;

public class MessageHandler implements MessageListener {
    @Override
    public void onMessage(Message message) {
        String xmlString = convertToXmlString((BytesMessage) message);
        System.out.println(xmlString);
    }

    private String convertToXmlString(BytesMessage bytesMessage) {
        if (bytesMessage != null) try {
            long l = bytesMessage.getBodyLength();
            byte bytesArray[] = new byte[(int) l];
            bytesMessage.readBytes(bytesArray);
            Reader streamReader = null;
            try {
                streamReader = new InputStreamReader(new GZIPInputStream(new ByteArrayInputStream(bytesArray)));
                StringBuilder stringBuilder = new StringBuilder();
                char cb[] = new char[1024];
                int s = streamReader.read(cb);
                while (s > -1) {
                    stringBuilder.append(cb, 0, s);
                    s = streamReader.read(cb);
                }
                return stringBuilder.toString();
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                if (streamReader != null) {
                    streamReader.close();
                }
            }
        } catch (IOException ex) {
            System.out.println("Failed to parse message");
            ex.printStackTrace();
        } catch (JMSException ex) {
            System.out.println("Failed to parse message");
            ex.printStackTrace();
        }

        return null;
    }
}