Table of Contents

Introduction

This document article describes the implementation required for sending messages to a Java Message Queue Service queuewhich:

to send sends and receive receives messages,
to add adds an order to a JS7 workflow as an JS7 JOC by a JS7 - REST Web Service API call with a JSON body extracted from a message.

...

.

The Apache Active MQ server following Message Queue Service is used in this example: https://activemq.apache.org/.

Mode of Operation

The implementation enables includes the following steps:

Creation creation of a message producer to send messages to a Message Queue server (MQ server).Service,
creation Creation of a message consumer to receive messages from an MQ server.a Message Queue Service,
using the message as part of a JS7 REST Web Service API callSending the message to a JS7 JOC API.

The message has is assumed to be a JSON snippet to be which is processed by the desired JS7 JOC REST Web Service API. This snippet must be valid JSON and compliant with the JOC APIrequests explained in the Technical Documentation of the REST Web Service API article.

Most of the implementation work is done with the standard JMS implementation of Java. The only class from the Active MQ implementation is the ActiveMQConnectionFactory class. It shouldn´t be too complex to change the implementation to the ConnectionFactory of your desired message queue servicepreferred Message Queue Service.

Download

A zip file of this example as a complete maven project implementation is available for download: js7-jms-example-js7-project.zip.

Prerequisites

A running Message Queue server Service (The example uses Apache the example makes use of Active MQ)
A running JS7 Controller, Agent and JOC Cockpit.
Maven (required only needed if you users want to build the example as a maven Maven project)

The `MessageProducer`

This example describes how to build establish a connection to an MQ server a Message Queue Service and send a message to a queue on this server.

Create create a connection.,Create
create a session.,
Create create a destination.,Create
create a producer.,
Send send a message with the producer.,
Close close the connection.

...

Methods

The steps are separated into different methods to make the implementation more readable as well as reusable.

`createConnection(String url)`

This method instantiates a ConnectionFactory object with an ActiveMQConnectionFactory object and creates a Connection object through the factory method createConnection().

`write(String text)`

The method is called with the message to be sent to the server. The message is a String object. The method instantiates a Message object with the text to be sentThe ActiveMQConnectionFactory object has to be instantiated with the URL of the MQ server.

Code Block

language	java
title	createConnectionwrite(String urltext)
linenumbers	true
collapse	true

    public Connectionvoid createConnectionwrite(String uri){
    ConnectionFactory factory = new ActiveMQConnectionFactory(uri);
text, String queueName, long ttl) throws Exception {
        Connection connection = null;
    try {
   Session     connectionsession = factory.createConnection()null;
    }  catch (JMSException e)try {
        LOGGER.error("JMSException occurred while trying toConnectionFactory connect:factory "= ,new eActiveMQConnectionFactory(uri);
       }
    return connection;
}

createSession(Connection connection)

The method is called with an already instantiated Connection object and initiates a Session object through the Connection objects createSession(boolean transacted, int acknowledgeMode) method.

Code Block

language	java
title	createSession(Connection connection)
linenumbers	true
collapse	true

private Session createSession(Connection connection){
    Session session = null;
    try {
    = factory.createConnection();
            session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
    } catch (JMSException e) {
    Destination destination =  LOGGERsession.error("JMSException occurred while trying to create Session: " , e);
    }
    return session;
}

`createDestination(Session session, String queueName)`

This method creates a Destination object. It is called with an active Session object and the name of the queue to write to. The Destination object is initiated through the createQueue(String name) method of the Session object.

Code Block

language	java
title	createDestination(Session session)
linenumbers	true
collapse	true

public Destination createDestination(Session session, String queueName){
    Destination destinationcreateQueue(queueName);
            MessageProducer producer = session.createProducer(destination);
            // 5 sec time to live for the producer for this showcase
            producer.setTimeToLive(ttl);
            Message message = null;
    try {
       if(text destination != null){
                message = session.createQueuecreateTextMessage(queueNametext);
         } catch (JMSException e)} else{
         LOGGER.error("JMSException occurred while trying to create Destination: "message , e= session.createTextMessage(TEXT);
            }
           return destination;
}

`createMessageProducer(Session session, Destination destination)`

This method is called with an already active Session object as well as an instantiated Destination object. It instantiates a MessageProducer object with the given session and destination.

Code Block

language	java
title	createProducer(Session session, Destination destination)
linenumbers	true
collapse	true

private MessageProducer createMessageProducer(Session session, Destination destination) producer.send(message);
        } catch (Throwable e) {
    MessageProducer producer = null;
    try {
        producer = session.createProducer(destination);
 LOGGER.error("JMSException occurred while trying to write Message to Destination: ");
            throw e;
        } catch (JMSException e finally {
            if(session != null) {
        LOGGER.error("JMSException occurred while trying to create MessageProducer: " ,try e);{
      }         
    return producer;
}

`write(String text, MessageProducer producer)`

The method is called with the message to send to the server and the MessageProducer object to use for publishing. The message is a String object. The method instantiates a Message object with the text to send.

Code Block

language	java
title	write(String text)
linenumbers	true
collapse	true

public void write(String text, MessageProducer producer){
session.close();
           Message message = null;
  } catch try {(JMSException e) {
        if(text != null){
            LOGGER.warn("JMSException occurred while trying to messageclose =the session.createTextMessage(text: ", e);
        } else{
       }
     message = session.createTextMessage(DEFAULT_TEXT);
        }
        producer.send(message);
    }if catch (JMSException e(connection != null) {
        LOGGER.error("JMSException occurred while trying to write Message to Destination: " , e);try {
    }
}

`close()`

This method makes sure that the connection used will be closed after a message has been sent.

Code Block

language	java
title	close()
linenumbers	true
collapse	true

private void close(Connection connection){
    if (connection != null) {
        try {
   connection.close();
         connection.close();
        } catch (JMSException e) {
             LOGGER.error       LOGGER.warn("JMSException occurred while trying to close the connection: " , e);
                }
            }
        }
    }

The `SOSProducer` class

The code example below slightly differs from the examples above. In the class below the write(String text) method already uses the other methods for instantiation, therefore it needs less parameters and it closes the connection itself.

The text in the example below consists of a JobScheduler add_order XML, which can later be used to send to a JobScheduler.

shows the complete class. The code creates a TEXT message consisting of the body for a JS7 /orders/add API request.

Code Block

language	java
title	SOSProducer.java
linenumbers	true
collapse	true

package com.sos.jms.producer;

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageProducer;
import javax.jms.Session;

import org.apache.activemq.ActiveMQConnectionFactory;
import org.apache.log4j.Logger;


public class SOSProducer {
    private static final String DEFAULT_CONNECTION_URI = "tcp://[HOSTNAME]:61616";
    private static final Logger LOGGER = Logger.getLogger(SOSProducer.class);
    private static final String QUEUE_NAME = "test_queue";
    private static final String DEFAULT_TEXT = "{\"controllerId\":\"testsuite\",\"orders\":[{\"workflowPath\":\"/JS7Demo/01_HelloWorld/jdHelloWorld\",\"scheduledFor\":\"now\"}],\"auditLog\":{}}";
    
private String uri;
  private Connection createConnection(){
    public SOSProducer(String uri)  return{
        this.createConnection(DEFAULT_CONNECTION_URI)uri = uri;
    }
    
    public Connectionvoid createConnectionwrite(String text, String uriqueueName) throws Exception {
        ConnectionFactory factory = new ActiveMQConnectionFactory(uriwrite(text, queueName, 5000L);
    }
    
  Connection connection =public null;
        tryvoid write(String text, String queueName, long ttl) throws Exception {
          Connection  connection = factory.createConnection()null;
        }Session catchsession (JMSException e) {= null;
        try {
   LOGGER.error("JMSException occurred while trying to connect: " , e);
 ConnectionFactory factory = new ActiveMQConnectionFactory(uri);
   }
        return connection = factory.createConnection();
    }
    
    privatesession Session= connection.createSession(Connection connection){false, Session.AUTO_ACKNOWLEDGE);
        Session session = null;
 Destination destination = session.createQueue(queueName);
    try {
       MessageProducer producer =   session = connection.createSession(false, Session.AUTO_ACKNOWLEDGEcreateProducer(destination);
          } catch (JMSException e) {
            LOGGER.error("JMSException occurred while trying to create Session: " , e// 5 sec time to live for the producer for this showcase
            producer.setTimeToLive(ttl);
        }
    Message message =  return sessionnull;
    }
    
    private Destination createDestinationif(Sessiontext session, String queueName!= null){
        Destination destination = null;
     message =  try session.createTextMessage(text);
            } else{
            destination    message = session.createQueue(queueNamecreateTextMessage(TEXT);
            }
            producer.send(message);
        } catch (JMSExceptionThrowable e) {
            LOGGER.error("JMSException occurred while trying to write Message createto Destination: " , e);
        }
    throw e;
   return destination;
    } finally {
    
    private MessageProducer createMessageProducer  if(Session session, Destination!= destinationnull) {
        MessageProducer    producer = null;
  try {
     try {
            producer = session.createProducerclose(destination);
                } catch (JMSException e) {
                    LOGGER.errorwarn("JMSException occurred while trying to close createthe MessageProducersession: " , e);
        }        }
        return producer;
    }
       
    public voidif write(String text)connection != null) {
         Connection connection = createConnection();
    try {
   Session session = createSession(connection);
            Destination destination = createDestinationconnection.close(session);
        MessageProducer producer = createMessageProducer(session, destination);
    } catch (JMSException e) Message{
 message = null;
        try {
        LOGGER.warn("JMSException occurred while trying to close the if(text != null){connection: ", e);
                message = session.createTextMessage(text);}
            } else{
        }
        message = session.createTextMessage(DEFAULT_TEXT)}
    
}

The `MessageConsumer`

This section describes how to establish a connection to a Message Queue Service and receive a message from a queue. Furthermore it shows how to connect to a JOC Cockpit instance via HTTP to send an API request:

create a connection,
create a session,
create a destination.
create a consumer,
receive a message with the consumer,
close the (MQ) connection,
login to a JOC Cockpit instance via a HTTP REST API call,
send a ./orders/add API request to a JOC Cockpit instance,
close the connection.

Methods

`read()`

The method instantiates a MessageConsumer object to receive a message from the Message Queue Service. It extracts the value from the Message object as a string representation via the Message objects getText() method.

Code Block

language	java
title	read()
linenumbers	true
collapse	true

    public String read(String queueName) throws Exception {
        TextMessage message = null;
        String textMessage = null;
        Connection connection = null;
        Session session = null;
        try {
            ConnectionFactory factory = new ActiveMQConnectionFactory(uri);
            connection = factory.createConnection();
            session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
            Destination destination = session.createQueue(queueName);
            connection.start();
            MessageConsumer consumer = session.createConsumer(destination);
            while (true) {
                Message receivedMessage = consumer.receive(1);
                if (receivedMessage != null) {
                    if (receivedMessage instanceof TextMessage) {
                        message = (TextMessage) receivedMessage;
            }
            textMessage = producermessage.sendgetText(message);
        } catch (JMSException e) {
            LOGGER.error("JMSException occurred while trying to write Message to Destination: " , e);
info("Reading message: " + textMessage);
                        break;
                    } finallyelse {
             if (connection != null) {
           break;
                   try {}
                }
    connection.close();
        }
        } catch (JMSExceptionThrowable e) {
                    LOGGER.error("JMSException occurred while trying to closeread thefrom connectionDestination: " , e);
   );
            throw e;
        } finally {
            if(session != null) {
             }
   try {
        }
        }
    }
}

The `MessageConsumer`

This section describes how to build a connection to a MQ server and receive a message from a queue on this server. Furthermore it describes how to build a TCP socket connection to send the received message to a JobScheduler.

Create a connection.
Create a session.
Create a destination.
Create a consumer.
Receive a message with the consumer.
Close the (MQ) connection.
Open a TCP connection to a JobScheduler instance.
Send the Message to the JobScheduler
Close the (TCP) connection.

This section shows examples for the last 5 steps as the first four are similar to the examples already shown above for the instantiation of the MessageProducer.

The Methods

`createMessageConsumer(Session session, Destination destination)`

This method is called with an already active Session object as well as an instantiated Destination object. It instantiates a MessageConsumer object with the given session and destination.

Code Block

language	java
title	createMessageConsumer(Session session, Destination destination)
linenumbers	true
collapse	true

private MessageConsumer createMessageConsumer(Session session, Destination destination) {
    MessageConsumer consumer = null;
session.close();
                } catch (JMSException e) {
                    LOGGER.warn("JMSException occurred while trying to close the session: ", e);
                }
            }
            if (connection != null) {
                try {
                 consumer  = sessionconnection.createConsumerclose(destination);

                } catch (JMSException e) {
                    LOGGER.errorwarn("JMSException occurred while trying to close createthe MessageConsumerconnection: ", e);
                }
            }
         }
        return consumer;
}

`read(MessageConsumer consumer)`

textMessage;
    }

The `SOSConsumer` class

The code example below shows the complete classThe method is called with an already instantiated MessageConsumer object to receive a message from the MQ server. It extracts the value from the Message object as a string representation via the Message objects getText() method.

Code Block

language	java
title	read()SOSConsumer
linenumbers	true
collapse	true

private String read(MessageConsumer consumer) {
    TextMessage message = null;
    String textMessage = null;
    try {
        while (true) {
            Message receivedMessage = consumer.receive(1);
            if (receivedMessage != null) {
                if (receivedMessage instanceof TextMessagepackage com.sos.jms.consumer;

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.Session;
import javax.jms.TextMessage;

import org.apache.activemq.ActiveMQConnectionFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class SOSConsumer {

    private static final Logger LOGGER = LoggerFactory.getLogger(SOSConsumer.class);
    private String uri;
    
    public SOSConsumer (String uri) {
                    message = (TextMessage) receivedMessagethis.uri = uri;
    }
    
    public String       textMessage = message.getText();
           read(String queueName) throws Exception {
        TextMessage LOGGER.info("Reading message: " + textMessage)= null;
        String textMessage = null;
        Connection connection = breaknull;
        Session session = null;
       } elsetry {
            ConnectionFactory factory =      breaknew ActiveMQConnectionFactory(uri);
            connection = factory.createConnection();
   }
         session =  }
connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
         }
   Destination }destination catch= (JMSException e) {session.createQueue(queueName);
        LOGGER.error("JMSException occurred while trying to read from Destination: ", e);
 connection.start();
         }
   MessageConsumer return textMessage;
}

Note
Don´t forget to clean up (call `close()`) after the message has been received.

`connect(String host, int port)`

This method instantiates a TCP socket connection to a JobScheduler instance with the given host:port.

Code Block

language	java
title	connect()
linenumbers	true
collapse	true

public void connect(String host, int port) throws Exception {
    if (host == null || host.length() == 0) {
consumer = session.createConsumer(destination);
            while (true) {
                Message receivedMessage = consumer.receive(1);
                if (receivedMessage != null) {
         throw (new Exception("hostname missing."));
    }
    if (portreceivedMessage ==instanceof 0TextMessage) {
       throw (new Exception("port missing."));
              }
   message if= ("udp".equalsIgnoreCase(PROTOCOL)TextMessage) {
receivedMessage;
              udpSocket  = new DatagramSocket();
      textMessage = udpSocket.connect(InetAddress.getByName(HOST), PORT);
message.getText();
           } else {
        socket = new Socket(host, portLOGGER.info("Reading message: " + textMessage);
         in = new DataInputStream(socket.getInputStream());
        out = new PrintWriter(socket.getOutputStream(), true) break;
      }
}

`disconnect()`

This method is used to close the socket opened with the above connect() method.

Code Block

language	java
title	disconnect()
linenumbers	true
collapse	true

public void disconnect() throws Exception {
              } else {
            if (socket != null) {
        socket.close()break;
            }
    if (in != null) {}
            in.close();
    }
    if (out != null) {
     }
   out.close();
     }
}

`sendRequest(String command)`

This method sends a request with the given command to the connected JobScheduler instance. The command given in the example is the add_order XML snippet shown in the SOSProducer example.

Code Block

language	java
linenumbers	true
collapse	true

public void sendRequest(String command) throws Exception {
 catch (Throwable e) {
           if LOGGER.error("udp".equalsIgnoreCase(PROTOCOL)) {
        if (command.indexOf("<?xml") == -1) {
JMSException occurred while trying to read from Destination: ");
            throw e;
  command = "<?xml version=\"1.0\" encoding=\"iso-8859-1\"?>" + command} + "\r\n";
finally {
         }
   if(session != null) {
  byte[] commandBytes = command.getBytes();
        udpSocket.send(new DatagramPacket(commandBytes, commandBytes.length, InetAddress.getByName(HOST), PORT));
 try {
         } else {
        if (commandsession.indexOfclose("<?xml");
 == 0) {
            out.print(command + "\r\n");
   } catch (JMSException e) {
     } else {
            out.print("<?xml version=\"1.0\" encoding=\"iso-8859-1\"?>" + command + "\r\n" LOGGER.warn("JMSException occurred while trying to close the session: ", e);
        }
        out.flush();}
    }
}

`getResponse()`

This message receives the response of the TCP connection described above.

Code Block

language	java
linenumbers	true
collapse	true

public String getResponse() throws IOException, RuntimeException {
        }
     int sec = 0;
    byte[] buffer = {};if (connection != null) {
    while (in.available() == 0) {
        try {
                    Threadconnection.sleepclose(1000);
                } catch (InterruptedExceptionJMSException e) {
            LOGGER.error("", e);
        }
        if (sec++ == TIMEOUT) {
LOGGER.warn("JMSException occurred while trying to close the connection: ", e);
             throw new RuntimeException("timeout reached"); }
        }
    }
     buffer  = new byte[in.available()];
 }
     int  bytesRead = in.read(buffer)return textMessage;
    return new String(buffer, "ISO-8859-1");
}

`receiveFromQueue()`

}

}

Java Class with a `main(String[] args)` method (example `JmsExecute.java`)

The Java class makes use of the SOSProducer to create a message and send it to the message queue. It then uses the SOSConsumer class to read the message from the queue. In addition, it creates an HTTP connection to a JS7 JOC Cockpit instance to call the /orders/add API with the JSON body from the message received.

The example class uses the SOSRestApiClient to create the HTTP connection. The SOSRestApiClient is based on the org.apache.httpcomponents::httpclient. Users can use their own HTTP client implementation. The receiveFromQueue() method uses the methods described above to connect to a host running a JobScheduler instance, read from a message queue, send the received message to the JobScheduler instance and close the session to the JobScheduler instance.

Code Block

language	java
title	receiveFromQueue()	linenumbers	trueJmsExecute.java
collapse	true

public String receiveFromQueue() {
    String message = null;
    try {
        connect();
        message = read();
        sendRequest(message);
        disconnect();
    } catch (Exception e) {
        LOGGER.error("Error occured while publishing to the JobScheduler instance host:" + HOST + ", port:" + PORT, e);
    }
    return message;
}

The `SOSConsumer` class

The code example below slightly differs from the examples above. In the class below the read() method already uses the other method for instantiation, therefore it needs less parameters and it closes the connection itself.

Code Block

language	java
title	SOSConsumer
linenumbers	true
collapse	true

package com.sos.jms.consumer;

import java.io.DataInputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.Socket;
import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.Session;
import javax.jms.TextMessage;
import org.apache.activemq.ActiveMQConnectionFactory;
import org.apache.log4j.Logger;

public class SOSConsumer {package com.sos.jms;

import java.io.IOException;
import java.io.StringReader;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Base64;
import java.util.Properties;

import javax.json.Json;
import javax.json.JsonObject;
import javax.json.JsonReader;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.sos.commons.httpclient.SOSRestApiClient;
import com.sos.jms.consumer.SOSConsumer;
import com.sos.jms.producer.SOSProducer;

public class JmsExecute {

    private static final String DEFAULT_JMS_URI = "tcp://activemq-5-15:61616";
    private static final String DEFAULT_JOC_API_URL = "http://centostest_primary.sos:7446/joc/api/";
    private static final String DEFAULT_JOC_API_REQUEST_BODY = "{\"controllerId\":\"testsuite\",\"orders\""
            + ":[{\"workflowPath\":\"/JS7Demo/01_HelloWorld/jdHelloWorld\",\"scheduledFor\":\"now\"}],\"auditLog\":{}}";
    private static final String DEFAULT_CONNECTION_URIUSERNAME = "tcp://[HOST]:61616root";
    private static final LoggerString LOGGERDEFAULT_PWD = Logger.getLogger(SOSConsumer.class)"root";
    private static final String DEFAULT_QUEUE_NAME = "test_queue";
    private static final String HOSTAPI_ADD_ORDER = "[JobScheduler_HOSTNAME]orders/add";
    private static final int PORT = [JobScheduler_PORT];
    private static final String PROTOCOLString API_LOGIN = "tcpauthentication/login";
    private static final int TIMEOUT = 5;
    private Socket socketString API_LOGOUT = null"authentication/logout";
    private static DatagramSocket udpSocketfinal String ACCESS_TOKEN_HEADER = null"X-Access-Token";
    private static final DataInputStreamString inAPPLICATION_JSON = null"application/json";
    private static PrintWriter outfinal String CONTENT_TYPE = null"Content-Type";

    private Connectionstatic createConnection() {
   final Logger LOGGER = LoggerFactory.getLogger(JmsExecute.class);
     return this.createConnection(DEFAULT_CONNECTION_URI);
    }
private static String jmsServerUri = null;
    private Connectionstatic createConnection(String jocApiUri uri)= {null;
    private static String  ConnectionFactory factorycontrollerId = new ActiveMQConnectionFactory(uri)null;
    private static String  Connection connectionworkflowPath = null;
    private static String requestBody try= {
     null;
    private static String username = null;
    private static String connectionpwd = factory.createConnection()null;
    private static String queueName = }null;
 catch (JMSException e) {
private static Long queueTtl = null;

    public static void LOGGER.error("JMSException occurred while trying to connect: ", e);
main(String[] args) throws URISyntaxException {
        SOSRestApiClient client = }null;
        returntry connection;{
    }

     private Session createSession(Connection connection)URL {
classUrl = JmsExecute.class.getProtectionDomain().getCodeSource().getLocation();
      Session session = null;
   Path classPath = Paths.get(classUrl.toURI());
  try {
         String  filename session = connection.createSession(false, Session.AUTO_ACKNOWLEDGEclassPath.getFileName().toString().replace(".jar", ".config");
         }  catch (JMSException e) {LOGGER.info(classPath.getParent().resolve(filename).toString());
            LOGGER.error("JMSException occurred while trying to create Session: ", ereadPropertiesFile(classPath.getParent().resolve(filename));
        }
     if   return session;("produce".equals(args[0])) {
    }

    private Destination createDestination(Session session) {
    SOSProducer producer = new return this.createDestination(session, DEFAULT_QUEUE_NAMESOSProducer(jmsServerUri);
          }
    private Destination createDestination(Session session, String queueName) {
 LOGGER.info("message send to queue:");
       Destination destination = null;
      LOGGER.info(requestBody);
  try {
            destination = sessionproducer.createQueuewrite(requestBody, queueName, queueTtl);
            } else catchif (JMSException e"consume".equals(args[0])) {
            LOGGER.error("JMSException occurred while trying toSOSConsumer createconsumer Destination:= ", enew SOSConsumer(jmsServerUri);
         }
       String consumedMessage return= destinationnull;
         }

    private MessageConsumer createMessageConsumer(Session session,consumedMessage Destination destination) {= consumer.read(queueName);
        MessageConsumer consumer = null;
     LOGGER.info("message received from queue:");
 try {
            consumer = sessionLOGGER.createConsumerinfo(destinationconsumedMessage);
               } catchif (JMSException econsumedMessage != null) {
               LOGGER.error("JMSException occurred while trying to createclient MessageConsumer: "= setupHttpClient(username, epwd);
              }
      URI jocUri return consumer;
= URI.create(jocApiUri);
       }

    private String read() {
      LOGGER.info("send login TextMessageto: message" = null+ jocUri.resolve(API_LOGIN).toString());
         String textMessage = null;
        ConnectionString connectionresponse = createConnection(client.postRestService(jocUri.resolve(API_LOGIN), null);
        try  {
          LOGGER.info("HTTP status Sessioncode: session" =+ createSessionclient.statusCode(connection));

                    Destination destinationif (client.statusCode() == createDestination(session);200) {
            connection.start();
            MessageConsumerJsonReader consumerjsonReader = createMessageConsumer(session, destination)null;
            while (true) {
          String accessToken = null;
   Message receivedMessage = consumer.receive(1);
                if (receivedMessage != null)try {
                            jsonReader = Json.createReader(new StringReader(response));
 if (receivedMessage instanceof TextMessage) {
                       JsonObject messagejson = jsonReader.readObject(TextMessage) receivedMessage;
                            textMessageaccessToken = messagejson.getText(getString("accessToken", "");
                        LOGGER.info("Reading message: " + textMessage);} catch (Exception e) {
                        break;
    throw new Exception("Could not determine   accessToken.", e);
         } else {
             }           break;
    finally {
                }
            jsonReader.close();
    }
            }
        }
 catch (JMSException e) {
            LOGGER.error("JMSException occurred while trying to read from Destination: " client.addHeader(ACCESS_TOKEN_HEADER, eaccessToken);
         } finally {
            if (connection != null) {client.addHeader(CONTENT_TYPE, APPLICATION_JSON);
                try {
       LOGGER.info("REQUEST: "            connection.close(+ API_ADD_ORDER);
                } catch (JMSException e) {
    LOGGER.info("PARAMS: " + consumedMessage);
             LOGGER.error("JMSException occurred while trying to close the connection: " , e);
 String apiUrl = null;
            }
            }
         }
if (!API_ADD_ORDER.toLowerCase().startsWith(jocApiUri)) {
         return textMessage;
    }

    public String receiveFromQueue() {
       apiUrl String= messagejocApiUri = null+ API_ADD_ORDER;
        try    {
            connect();}
            message  = read();
         LOGGER.info("resolvedUri: "  sendRequest(message+ jocUri.resolve(apiUrl).toString());
                disconnect();
        }response catch (Exception e) {= client.postRestService(jocUri.resolve(apiUrl), consumedMessage);
            LOGGER.error("Error occured while publishing to the JobScheduler instance host:" + HOST + ", port:LOGGER.info("HTTP status code: " + PORT, eclient.statusCode());
        }
        return message;
    }

   response public void connect(String host, int port) throws Exception {
   = client.postRestService(jocUri.resolve(API_LOGOUT), null);
     if (host == null || host.length() == 0) {
            throw (new Exception("hostname missing."LOGGER.info("HTTP status code: " + client.statusCode());
         }
        if (port == 0){}
            throw (new Exception("port missing."));
        }
        if ("udp".equalsIgnoreCase(PROTOCOL)) {
  }
        } catch udpSocket(Throwable = new DatagramSocket();e) {
            udpSocket.connect(InetAddress.getByName(HOST), PORTe.printStackTrace();
        } else {
    System.exit(1);
        socket} =finally new Socket(host, port);
{
            if (client in != new DataInputStream(socket.getInputStream());
null) {
             out = new PrintWriter(socketclient.getOutputStreamcloseHttpClient(), true);
        }
    }

    public void connect() throws Exception {}
    }

    this.connect(HOST, PORT);
    }

    /** sends a request to a JobScheduler
     *private static SOSRestApiClient setupHttpClient(String username, String password) {
        SOSRestApiClient client = new SOSRestApiClient();
     * @param command
 String basicAuth =  * @throws java.lang.Exception 
Base64.getMimeEncoder().encodeToString((username + ":" + password).getBytes());
        **/client.setBasicAuthorization(basicAuth);
    public  void sendRequest(String command) throws Exception {
  return client;
    }

    private static ifString ("udp".equalsIgnoreCase(PROTOCOL)cleanupValue(String value) {
        value = value.trim();
         if (commandvalue.indexOfstartsWith("<?xml\"") == -1) {
                commandvalue = "<?xml version=\"1.0\" encoding=\"iso-8859-1\"?>" + command + "\r\n";
    value.substring(1);
        }
            byte[] commandBytes =if command(value.getBytesendsWith();
"\"")) {
            value = udpSocketvalue.send(new DatagramPacket(commandBytessubstring(0, commandBytesvalue.length, InetAddress.getByName(HOST), - PORT)1);
        } else {
        return value;
   if (command.indexOf("<?xml") == 0) {
       }

    private static void readPropertiesFile(Path path) {
        Properties props out.print(command + "\r\n"= new Properties();
        try {
   } else {
       props.load(Files.newInputStream(path));
         out.print("<?xml version=\"1.0\" encoding=\"iso-8859-1\"?>" + command + "\r\n") jmsServerUri = cleanupValue(props.getProperty("jms_url"));
            }
            out.flush(LOGGER.info("cfg jms_url: " + jmsServerUri);
        }
    }

queueName = cleanupValue(props.getProperty("jms_queue_name"));
  /** receives the response of the JobScheduler for the last sent request
     * LOGGER.info("cfg jms_queue_name: " + queueName);
     * @return String response from JobScheduler
  queueTtl   * @throws IOException */= Long.parseLong(cleanupValue(props.getProperty("jms_queue_name"))); 
    public String getResponse() throws IOException, RuntimeException {
  LOGGER.info("cfg jms_queue_ttl: " +   int sec = 0;
queueTtl.toString());
            byte[]jocApiUri buffer = {};
cleanupValue(props.getProperty("joc_api_url"));
           while (inLOGGER.available() == 0) {
info("cfg joc_api_url: " + jocApiUri);
            controllerId try {= cleanupValue(props.getProperty("controller_id"));
            LOGGER.info("cfg controller_id: " + Thread.sleep(1000controllerId);
            }workflowPath catch= (InterruptedException e) {
    cleanupValue(props.getProperty("workflow_path"));
            LOGGER.errorinfo("", ecfg workflow_path: " + workflowPath);
            username  }
 = cleanupValue(props.getProperty("username"));
           if (sec++pwd == TIMEOUT) { cleanupValue(props.getProperty("password"));
            requestBody = "{\"controllerId\":\"" + throwcontrollerId new RuntimeException("timeout reached");
+ "\",\"orders\":[{\"workflowPath\":\"" + workflowPath
              }
        }+ "\",\"scheduledFor\":\"now\"}],\"auditLog\":{}}";
        buffer} =catch new byte[in.available()];
(IOException e) {
         int bytesRead = inLOGGER.read(buffer);
        return new String(buffer, "ISO-8859-1warn("could not read properties file, use defaults instead.");
     }

    public void disconnect() throwsjmsServerUri Exception {
= DEFAULT_JMS_URI;
           if queueName (socket != null) {
= DEFAULT_QUEUE_NAME;
            jocApiUri  socket.close()= DEFAULT_JOC_API_URL;
        }
    requestBody    if (in != null) {
= DEFAULT_JOC_API_REQUEST_BODY;
            username     in.close()= DEFAULT_USERNAME;
        }
    pwd    if (out != null) {
= DEFAULT_PWD;
            queueTtl = out.close()5000L; 
        }
    }

}

Maven Configuration Example

This example shows the dependency needed dependencies required to build the example above as a Maven project.

Code Block

language	xml
title	Maven Configuration
collapse	true

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>


	<groupId>com.sos-berlin</groupId>
	<artifactId>activeMQ-example</artifactId>
	<version>0.0.1-SNAPSHOT</version>


	<dependencies>
		<dependency>
			<groupId>org.apache.activemq</groupId>
			<artifactId>activemq-all</artifactId>
			<version>5.1315.0</version>
		</dependency>
	</dependencies>
</project>

...

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Key

Introduction

Mode of Operation

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Prerequisites

The `MessageProducer`

Methods

`createConnection(String url)`

`write(String text)`

createSession(Connection connection)

`createDestination(Session session, String queueName)`

`createMessageProducer(Session session, Destination destination)`

`write(String text, MessageProducer producer)`

`close()`

The `SOSProducer` class

The `MessageConsumer`

Methods

`read()`

The `MessageConsumer`

The Methods

`createMessageConsumer(Session session, Destination destination)`

`read(MessageConsumer consumer)`

The `SOSConsumer` class

`connect(String host, int port)`

`disconnect()`

`sendRequest(String command)`

`getResponse()`

`receiveFromQueue()`

Java Class with a `main(String[] args)` method (example `JmsExecute.java`)

The `SOSConsumer` class

Maven Configuration Example

Space shortcuts

Page tree

Page History

Versions Compared

Old Version 3

New Version Current

Key

Introduction

Mode of Operation

Download

Prerequisites

The MessageProducer

Methods

createConnection(String url)

write(String text)

createSession(Connection connection)

createDestination(Session session, String queueName)

createMessageProducer(Session session, Destination destination)

write(String text, MessageProducer producer)

close()

The SOSProducer class

The MessageConsumer

Methods

read()

The MessageConsumer

The Methods

createMessageConsumer(Session session, Destination destination)

read(MessageConsumer consumer)

The SOSConsumer class

connect(String host, int port)

disconnect()

sendRequest(String command)

getResponse()

receiveFromQueue()

Java Class with a main(String[] args) method (example JmsExecute.java)

The SOSConsumer class

Maven Configuration Example

The `MessageProducer`

`createConnection(String url)`

`write(String text)`

`createDestination(Session session, String queueName)`

`createMessageProducer(Session session, Destination destination)`

`write(String text, MessageProducer producer)`

`close()`

The `SOSProducer` class

The `MessageConsumer`

`read()`

The `MessageConsumer`

`createMessageConsumer(Session session, Destination destination)`

`read(MessageConsumer consumer)`

The `SOSConsumer` class

`connect(String host, int port)`

`disconnect()`

`sendRequest(String command)`

`getResponse()`

`receiveFromQueue()`

Java Class with a `main(String[] args)` method (example `JmsExecute.java`)

The `SOSConsumer` class