iamp-mq-component

The mq-component is a reusable library (.jar) responsible for bridging applications and queues (IBM MQ).

All the communications between applications and the MQ/s should occur through this component; it provides a simple interface of communication to read, write and listen from a queue.

Configuration

Create an XML file named mq-component.xml in your classpath (i.e. /src/main/resources), and copy the following example:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

    <bean id="MQ1"
    class="ca.bc.gov.iamp.mq.component.properties.MQConfigurationProperties">
        <property name="host" value="localhost" />
        <property name="port" value="1414" />
        <property name="channel" value="DEV.APP.SVRCONN" />
        <property name="queueManager" value="QM2" />
        <property name="appUser" value="APP" />
        <property name="appPassword" value="app" />
        <property name="queueName" value="DEV.QUEUE.1" />
    </bean>

    <bean id="MQ2"
    class="ca.bc.gov.iamp.mq.component.properties.MQConfigurationProperties">
        <property name="host" value="localhost" />
        <property name="port" value="1414" />
        <property name="channel" value="DEV.APP.SVRCONN" />
        <property name="queueManager" value="QM3" />
        <property name="appUser" value="APP" />
        <property name="appPassword" value="app" />
        <property name="queueName" value="DEV.QUEUE.1" />
    </bean>

</beans>

Each new MQ added to the configuration is a new <bean id=”MQx” /> added to the XML file; each MQ must contain all properties:

Usage examples

Reading from a queue

Steps:

1. Declare and autowire an MQComponent object;
2. Use the connect(String mq) method, passing the bean id from mq-component.xml as input string;
3. Use the consumeText() method to read the next queued message in the queue.

Code:

@Autowired
private MQComponent mq1;

@PostConstruct
public void init() throws JMSException, MQConnectionException {
    mq1.connect("MQ1");
}

public String consume() {
String receivedMessage = null;
    try {
        receivedMessage = mq2.consumeText();
    } catch (MQConnectionException | MQCommunicationException e) {
        /* log error here */
    }
    return receivedMessage;
}

Writing to a queue

Steps:

1. Declare and autowire an MQComponent object.
2. Use the connect(String mq) method, passing the bean id from mq-component.xml as input string.
3. Use the send(String message) method to send a string message to the queue.

Code:

@Autowired
private MQComponent mq2;

@PostConstruct
public void init() throws JMSException, MQConnectionException {
    mq2.connect("MQ2");
}

public String send() {
String message = "Your message";
    TextMessage sampleMessage = null;
    try {
        sampleMessage = mq2.send(message);
    } catch (MQConnectionException | MQCommunicationException e) {
        /* log error here */
    }
    return sampleMessage.toString();
}

Listening to a queue

Steps:

1. Create a new class implementing the class MessageListener from JMS library;
2. Declare and autowire an MQComponentListener object;
3. Use the connect(String mq) method, passing the bean id from mq-component.xml as input string;
4. Use the listen() method passing this as input.
5. Process the messages in the onMessage(Message message) method.

Code:

public class CustomListener implements MessageListener {

    @Autowired
    MQComponentListener mqComponentListener;

    @PostConstruct
    public void init() {
        try {
            mqComponentListener.connect("MQ1");
            mqComponentListener.listen(this);
        } catch (MQConnectionException | MQCommunicationException e | JMSException e) {
            /* log error here */
        }
    }

    @Override
    public void onMessage(Message message) {
        /* process message here */
    }

}