4.6.3. 修改应用程序代码以使用系统属性替代

将硬编码的 @ActivationConfigProperty@Resource 注释值替换为新定义的系统属性。以下是如何更改 helloworld-mdb quickstart 以使用新定义的系统属性替换的示例:

  1. 更改 HelloWorldQueueMDB 类中的 @ActivationConfigProperty destination 属性值,以使用 system 属性替换。@MessageDriven 注释现在应如下所示:

    HelloWorldQueueMDB 代码示例

    @MessageDriven(name = "HelloWorldQueueMDB", activationConfig = {
        @ActivationConfigProperty(propertyName = "destinationLookup", propertyValue = "${property.helloworldmdb.queue}"),
        @ActivationConfigProperty(propertyName = "destinationType", propertyValue = "javax.jms.Queue"),
        @ActivationConfigProperty(propertyName = "acknowledgeMode", propertyValue = "Auto-acknowledge") })

  2. 更改 HelloWorldTopicMDB 类中的 @ActivationConfigProperty 目标 属性值,以使用 system 属性替换。@MessageDriven 注释现在应如下所示:

    HelloWorldTopicMDB Code Example

    @MessageDriven(name = "HelloWorldQTopicMDB", activationConfig = {
        @ActivationConfigProperty(propertyName = "destinationLookup", propertyValue = "${property.helloworldmdb.topic}"),
        @ActivationConfigProperty(propertyName = "destinationType", propertyValue = "javax.jms.Topic"),
        @ActivationConfigProperty(propertyName = "acknowledgeMode", propertyValue = "Auto-acknowledge") })

  3. 更改 HelloWorldMDBServletClient 类中的 @Resource 注释,以使用系统属性替换。现在,代码应该类似如下:

    HelloWorldMDBServletClient Code 示例

    /**
     * Definition of the two Jakarta Messaging Service destinations used by the quickstart
     * (one queue and one topic).
     */
     @JMSDestinationDefinitions(
         value = {
             @JMSDestinationDefinition(
                 name = "java:/${property.helloworldmdb.queue}",
                 interfaceName = "javax.jms.Queue",
                 destinationName = "HelloWorldMDBQueue"
             ),
             @JMSDestinationDefinition(
                 name = "java:/${property.helloworldmdb.topic}",
                 interfaceName = "javax.jms.Topic",
                 destinationName = "HelloWorldMDBTopic"
             )
         })
    /**
     * <p>
     * A simple servlet 3 as client that sends several messages to a queue or a topic.
     * </p>
     *
     * <p>
     * The servlet is registered and mapped to /HelloWorldMDBServletClient using the {@linkplain WebServlet
     * @HttpServlet}.
     * </p>
     *
     * @author Serge Pagop (spagop@redhat.com)
     *
     */
    @WebServlet("/HelloWorldMDBServletClient")
    public class HelloWorldMDBServletClient extends HttpServlet {
    
        private static final long serialVersionUID = -8314035702649252239L;
    
        private static final int MSG_COUNT = 5;
    
        @Inject
        private JMSContext context;
    
        @Resource(lookup = "${property.helloworldmdb.queue}")
        private Queue queue;
    
        @Resource(lookup = "${property.helloworldmdb.topic}")
        private Topic topic;
    
      <!-- Remainder of code can be found in the `helloworld-mdb-propertysubstitution` quickstart. -->

  4. 修改 activemq-jms.xml 文件,以使用系统属性替换值。

    .activemq-jms.xml 文件示例

    <?xml version="1.0" encoding="UTF-8"?>
    <messaging-deployment xmlns="urn:jboss:messaging-activemq-deployment:1.0">
        <server>
             <jms-destinations>
                <jms-queue name="HELLOWORLDMDBQueue">
                    <entry name="${property.helloworldmdb.queue}"/>
                </jms-queue>
                <jms-topic name="HELLOWORLDMDBTopic">
                    <entry name="${property.helloworldmdb.topic}"/>
                </jms-topic>
            </jms-destinations>
        </server>
    </messaging-deployment>

  5. 部署应用。应用现在将系统属性指定的值用于 @Resource 和 @ ActivationConfigProperty 属性值。