如何从属性文件定义注释的字段值

Question

I'm playing with spring and activemq and use the following method to receive messages from message broker:

@JmsListener(destination = "sample.queue")
public void receiveQueue(String text) {
    System.out.println(text);
}

I just thought it would be nice to be able to configure destination from my application.properties . Is there any way to do that ?

Answer 1

Ok, I found the way. Suppose message-consumer.destination property from application.properties defines the desired destination, then it would be as simple as this:

@JmsListener(destination = "${message-consumer.destination}")
public void receiveQueue(String text) {
    System.out.println(text);
}

Below are my old thoughts on how to externalize queue destination:

Here is the message consumer.

@Component
public class Consumer implements MessageListener {

    @Override
    public void onMessage(Message message) {

    }
}

Here is the jms configuration:

@Configuration
@EnableJms
public class JmsConfiguration implements JmsListenerConfigurer {

    @Value("${message-consumer.destination}")
    private String destination;

    @Inject
    private MessageListener messageListener;

    @Override
    public void configureJmsListeners(JmsListenerEndpointRegistrar registrar) {
        SimpleJmsListenerEndpoint endpoint = new SimpleJmsListenerEndpoint();
        endpoint.setId("audit.logging");
        endpoint.setDestination(destination);
        endpoint.setMessageListener(messageListener);
        registrar.registerEndpoint(endpoint);
    }

Answer 2

I don't think you can add a variable to this but even if you can I think a better solution is to use a DestinationResolver as this is what the destination is used for.

There is some explanation of this in the Spring documentation .

Answer 3

It's possible by reading the properties file at class level:

Create a file 'my.properties' in your resources dir:

destination = sample.queue

And a wrapper class:

public class MyProperties {

    private static final RespourceBundle BUNDLE = RespourceBundle.getBundle("/my.properties");

    public static String destination() {
        return BUNDLE.getProperty("destination");
    }
}

Then change your code like this:

@JmsListener(destination = MyProperties.destination())
public void receiveQueue(String text) {
    System.out.println(text);
}

Haven't tested it, but I think that should work.

EDIT: I'm sure I've used constants in annotations before. Maybe this static method is causing the problem. Try this:

public class MyProperties {

    private static final RespourceBundle BUNDLE = RespourceBundle.getBundle("/my.properties");

    public static final String DESTINATION = BUNDLE.getProperty("destination");

}

and:

@JmsListener(destination = MyProperties.DESTINATION)
public void receiveQueue(String text) {
    System.out.println(text);
}

EDIT: one last attempt

public class MyProperties {

    private static final RespourceBundle BUNDLE = RespourceBundle.getBundle("/my.properties");

    public static final String DESTINATION;

    static {
        DESTINATION = BUNDLE.getProperty("destination");
    }

}