Evaluate Jms Destination Dynamically from header using JmsSendingMessageHandler-CodePudding

I am trying to send message using JmsSendingMessageHandler but could not find a method which would fetch destination value from header something like messageHandler.setDestinationExpressionString("headers['destination_name']") ?

@MessagingGateway
public interface OutboundMessageGateway {

    @Gateway(requestChannel = "outMessageChannel")
    void sendMessage(Message<?> message);

}

@Bean
@ServiceActivator(inputChannel = "outMessageChannel" )
private MessageHandler jmsOutboundHandler() {
        JmsSendingMessageHandler messageHandler = new JmsSendingMessageHandler(new JmsTemplate(connectionFactory());
        messageHandler.setDestinationExpressionString("headers['destination_name']"); // not available
        return messageHandler;
    }

any solution ? I want to fetch destination dynamically from header I am passing with Message<?>

CodePudding user response：

There is no API like that JmsSendingMessageHandler.setDestinationExpressionString(). Not sure why your IDE doesn't suggest you that you are on a wrong way, but there is other choice. My one shows this:

If you are really sure that you set that destination_name upstream, then you indeed can use that setDestinationExpression(Expression) API and like this:

handler.setDestinationExpression(new SpelExpressionParser().parseExpression("headers['destination_name']"));

Another, more Java-way is like this:

handler.setDestinationExpression(new FunctionExpression<Message<?>>(m -> m.getHeaders().get("destination_name")));

I think we can add that setDestinationExpressionString() anyway, if you insist and can contribute such a fix back to the framework: https://github.com/spring-projects/spring-integration/blob/main/CONTRIBUTING.adoc