骆驼路线以向主题发布消息并从队列中接收消息

Question

For some test client I am using yopa library that imitate local aws . In order to publish message to the topic and then recieve it to the queue I do like this

    AmazonSQS amazonSQSClient = AmazonSQSClientBuilder.standard()
            .withCredentials(new AWSCredentialsProvider() {
                @Override
                public AWSCredentials getCredentials() { return null; }

                @Override
                public void refresh() { }
            })
            .withEndpointConfiguration(new EndpointConfiguration("http://localhost:47195", "yopa-local")) // local stub
            .build();
    AmazonSNS amazonSNSClient = AmazonSNSClientBuilder.standard()
            .withCredentials(new AWSCredentialsProvider() {
                @Override
                public AWSCredentials getCredentials() { return null; }

                @Override
                public void refresh() { }
            })
            .withEndpointConfiguration(new EndpointConfiguration("http://localhost:47196", "yopa-local")) // local stub
            .build();
    amazonSNSClient.publish("arn:aws:sns:yopa-local:000000000000:test-topic-with-subscriptions",
            "This is my message");
    ReceiveMessageResult message = 
            amazonSQSClient.receiveMessage("http://localhost:47195/queue/test-subscribed-queue-standard");
    System.out.println("Number of recievied messages: " + message.getMessages().get(0));

It works fine.

But how to implement that flow using apache camel and spring ?

When I create routes like this

<routeContext id="myRoute" xmlns="http://camel.apache.org/schema/spring">
    <route id="publish.route">
        <from uri="bean:snsPublisher?method=publish({{sns.topic}}, ${body})"/>
        <to uri="arn:aws:sns:yopa-local:000000000000:test-topic-with-subscriptions"/>
        <onException redeliveryPolicyRef="redeliveryPolicy">
            <exception>java.lang.Exception</exception>
            <handled>
                <constant>{{camel.handle.exception}}</constant>
            </handled>
        </onException>
    </route>
</routeContext>

With publisher bean

public class SnsPublisher extends SnsClient implements IPublisher<String> {
    @Override
    public void publish(String topic, String message) {
        try {
            PublishResult publishResult = getAmazonSNSClient().publish("arn:aws:sns:yopa-local:000000000000:test-topic-with-subscriptions", message);
        } catch (AmazonSNSException exception) {
        }
    }
}

( SnsClient is class that provides the same AmazonSNS object as in previous example.)

Even at start of the application I get

Caused by: org.apache.camel.ResolveEndpointFailedException: 
Failed to resolve endpoint: arn://aws:sns:yopa-local:000000000000:test-topic-with-subscriptions due to: No component found with scheme: arn

org.apache.camel.RuntimeCamelException: org.apache.camel.FailedToCreateRouteException: 
Failed to create route publish.route at: >>> To[arn:aws:sns:yopa-local:000000000000:test-topic with-subscriptions] <<< in route: Route(publish.route [[From[bean:snsPublisher... because of Failed to resolve endpoint: arn://aws:sns:yopa-local:000000000000:test-topic-with-subscriptions due to: No component found with scheme: arn

Answer 1

No component found with scheme: arn

this says "arn" is not a component name that camel can recognise.

Camel's url starts with name of one camel component, which should defined first.

For example, if you connect to activemq, you should implement a JmsComponent or ActiveMQComponent, with a name,let's say, "amq", then you can connect to "amq:xxxx" in camel uri.

I never used aws, so I can't give your very specific advice. What I can tell you is that you need to implement a "arn" component, maybe it exists in some third-party library, or you need to write your own camel component class.