Apache Camel如何从路由动态添加/删除端点

Question

I am trying to get familiar with EIP and Apache Camel and I have a use case that I am not quite sure how can be expressed or implemented using Camel

Use case:

Imagine you have designed an integration solution that takes files from an ftp, does some processing and uploads it to a queue. You chose Apache Camel to implement this solution and your route in Java DSL looks something like this:

 from("ftp://user@hostname/directoryname")
   .process(new Processor() {
              public void process(Exchange exchange) throws Exception
              {
                //my fantastic prosessing goes here
              }
 }).to("jms:queue:queueName");

the route could be way more complex than this, but it doesn't matter here. Imagine your solution is such a spectacular success that there's a plan to implement a service where anyone could add his ftp server and get the files processed and uploaded to the queue. So what you want is

1. (Flexibility) Being able to dynamically add/remove servers from your app
2. (Scaling) Being able to handle potentially large number of such servers

Let's forget about #2 and focus on Flexibility part.

So the question is, I suppose:

How to dynamically (at runtime) add/remove endpoints to/from Apache Camel route?

What I considered so far:

First, I admit I am not that familiar with Integration Patterns, but just scanning the catalogue, the only thing that kind of could fit the bill is the Content Enricher . It can take a message and just go off to somewhere else and bring sth else. So I was thinking if someone adds an ftp server, the connection details could be encapsulated in the message and a Content Enricher could then connect to that ftp server and fetch files and push it further through the route.... so it would effectively be a Content Enricher capable of connecting to multiple ftp servers.... That kind of sound wrong. First I don't think this is the intention behind that pattern and secondly since there's ftp Component in Camel, I should somehow be able to use it in that scenario

The second approach would be to break the route into two like using the vm component, like this:

 from("ftp://user@hostname/directoryname").to("vm:internalQ");
 from("vm:internalQ")
   .process(new Processor() {
              public void process(Exchange exchange) throws Exception
              {
                //my fantastic prosessing goes here
              }
 }).to("jms:queue:queueName");

so now, I can create many routes with ftp endpoints that write to that internal queue so it can be picked up. Adding route dynamically to CamelContext seems to be possible ( Add camel route at runtime in Java ). Is that the way to go? Or am I just trying to use Camel in a way that it was not designed to?

Answer 1

You can dynamically add routes to your CamelContext :

MyRouteBuilder trb = new MyRouteBuilder(servletEndpoint, mockEndpoint);
camelContext.addRoutes(trb);

And MyRouteBuilder:

MyRouteBuilder(Endpoint servletEndpointStart, MockEndpoint mockEndpointEnd, String allowedParameters){
        this._servletEndpoint = servletEndpointStart;
        this._mockEndpoint = mockEndpointEnd;
    }

    @Override
    public void configure() throws Exception {
        from(this._servletEndpoint)
        .id(TESTING_ROUTE_NAME)
        .process(new Processor(){ // some processor })
        .to(_mockEndpoint);
    }

You can also modify the route, but you will need to restart it, in order to work properly, checkout how it is done in: org.apache.camel.model.RouteDefinition.adviceWith(ModelCamelContext, RouteBuilder)