Load a Apache Camel route at runtime from a file

Question

I am attempting to load an Apache Camel route at runtime from a file. This means

My "route.yaml" file is as follows.

- route:
    from: "timer:yaml?period=3s"
    steps:
      - set-body:
          simple: "Timer fired ${header.CamelTimerCounter} times"
      - to:
          uri: "log:yaml"

I have seen that in the past it was possible to do the following to load a route xml file, but now this cannot be done. For example I see loadRoutesDefinition at Unable to start Camel Routes which are loaded from external XML

InputStream routesXml = new ByteArrayInputStream(routePropertyValue.toString().getBytes());
RoutesDefinition loadedRoutes = camelContext.loadRoutesDefinition(routesXml);
camelContext.addRouteDefinitions(loadedRoutes.getRoutes());

How to do it with the current Apache Camel?

Answer 1

You can also load an XML file from classpath.

import org.apache.camel.CamelContext;
import org.apache.camel.CamelContextAware;
import org.apache.camel.ExtendedCamelContext;
import org.apache.camel.impl.engine.DefaultResourceResolvers;
import org.apache.camel.spi.Resource;
import org.apache.camel.spi.RoutesLoader;
import org.springframework.stereotype.Component;

import javax.annotation.PostConstruct;

@Component
public class RouteLoader implements CamelContextAware {

  private CamelContext camelContext;

  @Override
  public CamelContext getCamelContext() {
    return camelContext;
  }

  @Override
  public void setCamelContext(CamelContext camelContext) {
    this.camelContext = camelContext;
  }

  @PostConstruct
  void loadRoutes() {
    loadRoute("camel-routes.xml");
  }

  private void loadRoute(String name) {
    ExtendedCamelContext extendedCamelContext = camelContext.adapt(ExtendedCamelContext.class);
    RoutesLoader loader = extendedCamelContext.getRoutesLoader();
    try (DefaultResourceResolvers.ClasspathResolver resolver = new DefaultResourceResolvers.ClasspathResolver()) {
      resolver.setCamelContext(camelContext);
      Resource resource = resolver.resolve("classpath:" + name);
      loader.loadRoutes(resource);
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
  }

}