camel create routes dynamically

Apache camel, create routes dynamically

Create camel routes dynamically

In this entry we'll create a camel route dynamically.
The route uses the camel-mail component that permits to connect to pop/imap/smtp mailboxs.

Dependencies

We use the version 2.9.0 of camel.
maven

  <dependency>
   <groupId>org.apache.camel</groupId>
   <artifactId>camel-core</artifactId>
   <version>2.9.0</version>
  </dependency>
  <dependency>
   <groupId>org.apache.camel</groupId>
   <artifactId>camel-mail</artifactId>
   <version>2.9.0</version>
  </dependency>

ivy

 <dependency org="org.apache.camel" name="camel-core" rev="2.9.0"/>
 <dependency org="org.apache.camel" name="camel-mail" rev="2.9.0"/>

RouteBuilder

In order to create a new Route it is necessary to create a class that extends RouteBuilder.
After you have to implement the method configure() that permits to configure your route.
Example for an imap email route

 public class MailRouteBuilder extends RouteBuilder {
 
  private String login;
  private String password;
  private String host;

  public MailRouteBuilder(String login,String password,String host){
   this.login=login;
   this.password=password;
   this.host=host;
  }


  @Override
  public void configure() throws Exception {
   fromUri=String.format("imap://%s?username=%s&password=%s",host,login,password);
   from(fromUri).to("mock:myMock");
  }
 }

If you use a processor, don't forget to assign an id to the bean inside the camel spring context ex:

 from(fromUri).processRef("imapProcessor").to("mock:myMock");

 
 <bean id="imapProcessor" class="myPackage.MyProcessor" />

Ok, now we have a builder for the new route in a very easy way.
Now it is necessary to create a new spring bean that implements CamelContextAware. If you use spring and annotation you can configure in a very easy way with the @Service annotation:

 @Service
 public class CamelRouteManager implements CamelContextAware { ...
  

If you don't use the annotation, so you have to edit the camel spring context:

 <bean id="camelRouteManager" class="myPackage.CamelRouteManager" />

The implementation of CamelContextAware need to implement the getter/setter for the camel context. It means you have to provide a camelContext field.

 protected CamelContext camelContext;

 public CamelContext getCamelContext() {
  return camelContext;
 }

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

 }

Now we can create a method named addMailRoute that creates a new imap route:

 public void addMailRoute(String login,String password,String host){
  MailRouteBuilder mailRouteBuilder=new MailRouteBuilder(login,password,host);
  this.camelContext.addRoutes(mailRouteBuilder); 
 }

If all is ok the route should start automatically.
Ok, but if I want to remove, stop or suspend a route, how can I do ?
Very easy, you have just to use:

camelContext.removeRoute(String routeId)

camelContext.stopRoute(String routeId)

camelContext.suspendRoute(String routeId)

Take care, for remove a route it is necessary to stop it before.
Ok, how can I retrieve the id of the route created dynamically ?
Just have to retrieve the routeDefinition object, go back in the MailRouteBuilder class:

 private RouteDefinition routeDefinition;

 
 @Override
 public void configure() throws Exception {
  fromUri=String.format("imap://%s?username=%s&password=%s",host,login,password);
  routeDefinition=from(fromUri).to("mock:myMock");
 }

 public RouteDefinition getRouteDefinition() {
  return routeDefinition;
 }

 

Now retrieve the routeDefinition object and extract the id in the CamelRouteManager class:

 public String addMailRoute(String login,String password,String host){
  MailRouteBuilder mailRouteBuilder=new MailRouteBuilder(login,password,host);
  this.camelContext.addRoutes(mailRouteBuilder);
  return mailRouteBuilder.getRouteDefinition().getId(); 
 }

It is also possible to create several routes in one shot. You can adapt the code to have a list of routeDefinition instead of a simple String
Now all is done, you can enjoy all your created routes.

apache camel official site

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