Apache Camel and the use of Scala DSL

September 2013

Apache Camel

Apache Camel is an open source integration framework that provides Java based implementations for different enterprise integration patterns. Enterprise integration patterns aim at providing a reliable solution to the common integration problems. Implementing enterprise integration patterns can be a challenge due to their complexity. Apache Camel makes it easier for the developers to implement the integration patterns because it wraps the complexity from the user and exposes APIs to implement the patterns.

Following is a snapshot of top features of Apache Camel.

  • Implementations of common Enterprise Integration Patterns
  • A replaceable container
  • Developer friendly DSL
  • Scalability primitives are also built in.

What Is Scala?

Scala is perhaps one of the best features offered by Apache Camel. It is one of the key contributors to the phenomenal popularity of Apache Camel.

Scala is basically a general purpose programming language that is so designed that you will be able to solve a lot of complex programs in a format that is easy to understand and process. When it comes to building routes, it is the Scala syntax that makes programming much more efficient. Scala was first founded in 2003 and it was created by Martin Odersky. It has undergone a lot of developments and changes and today it is regarded as a mature open space programming language that is a preferred choice among a lot of web developers. The main reason that make Scala DSL popular has to be the fact that it offers you an exciting and rich blend of object oriented and functional programming simultaneously.

Differences with Java DSL

When you are creating a new Camel Scala project, you can make use of root builder class just like you do in java DSL. You can extend these classes and make your own routes; however when you do so, there are going to be some differences in the way you work.

Unlike java DSL, you do not need to override the configure() method. When you are setting the route, you do not need “from (uri)” rather, you can simply start it by typing URI. Further, it is to be noted that “->” is simply a substitute for “to”. It is easy to overwrite a lot of different operators such as “+”. Not just overwrite, you have the option of defining a new operator too and this makes coding much simpler and efficient. Even when it comes to using process and beans, Scala DSL offers a lot of convenience as it cuts down the extra code and eliminates a lot of useless clutter. One major drawback with Scala DSL has to be the fact that not all the different enterprise integration patters can be implemented in Scala; however, with the recent developments that are taking place, it may soon become a possibility. Hence, all those who are looking for a framework that can simplify the task of merging and integrating different systems into a single unit seamlessly can benefit immensely from the use of Scala DSL in Apache Camel. All those who have been opting for its use have managed to create compact codes that are not only easy to create, but debugging and maintenance is simple too.