Apache Camel is a framework that primarily facilitates solving enterprise integration challenges. At its core it can be thought of as a routing engine engine builder. In essence it allows you to connect systems(endpoints) via routes. These routes accept messages which can be of any data type.
The Apache Camel framework also contains a complete set of EIP(Enterprise integration patterns) such as splitter, aggregators, content based routing and so on. Since the framework can be deployed in various standalone in Java applications, in various application servers such as WildFly and Tomcat or on a fully fledged enterprise service bus it can be seen as a integration framework.
To get started with the framework you would need to add it to a project using one of the following methods:
Using the publisher:
producerTemplate.asyncSendBody("direct:myprocedure", massageBody);
Using the "createProducer()" in ManagedCamel to create the producerTemplate.
Some definitions given here are not perfectly accurate, but they will help you understand the code above. Here are a few links for more detailed information :
About the use of AdviceWith and weaveById (Or other ways to trigger routes), have a look at the official apache-camel documentation : see this link
About the use of ProducerTemplate, see the official documentation again : see this link
To really understand what camel is all about : Entreprise Integration Patterns detailed documentation
This particular way of testing is pretty hard to find, even on stack overflow. This is pretty specific but don't hesitate to ask for more details, maybe I'll be able to help.