Apache Camel is a Java framework that lets you implement the standard enterprise integration patterns in a few lines of code. With a concise but sophisticated DSL you snap integration logic into your app, Lego-style, using Java, XML, or Scala. Camel supports over 80 common transports such as HTTP, REST, JMS, and Web Services.
Camel in Action is a Camel tutorial full of small examples showing how to work with the integration patterns. It starts with core concepts like sending, receiving, routing, and transforming data.