Chapter 4. Remoting between Flex and POJOs
Among all its features, remoting between a Flash player and a Java server could qualify as the central pillar of BlazeDS. Back in Chapter 2, you were made aware of the fundamentals of remoting through a naïve example. In this chapter, you will leap ahead by learning the intricate details of remoting. You will be exposed to the classes, components, modules, and formats that make up the truss that supports this feature.
While Flex and AIR are considered as one side of the pipe, a Java object on the server constitutes the other end. Java objects can be of many types, some of which only respect the Java language contract and some of which that extend specific classes or implement special interfaces. They can exist in a plain vanilla JVM (Java virtual machine) instance or they can be managed within a special container. In this chapter, I talk exclusively about the simple plain Java objects, which are often commonly termed as Plain Old Java Objects, or POJO(s) for short. Read the note on POJOs to learn more about them.
POJOsPOJO, which stands for Plain Old Java Object, was coined by Martin Fowler, Rebecca Parsons and Josh MacKenzie in September 2000. A POJO represents a simple Java class that does not extend a specific class or implement a special interface, or is annotated by a special piece of metadata. Sometimes, though, the definition of a POJO can be a little relaxed and may include simple objects that may be decorated by certain annotations. The term POJO also implies an alternative Java object as compared to a managed and special object like an EJB (Enterprise Java Bean). |
A good start into a detailed topic is always by viewing it from a high-level perspective, and that's exactly what is coming next.