ka-event is a simple annotation-driven event-listener Framework for Java 1.5+, with Spring and Guice Support. Ka-Event is based on the concepts of elf but modernized to fit in a Java 1.5+ / Spring environment. Annotations and Generics is used to configure events minimizing the configuration effort for Java Developer.
Both XML and programmatically configuration are supported. Look at src/example/java.
But most of all it is easy to use.
- Commons
- Core
- AspectJ
- Spring
- Guice
- OSGi
Using the standard listener pattern which comes with many of the core Java API classes, where every class handles its own listener registers and are responsible for invoking the listener method on the listeners might not be the best solution in many situations.
Some cons with this approach may be:
- Listener registry code duplicated
- Listener invocation code duplicated
- Object will be tightly coupled.
- The over all object graph might be hard to manage when hundred or thousands of objects is interconnected in a gigantic web.
- Invocation is usually synchronous.
Some pros with this approach
- Centralized registers and invocation code.
- Run-time choice of synchronous or asynchronous invocation.
- Loose coupling possible through channels.
- Easy to manage, one object to inspect the Event Dispatcher.
- XML or Programmatic Configuration.
- Channels.
- Choice of synchronous or asynchronoues invocation at runtime.
- Annotation driven configuration.
- Event Filtering.
- Extendable
- Scans classpath for Event Classes.
- Method Resolving, allowing multiple methods in Event Listener Interface.
- Register Listeners automatically by annotations.
- Ka-Event Guice Module
- Configure environment with Guice
- Creates channels using Guice.
- Registers Listeners automatically when annotated.
- Spring XML Namespace.
- Post Bean Processor to register annotated listeners automatically.
- Fire On Commit
- Create Channels from Prototype.