What is avalon?
Apache's Avalon is a complete development platform for component programming (COPs), including core frameworks, tools, components, and containers. By using key design patterns, such as reverse control mode (IOC) and separation consideration (SOC), Avalon achieves some advantages of the traditional OOP framework:
There is no executive, J2EE or web environment embedded container for lifecycle management and easy-to-use API component metadata framework and tool service.
In COP, reusable components can be combined into the container to provide an application module. Modules can be used in turn to create what you need, from customer desktop applications, to FTP servers, to web services, and more. Avalon offers a variety of basic components and default application modules to help you quickly build your own application solution.
Avalon's goal is:
Provide a stable COP development platform to create a series of rich client components API extremely default to develop a complete container solution to explore and extend COP development practices
Avalon's products and subprojects
(1) Container: Merlin
Merlin is Avalon's container reference implementation, providing full support for managing components-based complex systems. Merlin uses components to make simple or composite components automatic assembly and development easily.
(2) framework
Avalon's component model is a combined classic interface to define the objects exchanged between the container and components. The requirements of the components in the container are used and the component-related meta-information description. Interfaces and default implementations are described by Avalon's framework package; meta information descriptions and related tools are included in the META package.
Avalon's component model includes:
Avalon Framework API and its implementation: consisting of interfaces that define common application component relationships; use best practical modes, independent lightweight simple implementations of universal components. Avalon Meta: Avalon Meta Model Defines the Function Standards for Components Types and Services. Type definitions include information on the dependence information of the development and running, and the service of the component type. Avalon Utilities: A group of shared tools that support default attribute management, environment variable schemes, exception reports, and parameterized MAP implementation (used in the Repository package). Avalon repository: Combined with Avalon projects and Apache Directory projects while providing intelligent Bootstrapping, resource replication, and object management frameworks. Avalon logkit: A perfect log frame as a Avalon component (similar log4j). Most Avalon containers use it as the default log implementation.
(3) Component library
Avalon's component library includes:
CornerStone Collection: A set of components that can be used for simple applications. These components are typically a separate component representing the infrastructure block. Excalibur Utilities: A set of service tools, including internationalization, configuration tools, thread management, log subsystems, and more. Third party component library.
