Welcome to Apache Axis2/Java

Why Apache Axis2:

A new architecture for Axis2 was introduced during the August 2004 Summit in Colombo, Sri Lanka. The new architecture on which Axis2 is based on is more flexible, efficient and configurable in comparison to Axis1.x architecture. Some well established concepts from Axis 1.x, like handlers etc., have been preserved in the new architecture.

Apache Axis2 not only supports SOAP 1.1 and SOAP 1.2, but it also has integrated support for the widely popular REST style of Web services. The same business logic implementation can offer both a WS-* style interface as well as a REST/POX style interface simultaneously.

Apache Axis2 over time has expanded to contemporary JSON (JavaScript Object Notation) web services, and that area is where new development is occuring. In addition to GSON for the Java serialization/deserialization of JSON, Moshi is now supported since GSON development has largely ceased.

Apache Axis2 is more efficient, more modular and more XML-oriented / JSON-orientated than the older version. It is carefully designed to support the easy addition of plug-in "modules" that extend their functionality for features such as security and reliability. The Modules currently available or under development include:

• WS-Security - Supported by Apache Rampart
• WS-Addressing -Module included as part of Axis2 core

Apache Axis2 is built on Apache AXIOM, a new high performant, pull-based XML object model - however for JSON based web services, Moshi (or GSON) takes its place and largely follows the same pull-based concepts.

Axis2 comes with many new features, enhancements and industry specification implementations. The key features offered are as follows:

• Speed - Axis2 uses its own object model and StAX (Streaming API for XML) parsing to achieve significantly greater speed than earlier versions of Apache Axis.

• Low memory foot print- Axis2 was designed ground-up keeping low memory foot print in mind.

• AXIOM - Axis2 comes with its own light-weight object model, AXIOM, for message processing which is extensible, highly performant and is developer convenient.

• Hot Deployment - Axis2 is equipped with the capability of deploying Web services and handlers while the system is up and running. In other words, new services can be added to the system without having to shut down the server. Simply drop the required Web service archive into the services directory in the repository, and the deployment model will automatically deploy the service and make it available for use.

• Asynchronous Web services - Axis2 now supports asynchronous Web services and asynchronous Web services invocation using non-blocking clients and transports.

• MEP Support - Axis2 now comes handy with the flexibility to support Message Exchange Patterns (MEPs) with in-built support for basic MEPs defined in WSDL 2.0.

• Flexibility - The Axis2 architecture gives the developer complete freedom to insert extensions into the engine for custom header processing, system management, and anything else you can imagine.

• Stability - Axis2 defines a set of published interfaces which change relatively slowly compared to the rest of Axis.

• Component-oriented Deployment - You can easily define reusable networks of Handlers to implement common patterns of processing for your applications, or to distribute to partners.

• Transport Framework - We have a clean and simple abstraction for integrating and using Transports (i.e., senders and listeners for SOAP over various protocols such as SMTP, FTP, message-oriented middleware, etc), and the core of the engine is completely transport-independent.

• WSDL support - Axis2 supports the Web Service Description Language, version 1.1 and 2.0, which allows you to easily build stubs to access remote services, and also to automatically export machine-readable descriptions of your deployed services from Axis2.

• JSON support - Axis2 supports the creation of Web Services using JavaScript Object Notation, with GSON and Moshi, which allows you to easily build POJO based services that receive and return JSON.

• Composition and Extensibility - Modules and phases improve support for composability and extensibility. Modules support composability and can also support new WS-* specifications in a simple and clean manner. They are however not hot deployable as they change the overall behavior of the system.

We hope you enjoy using Axis2. Please note that this is an open-source effort. If you feel the code could use new features or fixes, or the documentation can be improved, please get involved and lend us a hand! The Axis developer community welcomes your participation.

Let us know what you think! Send your feedback on Axis2 to "java-user@axis.apache.org". Make sure to prefix the subject of the mail with [Axis2].