Why Apache Axis2: the Future of Web Services Paul Fremantle WSO2 Inc

Why Apache Axis2: The Future of Web Services Paul Fremantle WSO2 Inc.

Paul Fremantle – Why Apache Axis2 : The Future of Web Services Page 1 Colorado Software Summit: October 22 – 27, 2006 © Copyright 2006, WSO2, Inc. About Me ... Apache Software Foundation - Member Apache Web Services - PMC Member Apache Axis2, Axiom – Committer, Release Manager. Apache Synapse - Committer Member of W3C Working Group for WS- Addressing, WSDL 2.0 Working with WSO2 on Apache Axis2, Apache Axiom, Apache Synapse and WSO2 Tungsten.

Introduction and Motivation

The “big picture”

Key Features of Apache Axis2 High Performance XML Processing Model Extensible Messaging Engine Pluggable Module Architecture Improved Deployment Model New Client API Optional Pluggable Data Binding REST Support Other Improvements

Summary and Conclusion

Paul Fremantle – Why Apache Axis2 : The Future of Web Services Page 3 Colorado Software Summit: October 22 – 27, 2006 © Copyright 2006, WSO2, Inc. A Quick Look At SOAP Stacks First Generation :: Apache SOAP

First Apache driven SOAP stack SOAP carries RPC requests & responses in XML form Apache SOAP Based on DOM Slower and memory intensive

Based on SAX Introduced the handler architecture for SOAP stacks Faster and better than Apache SOAP Wide Industry Acceptance Integrated to major application servers like WebSphere and JBoss Highly Interoperable

Limitations of handler architecture Inherent request/response nature

Need for more document centric interactions Need for more asynchrony

Need to support new specifications like WSDL 2.0 and various QoS protocols WS-A, WS-RM, WS-SX

• Performance – Parsers, Optimizing based on use • Ease of use – Deployment of new capabilities, service deployment

C lie n t A P I Server API

Engine Transports

> > > Phases > > >

R epository Core

Services Repository

Modules Axiom

STAX

New XML Infoset Representation Deferred building StAX integrated Extensible Messaging Engine Pluggable Module Architecture Improved Deployment Model New Client API Optional Pluggable Data Binding REST Support

New XML Info-set Representation

Known as AXIOM (Axis Object Model) Yet another XML object model? API is more like a simplified DOM Fundamental Difference ? Objects are made “on demand” using a pull model Allows direct access to the underlying pull stream with or without building the tree Support for storing binary values Support for multiple implementations

Build object model to here h = envelope.getHeader(securityQName) ... MEGABYTES OF DATA HERE ... ...and then you can do body = envelope.getBody();

reader = body.getXMLStreamReader();

while (reader.hasNext()) { ... }

API also provides a StAX parser interface at any element Allows the event based navigation of the OM tree.

New XML Infoset Representation

AXIOM

O M E le m e n t.g e tC h ild re n () e tc

S T A X O M B u ild e r. API getDocum entElem ent() O M Element.serialize() Read (tre e )

P u ll s tr e a m

Push stream

S A X O M B u ild e r. getDocum entElem ent() OMElement. getXM LStream R eader() AXIOM O M Factory.createOM Elem ent()

P u ll s tr e a m

Push stream

API Write (tree)

Paul Fremantle – Why Apache Axis2 : The Future of Web Services Page 14

Faster and Easier Deployment Service Archive files (.aar files) A collection of resources needed for a service Includes Service implementation Handlers (optional) Service descriptor (services.xml)

Improved Deployment Model (Continued)

Hot Deployment “Drop in” deployment Uploaded through File system Axis2 web application

The link between Axis2 and your service application Either a simple “POJO” MR Calls a Java object Or code-generated from WSDL Part of the WSDL2Java

WSDL2Java

Takes a WSDL Generates either client or server components Or both! Plus an Ant build script Plus the Services.xml Java2WSDL Takes a Java class and generates WSDL for you Used when dealing with Java clients

Generates a custom Message Receiver Plus a “skeleton” You fill in the code

How to provide data binding support ? Use a well established framework Avoid reinventing the wheel! Flexible Adds more functionality e.g. XMLBeans supports the complete XML Schema Features an API that can bind to another data binding framework

Paul Fremantle – Why Apache Axis2 : The Future of Web Servi