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From "Chris Haddad" <>
Subject Re: Axis's Architecture
Date Fri, 26 Mar 2004 17:05:53 GMT

hi vivek - 

transport, global, and service define execution scope.   handlers attached to the service
chain will only execute for web services requests targetting a specific service.  global handlers
will always be executed, and transport handlers are only executed if a message is recieved
by a specific transport listener.

In regards to the application server integration with Axis.  Axis is deployed as a servlet
inside the WAR file.  the app server passes control to the Axis servlet, the servlet invokes
handlers then loads the service agent (which in your use case is an EJB).  the EJB performs
it's work and returns control to the Axis servlet. 

Philosophically, i think EJB's should not be directly exposed as a web service but rather
wrapped behind a stateless session bean. exposing the EJB directly leads to a tightly coupled

As for resources beyond the Axis docs and sources..... the following presentation may be helpful

lead author of O'reillys "Programming Apache Axis"

---------- Original Message ----------------------------------
From: "Vivek Nagulapati" <>
Date:  Fri, 26 Mar 2004 10:52:48 -0600

>Hello All,
>I have few questions on the low-level architecture of Axis.
>1. According to the architecture guide of Axis, it states that there are 3 
>chains of handlers that a MessageContext object has to go through before 
>being serviced
>i) Service ii) Global iii) Transport.
>IIRC, Service handlers i.e., Request/Response handlers can be used to 
>pre-process/post-process SOAP messages. But how can a developer use 
>Transport and Global handlers and what is the main purpose of these 
>2. What would be acting as a transport listener if I deployed the Axis as a 
>WAR in a web application server. How does the control get back to the 
>Application server if I deployed an EJB component as a web service?
>EJB would be hosted by the application server and web service would be 
>deployed in the Axis. So control has to go back to the application server 
>.... how does this work?
>Can anyone point/help me in understanding the lower level workings of Axis?
>Any tutorials/references would also be appreciated!!!
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