Some Notes on Axis2 Version 1.1

This is probably the first in a series.

* See http://ws.apache.org/axis2/ of course. Get the code and unpack.

* To run inside Tomcat, go to axis2-1.1.1/webapp and run "ant create.war" (you need ant). Then get the war from axis2-1.1.1/dist and drop into Tomcat's webapp directory.

* I'll start by just summarizing the documentation, so these are my "cut to the chase" notes.

* Start with a POJO service like the one below.

package pojo.magic;
public class PojoBean {
String name="Jojomojo";
public PojoBean() {
}
public String getName() {
return name;
}
public void setName(String name) {
this.name=name;
}
}

* To deploy this service by hand, you must do the following steps.
1. Compile it (use javac -d . PojoBean.java).
2. Copy the resulting directory (pojo) to the webapps/axis2/WEB-INF/services.
3. Mkdir webapps/axis2/WEB-INF/services/pojo/META-INF
4. Create a service.xml file with your service metadata.

* Your service.xml file will look like this:

<service name="PojoService" scope="application">
<description>
Sample POJO service
</description>
<messageReceivers>
<messageReceiver
mep="http://www.w3.org/2004/08/wsdl/in-only"
class="org.apache.axis2.rpc.receivers.RPCInOnlyMessageReceiver"/>
<messageReceiver
mep="http://www.w3.org/2004/08/wsdl/in-out"
class="org.apache.axis2.rpc.receivers.RPCMessageReceiver"/>
</messageReceivers>
<parameter name="ServiceClass">pojo.magic.PojoBean</parameter>
</service>

* I created this file BY HAND. Why, oh why, do they not have tool to do this? Note also that you will need to restart this webapp (or the whole tomcat server) if you make a mistake writing the XML or put anything in the wrong place. Apparently there's no more JWS.

* Also note you'd better not get confused (as I initially did) about the format for this file. There seem to be serveral different versions of server.xml, depending on how you develop your service--that is, if you build your service with Axis2's AXIOM classes (see below), then your service.xml will be completely different.

* You can also make .aar files for your services. In the above example, this would just be the contents of the pojo directory that I copied into WEB-INF/services.

* Take a quick look at what you have wrought:

- WSDL is here: http://localhost:8080/axis2/services/PojoService?wsdl
- Schema is here: http://localhost:8080/axis2/services/PojoService?xsd
- Invoke REST: http://localhost:8080/axis2/rest/PojoService/getName

Examine the WSDL. You will note that they explicitly define messages using an XML schema (the ?xsd response) even for this very simple service, which only gets/sets with strings.

* Note of course the limitations of my POJO: I only have String i/0 parameters, which can be
mapped to XSD defined types. I did not try to send/receive structured objects (ie other Javabeans), and of course I did not try to get/set Java objects.

* It is interesting that they support REST as well as WSDL/SOAP style invocation by default. For the above service, Axis is definitely a sledgehammer, since you could easily make the REST version of this in two seconds with a JSP page. And for more complicated inputs, REST would be really difficult.

Using AXIOM

* This would be really overkill for our simple little POJO.

* Presumably this is useful if you need to send more complicated structured messages (which need to be serialized as XML). But you don't really won't to do this if you can use XML Beans instead. That is, use the tool that specializes in serialization/deserialization of XML<->Java.