Deploying the Service
Apache Axis provides two means of deploying Web services: a hot deploy feature through the use of the .jws extension, and a less-elegant solution—XML deployment descriptors. Because of the serialization that our Web service requires, we have no option but to use the deployment descriptors. We need two XML files: One for deploying the service (deploy.wsdd) and one for undeploying the service (undeploy.wsdd). The complete deployment descriptor for our service can be found below:
<deployment xmlns="http://xml.apache.org/axis/wsdd/"
xmlns:java="http://xml.apache.org/axis/wsdd/providers/java">
<service name="WidgetConsumer" provider="java:RPC">
<parameter name="className" value="WidgetConsumer"/>
<parameter name="methodName" value="receiveWidget"/>
<beanMapping qname="myNS:WGT" xmlns:myNS="urn:Widget"
languageSpecificType="java:Widget"/>
</service>
</deployment>
Rather than building the file from scratch, you can steal one from one of the sample applications that ships with Axis. If you do, then the boldface type indicates the data that should be changed. Also, it may be necessary to include the entire <beanMapping/> element because only one of the samples includes it.
The undeployment descriptor is significantly smaller. The entire file can be found below:
<undeployment xmlns="http://xml.apache.org/axis/wsdd/">
<service name="WidgetConsumer"/>
</undeployment>
It simply uses the logical name of one or more services to indicate which services to undeploy.
With those two files created, we are ready to deploy and test the service. Be sure that all three files have been compiled and that the deployment descriptors are in the same directory as the class files. To deploy the service, issue the following command:
java org.apache.axis.client.AdminClient -llocal:///AdminService deploy.wsdd
You should see a message indicating that the descriptor has been successfully processed. To undeploy, run the same command but substitute the deploy.wsdd file for the undeploy.wsdd file. Then you may start up the WidgetFactory, passing in a color, shape, and numeric weight for a widget.
And there you have it. Congratulations!
Web Services Today and Tomorrow
Web Services represent a significant evolution in the areas of distributed computing and industry collaboration. Although they are just now beginning to move from the R&D phase and into production, they have already made a substantial impact upon the way we view software architecture, B2B collaboration, and system integration.
In the next few months, you'll begin to see Web service technologies incorporated into your corporate intranet and B2B extranets as businesses begin to realize the incredible savings in time, money, and headaches that these standards can provide. In the next year or two, Web services will become increasingly prevalent and begin to take on new dimensions. Applications will begin to consider contextual factors such as weather, geography, time of year, time of day, etc. when performing services on our behalf. Likewise, on-demand, Web service-like technologies will find their way into our cellular phones, PDAs, cars, and many other corners of our lives.
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DevX Java Pro Kyle Gabhart is the director of the Java Technology Group for Objective Solutions, a Richardson, TX-based knowledge-transfer group specializing in Java technologies. He also serves as a senior mentor, trainer, and consultant for Objective Solutions, specializing in J2EE, XML, and Web Services technologies. Kyle can be reached at java@objectsoln.com..
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Introduction
A Complex Web Service
Web Service Examples
Deploying the Service
A Simple Web Service
