Presented by developerWorks, your source for great tutorials

ibm.com/developerWorks

...

*/

public class BasicServlet extends HttpServlet {

These parameters will generate the following

>init param>

s in the deployment

descriptor:

BasicServlet

...

hi

Ant is cool!

bye

XDoc Rocks!

...

Hopefully you are looking at this example and screaming WAIT! Why Wait? I just hard

code init parameters into the source code. Does this give you shivers? No? It should

make you wonder. I was giving a talk at a conference about XDoclet and someone

stopped me at this point and read me the riot act about how the

s were

now hard coded. Not so fast ... Read on.

Step three: combine Ant and XDoclet to configure

components

Hard coding initialization parameters into source code is something that you typically

do not

want to do. The whole idea around having

s is so the Web

component can be customized by the application assembler into a J2EE application.

A better way is to set the init parameters to point to a token as in @bye@ and @hi@,

and then later use the Ant copying with filtering enabled to pass the right token value

for the right application. This assumes you are using Ant to build your project.

You can use Ant filtering to replace tokens in a configuration file with their proper

values for the deployment environment. Filters are another way to support configuring

J2EE components for more than one application. Here is an example Ant script: that

configures the

web.xml

based on a condition:

Enhance J2EE component reuse with XDoclets

Page 11 of 49