Merge points (or merge files) are a mechanism XDoclet provides for merging in
a user-written file with the template file. It has various uses:
- Not all class libraries out there use XDoclet @tags. You should be able to
add Struts' servlet for example to the web application you're working on using
XDoclet. So <deploymentDescriptor/> sub-task of <webdoclet/> (in fact the
web_xml.j tempalte file, which is used by <deploymentDescriptor/>) provides a
servlets.xml merge points. So you can create a file named servlets.xml and
specifiy all not-XDoclet-annotated servlets in it.
- Putting @tags in code is good for development but sometimes you want to do
deployment to various servers for example. Should you modify the @tags each
time for each deployment? No, for deployment-oriented activities (for example
specifying the table name an EJB maps to) it's better to use merge-points and
use different copies of the merge point for different deployments.
- Merge points provides pluggability. You can use customization merge points
to add a customized content to the generated stuff.