Perhaps the most important step in developing applications with JPOX is the enhancement of compiled classes.
NetBeans 4.x provides a convenient way of integrating this procedure into the
build process without the need for any additional tool or plugin. This is possible because NetBeans 4.x stores
project information in
.properties
files and relies on Ant
for the build process. Class enhancement thus becomes a simple matter of adding a new task to the existing
build.xml
generated by NetBeans 4.x.
This tutorial shows how to integrate JPOX with NetBeans 4.x to simplify the development of JDO applications.
The following components are required to complete this tutorial successfully:
The first thing to do is to register the JPOX components in the
Library Manager
of NetBeans 4.x so
that these become available to any project created with the IDE. This involves creating a new library and adding
the JAR files to it, as shown in the following screenshots.
Once this is done, the NetBeans 4.x will add the JAR files to the classpath whenever the newly-created JPOX library
is selected for a project.
Now create a new project and add the JPOX library to it. This is done by viewing the properties for the project
(right-click on the project and select
Properties...
). Click on
Add Library...
and select the
JPOX library that we created in the previous section.
Note that I store the properties for the
PersistenceManagerFactory
and for Log4j in
.properties
files within the source root folder. This varies according to personal preferences, but I have found this to be very
efficient.
The next step is to write the code for the classes and the meta-data. This is a straightforward exercise left to the
reader. One note of advice, however. Because NetBeans 4.x does not recognise the
package.jdo
file,
it does not auto-complete XML code as it is being entered. The reader may wish to edit the file as
package.xml
and instruct Ant, through an entry in the
build.xml
file to rename that file to
package.jdo
just before the enhancement is performed.
This tutorial does not show how to do this.
Once the code and the metadata has been written, the enhancement process needs to be defined and integrated into
the build process. As stated in the introduction, this requires a simple change to the
build.xml
file.
Click on the
Files
tab, expand the project tree, then open
build.xml
.
Override the
-post-compile
task/target with the following Ant instructions.
<target name="-post-compile">
<echo message="Enhancing the MODULE files"/>
<copy todir="${build.classes.dir}">
<fileset dir="${src.dir}"
includes="**/*.jdo,**/*.properties,**/*.dtd,**/*.xml"/>
</copy>
<path id="module.enhancer.classpath">
<pathelement path="${javac.classpath}"/>
<pathelement location="${build.classes.dir}"/>
</path>
<taskdef name="jpoxenhancer"
classpathref="module.enhancer.classpath"
classname="org.jpox.enhancer.tools.EnhancerTask" />
<jpoxenhancer classpathref="module.enhancer.classpath"/>
</target>
This target is the most convenient for enhancing classes because it occurs just after all classes have been compiled
and is called in any case, whether the project is being built, tested or deployed. This ensures that classes are
always enhanced.
The project can now be built, with the knowledge that the classes will be enhanced in the process.
This concludes our tutorial on how to integrate JPOX with NetBeans 4.x. As can be seen, thanks to NetBeans 4.x project
system based on Ant, development of JDO applications is largely simplified.
This tutorial was provided by a JPOX user Eddy Young.
