Perhaps the most important step in developing applications with DataNucleus is the enhancement of compiled classes. NetBeans 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 has native integration with Maven and Ant. Any DataNucleus project based on Maven will open and run as is with Netbeans. No changes are needed in the project nor in Netbeans. When using Ant Class enhancement thus becomes a simple matter of adding a new task to the existing build.xml generated by NetBeans.
This tutorial shows how to integrate DataNucleus with NetBeans 7.0 to simplify the development of JDO applications. Please contribute any updates to this guide that you have since the developers of DataNucleus don't use Netbeans
NetBeans has native integration with Maven. If your project builds with Maven then it will also build with NetBeans without any change. Unzip the sample project to $home/DNSamples/datanucleus-samples-jdo-tutorial-3.0
The sample project comes with a pom.xml. When you try to open this project NetBeans will automatically detect it as maven project.
Start Netbeans
Open Maven Project
Clean Build the project
You will see a success message as below
------------------------------------------------------------------------ BUILD SUCCESS ------------------------------------------------------------------------ Total time: 5.406s Finished at: Fri Aug 05 09:23:53 IST 2011 Final Memory: 14M/108M ------------------------------------------------------------------------
Run Main Class
The results can be seen in the output window
DataNucleus AccessPlatform with JDO =================================== Persisting products Product and Book have been persisted Retrieving Extent for Products >> Book : JRR Tolkien - Lord of the Rings by Tolkien >> Product : Sony Discman [A standard discman from Sony] Executing Query for Products with price below 150.00 >> Book : JRR Tolkien - Lord of the Rings by Tolkien Deleting all products from persistence Deleted 2 products End of Tutorial ------------------------------------------------------------------------ BUILD SUCCESS ------------------------------------------------------------------------ Total time: 6.221s Finished at: Fri Aug 05 09:27:43 IST 2011 Final Memory: 7M/106M ------------------------------------------------------------------------
The first thing to do is to register the DataNucleus components in the Library Manager of NetBeans 7 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
Open Library Manager
Add New Library with Name DN3 - Repeat the process for DN3Deps
Add all the libraries under $home/datanucleus-accessplatform-full-deps-3.0.0-release/lib to DN3. Add all the libraries under $home/datanucleus-accessplatform-full-deps-3.0.0-release/deps to DN3Deps
Once this is done, the NetBeans 7 will add the JAR files to the classpath whenever the newly-created DN3 and DN3Deps library is selected for a project.
Delete pom.xml from the downloaded samples project. NetBeans treats any folder with pom.xml as maven project. Copy the datanucleus.properties to src/java in the downloaded samples project.
Now create a new project from existing sources.
Remember to Select Java Project with Existing Source
Click Next and Add Folder. The source folder should point to datanucleus-samples-jdo-tutorial-3.0/src/java
Then click Next and Finish
Now we have the sucessfuly created the sample project using Ant
Add the Libraries created in first set to this project. Right-Click on Libraries in the Projects Tab
Add DN3 library to your project. Also add DN3Deps
We also need to add JDBC support to our project. Add this using add Add jars option. Right-Click on Libraries in the Projects Tab and select Add jars
Add hsqldb
The enhancement process needs to be defined and integrated into the build process. As stated in the introduction, this requires a simple change to the nbbuild.xml file.
TypeSafe Queries :- Datanucleus generates addtional code for supporting type safe queries. Ensure that "Enable Annotation processing" check box is selected, which is under Project Properties | build | compiling
Click on the Files tab, expand the project tree, then open nbbuild.xml
Override the -post-compile task/target with the following Ant instructions.
<target name="-post-compile" depends="init"> <path id="module.enhancer.classpath"> <pathelement path="${javac.classpath}"/> <pathelement location="${build.classes.dir}"/> </path> <taskdef name="datanucleusenhancer" classpathref="module.enhancer.classpath" classname="org.datanucleus.enhancer.EnhancerTask"/> <echo message="start datanucleusenhancer"/> <datanucleusenhancer classpathref="module.enhancer.classpath" dir="${build.classes.dir}" verbose="true"> <fileset dir="${build.classes.dir}"> <include name="**/*.class"/> </fileset> </datanucleusenhancer> <echo message="end datanucleusenhancer"/> </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. Ensure that the Compile on Save option is turned off. Enable Annotation Processing should be turned ON
The project can now be built, with the knowledge that the classes will be enhanced in the process.
Output window will show some thing similar to this
BUILD SUCCESSFUL (total time: 2 seconds) Run the main class The output window will show as below Product and Book have been persisted Retrieving Extent for Products >> Book : JRR Tolkien - Lord of the Rings by Tolkien >> Product : Sony Discman [A standard discman from Sony] Executing Query for Products with price below 150.00 >> Book : JRR Tolkien - Lord of the Rings by Tolkien Deleting all products from persistence Deleted 2 products End of Tutorial BUILD SUCCESSFUL (total time: 2 seconds)