Developing DL-Learner using Eclipse

Instructions on how to prepare Eclipse for developing DL-Learner:

1. Make sure you have Java 6 and Eclipse installed.
2. Install the Subclipse Plugin for Subversion support.
3. “File >> New >> Project” >> “Checkout Projects from SVN”
4. Repository Location: https://dl-learner.svn.sourceforge.net/svnroot/dl-learner (If you are not a developer in the DL-Learner project, you can use http instead of https, but you will only have read access to the repository.)
5. Choose “trunk” and “Finish”.
6. Another project creation wizard should start now. We choose “Java Project”.
7. Project name “DL-Learner” (of course you can use a different name). Choose “Next”.
8. Note: The next two steps can also be done later, after all the files have been downloaded from SVN. To access them just right click on the project and change the project settings (Java Build Path, tab Source). (Optionally you can just remove all source folders and then go to «src/dl-learner» right-click >> "Build Path" >> “use as source-folder”.)
9. Now you need to add src/dl-learner/ as only source folder in the project. (If Eclipse, for instance, has src/ as source folder by default then disable it – the package symbol disappears – and add src/dl-learner/.)
10. Choose DL-Learner/classes/ as output folder (or $project/classes if you used a different project name). Click “Finish”.
11. Eclipse now checks out, so wait for a while. Then select your project in the package explorer and go to “Project” >> “Properties” >> “Java Build Path” >> “Libraries”. Click Add JARs there and add all JARs in the lib folder (you can select several at once using the Ctrl key; do not forget to include jars from all sub folders of /lib as well).
12. Go to “Project” >> “Properties” >> “Java Compiler” >> “Compiler Compliance Level” and set it to 6.0. (Previous compiler levels will report errors.)

You should now be ready to develop DL-Learner in Eclipse. DL-Learner uses the standard code conventions with the only difference that the maximum line length is 100 instead of 80 (Project >> Properties >> Java Code Style >> Formatter >> Edit >> Line Wrapping Tab >> enter “100” as maximum).

Some Java 6 versions ship with restrictions of the internal com.sun.net classes, since there is no long term support for those classes. If you see access restriction errors in Eclipse, then go to “Window” >> “Preferences” >> “Java” >> “Compiler” >> "Errors / Warnings" >> “Deprecated and Restricted API” >> “Forbidden Reference” and set to “Ignore” instead of “Error”. This is only necessary in some Java 6 JDKs.

Similar instructions apply to other IDEs.