I took up the challenge posted over at Binstock regarding Small Classes and Short Methods and have to say it was an interesting exercise. Overall implementing these suggestions made for much more readable code, and it was certainly more OO after I finished than before.
And indeed it was. It was also one of the more important constraints. From this constraint arose insights into the relationships between elements in the underlying structure. It forced thinking *this much* harder about what is going on, and in the process finding ways to do things that are a bit more OO.7. Don’t use any classes with more than two instance variables. This is perhaps the hardest constraint.
This "50 lines" constraint is the only one that I really felt to be almost impossible to strictly adhere to. If your class overrides Object methods (toString(), equals(), hashCode(), etc.) then you are already eating up some portion of this. I ignored these for purposes of the "lines per class" metric; I don't think the spirit of the exercise suffered.6. Keep entities small. This means no more than 50 lines per class and no more than 10 classes per package.
Current revisions of Eclipse prevent the use of SoyLatte, the OpenJDK port of Java 1.6 for OS X 10.4/10.5. There is an open bug about this, and even better a patch for StandardVMType attached to the bug. I've applied the patch and it does indeed work. There is actually only a single jar used by Eclipse that needs to be built, and most of this can be done within Eclipse itself. The steps for doing this are outlined below.
- Download the Eclipse source. Unzip it.
- From within Eclipse do File | Import... | Existing Projects into Workspace and hit Next. Set your root directory to ${eclipse_src}/plugins/org.eclipse.jdt.launching. Copy the project into the workspace, just to save potential trouble.
- Check out the patch. Copy it to your clipboard.
- To apply the patch go to StandardVMType.java in the Package Explorer, right click, Team | Apply Patch...
- Now to export the plugin, i.e. build the jar needed by Eclipse. Again from within Eclipse: File | Export... | Plug-In Development | Deployable plugs-ins and fragments. Check off the plugin and perhaps change the output directory. Hit finish. You should have the jar with the applied patch in your output directory now.
- Exit Eclipse.
- From your Eclipse home directory (not the source installation, your binary install directory), go to plugins/ and find a file that is named something like org.eclipse.jdt.launching_3.3.1.v20070808_r331.jar. Move this file to a backup directory of your choosing.
- Copy the file generated in step (5) to here.
- Restart Eclipse.
- Go to Eclipse preferences | Java | Installed JREs and try and add SoyLatte as a JRE. If everything worked you should be able to do so without error.
