Java - way to prevent Collections Framework use for assignment?

Question

For a particular assignment (in Java), I'm having my students implement some ADTs, and I am preventing them from using any of the Java Collections Framework that we have covered previously (List, Collections, LinkedList, Stack, Deque, etc.).

What are some good ways to enforce / detect this restriction to make sure they are not using these interfaces and classes for this particular assignment?

Is there a compiler directive / switch / setting to prevent usage of java.util entirely? I mean, that's some serious hobbling, but for this assignment so far it can get by on just java.lang . I would have liked to used Iterator , and they need to have Generics.

I was going to try to detect import statements, but reflection can't get those from the byte code. One post suggested QDox on source files for getting imports, but I didn't want to load an additional library for this. Should I just write a script to scan their source files for java.util.x imports?

I was thinking of looking at their class files with reflection to see if any members where of those list of types... but kinda messy :/

Most of my assignments are auto-graded / unit-tested because of the number of students, though for some assignments I peek at all the code to give them additional feedback. So for now, I have to do that on this one just to catch those who didn't follow directions.

Just curious what some of you would do for this.

Answer 1

There are a bunch of dependency analysers available, but if you are using a recent JDK, jdeps (part of the JDK since 8) might be sufficient for your needs.

For example:

$ jdeps -verbose:class -p java.util ~/opt/antlrworks/antlrworks-1.5.2-complete.jar

lists the dependencies on java.util.* classes. Should be easy to call it from a small shell script or similar for automatic checking.

It is not impossible to get around detection by using reflection ( Class.forName ...), but if any of your students manage/know how to do this, they deserve a bonus point anyway. ;-)

More info is available here: https://wiki.openjdk.java.net/display/JDK8/Java+Dependency+Analysis+Tool

Answer 2

One solution to this would be to make use of checkstyle, and turn on the 'IllegalImport' rule. https://checkstyle.sourceforge.io/config_imports.html#IllegalImport

Simply add the classes you want to disallow to the list, and if they are present in the code, the build will fail.