Samuel Neff elaborated his opinion regarding what is or is not "supported" with regard to extending ColdFusion MX with Java.

His conclusions are sensible, and I agree with them. I would only add Java is supported (as in you want to open a ticket with Technical Support) to the extent that you are accessing Java through the documented mechanisms (cfobject, createobject, etc...), that the intended classes are in ColdFusion's classpath (explicity or implicitly), that the object can be instantiated, and that the object can receive and return parameters as needed.

If there is a problem in any of those areas, Technical Support can investigate them to develop solutions, workarounds, or hotfixes depending on the exact nature of the problem.

However, if the reported problem is isolated to be in the class source, say a bug in the Java code of that class, then that is outside the scope of ColdFusion Technical Support. In that case, an issue should be taken up with the author of that Java program, be it a large vendor such as Sun or a small shop selling custom tags.

See the official Macromedia ColdFusion Support Policy.

See Documentation for Using Java objects in ColdFusion MX

Looking deeper, I haven't actually found any docs that demonstrate the usage of Java reflection such as demonstrated by Sam as seen here: s = ""; c = s.getClass(); fil = c.forName("java.io.File");

Using Java reflection is an edge case as long as instantiating Java objects in this manner without cfobject, createobject, or cfx is not documented, but in my opinion should be supported. Perhaps I can work this into a technote, which would be the first step into official support for this specific technique.