It seems like reflection is possible also with Java although I am not sure if actually an Android apk-file can be decompiled.
In any case, I found a utility called JD-GUI which can be used for opening jar-files such as the wrapper-libraries found in the library-folder of B4A. You can find JD-GUI here:
Yes JD is very useful to view objects in the class files, as for de-compiling the dex files in apk install packages (apk are zip files structured) there are none, it is compiled into a byte code language for the Dalvik vm, very interesting reading, much faster than jvm.