Several folks are having difficulty finding/using the Java compiler.
Surprisingly, the compiler classes are not included with the SDK even though
they are documented in the manual.  Here are details on getting Java running
on the Amiga SDK.

First, we need the missing class files from the 1.1.6 JDK.  Download the file
              ftp://metalab.unc.edu/pub/linux/devel/lang/java/blackdown.org/JDK-1.1.6/i386/glibc/v5/jdk_1.1.6-v5-glibc-x86.tar.bz2

and unpack the classes.zip included 

bzcat jdk_1.1.6-v5-glibc-x86.tar.bz2 | tar xf - jdk116_v5/lib/classes.zip

Now, since the javac command calls jcode directly (as opposed to the java
shell script), you have to unpack the classes.zip into a supplemental
hierarchy.  I suggest a new directly called jdk116 so as to avoid overwriting
any classfiles that are provided with the Amiga SDK.

cd /; mkdir jdk116; cd jdk116; unzip /classes.zip

The /app/stdio/javac shell script overrides whatever classpath the user might
have set and is looking for (presumably compiler) classes in /app/java/javac,
which does not exist.  So, I just decided to go ahead and make it exist by
using soft links on the Linux side of things:

on Amiga side:

touch app/java

cd AmigaRoot/app/java; mkdir javac; cd javac; ln -s AmigaRoot/jdk116/* .

Thus, the Java compiler now works with the minimal manipulation of stock shell
scripts &c.