Java error when updating existing Excel spreadsheets using HSSF

Having read Scott Klement's excellent System iNetwork article on
updating existing Excel spreadsheets using the apache POI HSSF api's,
and the updated 2006 article aimed at fixing some Java errors some folks
were getting, I downloaded the revised 2006 source, created the service
program and the sample program, and tried to run it, but I still get a
java error (see details below).

I'm sure the java classes are installed OK, because we also successfully
use Beppe Costagliola's SQL2XLS and SQL2JXL programs, which also use the
HSSF apis. I had also read a suggestion in the archives that the excel
version newer than 2000 might cause trouble when updating existing Excel
sheets, so to eliminate that possibility I created an Excel document
using SQL2XLS, then tried to update it using Scott's HSSFR4.

Here's the error I get:

Cause . . . . . : RPG procedure HSSF_OPEN in program GNODGDF/HSSFR4
received Java exception "java.lang.NoClassDefFoundError:


org/apache/poi/poifs/filesystem/POIFSFileSystem" when calling method
"<init>" with signature "(Ljava.io.InputStream;)V" in class
"org.apache.poi.poifs.filesystem.POIFSFileSystem".


I also sent Scott an email through his website, but the auto-reply
suggested posting here as he may be busy programming sausages, so
hopefully someone else has already run into this problem and is just
dying to share the solution.

Thanks

Greg Fleming

Senior Programmer/Analyst

Everglades Direct, Inc.