Using lp_solve in Java with Mac OS X

Sometimes research (at least in my case) means to spend (a lot of) time to configure some application, in this case lp_solve a linear programming solver written in C.

As it often happens there were not so many informations on how to use lp_solve in Java in Mac OS X, the reason is that not a lot of people try to do it in MAC OS X…

If you do it in Windows it is really easy, in Unix you just follow the instructions, but in the Java wrapper the instructions to set up everything (lp_solve + lp_solve Java wrapper) in MAC OS X are WRONG (or incomplete)!

So if you have a mac and want to use lp_solve in your java applications, this post is for you!

After a day of browsing I found in a mailing list a step-by-step guide at this URL: http://osdir.com/ml/mathematics.lpsolve/2006-02/msg00189.html
Thanks to John Gleeson who wrote it.

This is the guide (a mirror in this blog for this guide is always helpful!):

How to build and install the lp_solve Java extension on Mac OS X:

Download and expanded lp_solve_5.5_source.tar.gz into a
directory named 'lp_solve_5.5'.

Download and expand lp_solve_5.5_java.zip into a
directory named 'lp_solve_5.5_java'.

1) Build the lp_solve library.

$ cd lp_solve_5.5/lpsolve55
$ sh ccc.osx

This creates two new files in the lpsolve55 subdirectory:

$ ls liblp*
liblpsolve55.a     liblpsolve55.dylib

2) Install the lp_solve library.

If not already in directory lpsolve55, cd to it.  Copy liblpsolve55.a
and
liblpsolve55.dylib to /usr/local/lib (you may need to create
/usr/local/lib first: sudo mkdir -p /usr/local/lib):

$ sudo cp liblpsolve55.a liblpsolve55.dylib /usr/local/lib

3) Test the build and installation.

$ cd lp_solve_5.5/demo

The ccc.osx script is broken.  The good news is that version 5.5 of
lp_solve fixes the "malloc.h" incompatibility on the Mac that was in
earlier versions.  The Unix/Linux script now works on OS X.  Be
patient...
it may take several seconds to build 'demo':

$ sh ccc

The example problems in the demo should issue no errors and have
"Excellent numeric accuracy ||*|| = 0":

$ ./demo

4) Build the lp_solve JNI extension.

$ cd lp_solve_5.5_java/lib/mac

The script "build-osx" in the mac subdirectory is a DOS text file:

$ file build-osx
build-osx: ASCII English text, with CRLF line terminators

If you try execute this file, you will get "command not found"
errors.  To
convert it into a Unix file, remove the carriage returns:

$ tr -d "\r" < build-osx > build-osx1

Edit build-osx1 to set LPSOLVE_DIR to the location of directory
lp_solve_5.5 on your computer. Change the two occurrences of '5.1' to
'5.5' and the two occurrences of '51' to '55' in the last line of
build-osx1.

$ sh build-osx1

This creates the extension library liblpsolve55j.jnilib.

5) Install  the lp_solve JNI extension.

The file liblpsolve55j.jnilib should be copied to /Library/Java/
Extensions
if you want it to be available to all users.  We assume this will be a
private installation (create the Java extensions directory if necessary;
e.g., mkdir -p ~/Library/Java/Extensions):

$ cp liblpsolve55j.jnilib ~/Library/Java/Extensions

6) Test the Java extension:

$ cd lp_solve_5.5_java/demo
$ java -cp ./demo.jar:../lib/lpsolve55j.jar Demo

The numerical results of the Java Demo should be identical to those
of the
C demo.

There is a Java unit test.  Out of 122 tests, I got 5 errors and 3
failures, all of which could be explained (missing XLI applications,
missing BFP libraries, outdated version numbers in tests, negligible
floating point differrences):

$ java -cp ./unittests.jar:../lib/lpsolve55j.jar:../lib/junit.jar
LpSolveTest

7) For more information about Java programming on Mac OS X:

Java Frequently Asked Questions: Common Development Questions
<http://developer.apple.com/java/faq/development.html>