Node:Running SICStus from Java, Previous:Running Java from SICStus, Up:Getting Started
If Java is used as parent application, things are a little more
complicated. There are a couple of things that need to be taken care
of. The first is to specify the correct class path so that Java can find
the Jasper classes (SICStus
, SPTerm
, and so on). This is
done by specifying the pathname of the file jasper.jar
:
% java -classpath $SP_PATH/bin/jasper.jar ...
SP_PATH
does not need to be set; it is only used here as a
placeholder. See the documentation of the Java implementation for
more info on how to set classpaths.
The second is to specify where Java should find the Jasper native
library (libspnative.so
or spnative.dll
), which the
SICStus
class loads into the JVM by invoking the method
System.loadLibrary("spnative")
. Under UNIX, Jasper can usually
figure this out by itself, but in the event that Jasper is used in a
non-standard installation, this will most likely fail. A typical
example of such a failure looks like:
% java -classpath [...]/jasper.jar se.sics.jasper.SICStus Trying to load SICStus. Exception in thread "main" java.lang.UnsatisfiedLinkError: no spnative in java.library.path at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1133) at java.lang.Runtime.loadLibrary0(Runtime.java:470) at java.lang.System.loadLibrary(System.java:745) at se.sics.jasper.SICStus.loadNativeCode(SICStus.java:37) at se.sics.jasper.SICStus.initSICStus(SICStus.java:80) at se.sics.jasper.SICStus.<init>(SICStus.java:111) at se.sics.jasper.SICStus.main(SICStus.java:25)
Under UNIX, this can be fixed by explicitly setting the Java property
java.library.path
to the location of libspnative.so
, like this:
% java -Djava.library.path=/usr/local/lib [...]
Under Windows, Java must be able to find spnative.dll
through the
PATH
environment variable (see Windows). Setting
-Djava.library.path
under Windows
can lead to problems if multiple versions of SICStus has been installed.
If this works properly, SICStus should have been loaded into the JVM
address space. The only thing left is to tell SICStus where the (extended) runtime
library, sprt.sav
(spre.sav
), is located. On those platforms where the
SICStus run-time system can determine its own location, e.g. Windows,
Solaris and Linux, the run-time system will find the runtime library
automatically. Otherwise, you
may choose to specify
this explicitly by either giving a second argument when initializing the
SICStus
object or by specifying the property sicstus.path
:
Example (UNIX):
% java -Dsicstus.path=/usr/local/lib/sicstus-3.12.2
If you do not specify any explicit path, SICStus will search for the runtime library itself.
If everything is set up correctly, you should be able to call main
(which contains a short piece of test-code) in the SICStus root class,
something like this:
% java -Djava.library.path="/usr/local/lib" \ -Dsicstus.path="/usr/local/lib/sicstus-3.12.2" \ -classpath "/usr/local/lib/sicstus-3.12.2/bin/jasper.jar" \ se.sics.jasper.SICStus Trying to load SICStus. If you see this message, you have successfully initialized the SICStus Prolog engine.
Under Windows, it would look something like this, depending on the shell used:
% java -classpath "C:/Program Files/SICStus Prolog 3.12.2/bin/jasper.jar" se.sics.jasper.SICStus Trying to load SICStus. If you see this message, you have successfully initialized the SICStus Prolog engine.
If more than one se.sics.jasper.SICStus
instance will be created,
then the SICStus run-times named e.g.
sprt312_instance_01_.dll
, need to be available as
well. See Runtime Systems on Target Machines.