How to add native library to “java.library.path” w

Question

I got a native library that needs to be added to java.library.path. With JVM argument -Djava.library.path=path... I can set the path as I want.

My problem is that my other library (pentaho reporting) searches fonts based on the default java.library.path (including system directories etc) and the manual setting overrides the default path..

So : how can I add a path entry to the default java.library.path instead of overriding it (which seems to be done with -Djava.library.path)? (I wouldn't want to add the default path by hand, which wouldn't be nice for the sake of deployment)

EDIT: Sorry for missing details; I'm working with Eclipse. (The deployment is done with JNLP and there I can use nativelib under resources)

Answer 1

Had forgotten this issue... I was actually asking with Eclipse, sorry for not stating that originally. And the answer seems to be too simple (at least with 3.5; probably with older versions also):

Java run configuration's Arguments : VM arguments:

-Djava.library.path="${workspace_loc:project}\lib;${env_var:PATH}"

Must not forget the quotation marks, otherwise there are problems with spaces in PATH.

Answer 2

In Windows, like this:

-Djava.library.path="C:/MyLibPath;%PATH%"

%PATH% is your old -Djava.library.path

Answer 3

Can you get round this by calling System.load() programmatically to load your native library? This method (unlike System.loadLibrary()) allows you to specify an absolute path.

Answer 4

For some reason I couldn't get multiple folders to work (well it did for a while but as soon as I needed more dlls and added more folders, none with white spaces in the path). I then copied all needed dlls to one folder and had that as my java.library.path and it worked. I don't have an explanation - if anyone does, it would be great.

Answer 5

https://bugs.eclipse.org/bugs/show_bug.cgi?id=102239 states that there is no substitution mechanics implemented in Eclipse's launcher, at least no up to release Juno.

Thus it is (almost) impossible to append or prepend another library folder to java.library.path when launching Eclipse without prior knowledge of the default setting.

I wrote almost, cause it should be possible to let Eclipse startup, dump the content of java.library.path and stop Eclipse in one command. The dump would the be parsed and then taken as the input for launching Eclipse, i.e.

#!/bin/bash
# get default value of java.library.path (somehow)
default_lib_path=$( start_dump_stop_eclipse_somehow )  

# now launch Eclipse
eclipse --launcher.appendVmargs \
         -vmargs \
         -Djava.library.path="/my/native/lib/folder:${default_lib_path}"

Answer 6

Window->Preferences->Java->Installed JREs. Then choose your current JRE(JDK) and click Edit. Fill Default VM Arguments: -Djava.library.path=/usr/local/xuggler/lib. Done!