ANT: How to modify java.library.path in a buildfile
ant, java
Solution
Ant properties do not work the way you expect: they are immutable, i.e. you cannot change a property's value after you have set it once. If you run
ant -Dsome.other.property=commandlinedefinedpath
the output will no longer show
[echo] some.other.property=test1
Problem
The java.library.path property appears to be read-only. For example when you run ant on the following buildfile ``` <project name="MyProject" default="showprops" basedir="."> <property name="java.library.path" value="test"/> <property name="some.other.property" value="test1"/> <target name="showprops"> <echo>java.library.path=${java.library.path}</echo> <echo>some.other.property=${some.other.property}</echo> </target> </project> ``` you get ``` > ant -version Apache Ant version 1.6.5 compiled on June 2 2005 > ant -Djava.library.path=commandlinedefinedpath Buildfile: build.xml showprops: [echo] java.library.path=commandlinedefinedpath [echo] some.other.property=test1 BUILD SUCCESSFUL Total time: 0 seconds ``` The output indicates that the java.library.path hasn't been changed, but some.other.property was set correctly. I would like to know how to modify the java.library.path within a buildfile. Specifying the java.library.path on the ant command line is not really an easy option, because the library path location is not know at that time. Note: I would like this to work so that I can specify the location of native libraries used in a unit test.