How do I set -Dfile.encoding within ant's build.xml?

Question

I've got java source files with iso-8859-1 encoding. When I run ant, I get "warning: unmappable character for encoding UTF-8". I can avoid this if I run ant -Dfile.encoding=iso-8859-1 or add encoding="ISO-8859-1" to each javac statement.

Is there a way to set the property globally within build.xml? <property name="file.encoding" value="ISO-8859-1"> does not work. I know that I can add a foo=ISO-8859-1 property and set encoding="${foo}" to each javac statement, but I'm trying to avoid that.

Answer 1

Ant itself cannot set system properties, but if you really want to, you can write a java program which sets the system property, and execute that from within Ant.

Answer 2

A few options:

1. add -Dfile.encoding=iso-8859-1 to your ANT_OPTS environment variable
2. use <presetdef> to setup defaults for all of your <javac> invocations

Answer 3

If you've got files encoded in a particular way, it's probably best to tell javac that rather than forcing the whole JVM to use a particular encoding. The javac task has an encoding attribute for this reason.

<javac srcdir="${src.dir}" destdir="${build.classes.dir}" encoding="iso-8859-1" />

But really, you should just convert the source files to UTF-8. Everything tastes better in UTF-8. :)