How can I exclude sources in a javac task in ant?

Question

I have the following in my build.xml:

  <target name="compile.baz" depends="init">
    <javac destdir="${build.dir}/classes" debug="on">
      <compilerarg value="-Xlint:deprecation"/>
      <src>
        <pathelement location="${src.dir}/com/foo/bar/baz/" />
        <pathelement location="${src.dir}/com/foo/bar/quux/" />
        <!-- Need to exclude ${src.dir}/com/foo/bar/quux/dontwant/ -->
      </src>
      <classpath refid="classpath.jars" />
    </javac>
    ...
  </target>

This mostly does what I want, except that (as the comment says) I do not want the files in
${src.dir}/com/foo/bar/quux/dontwant/ to be compiled by this task (but I do want everything else under ${src.dir}/com/foo/bar/quux/ to be compiled in this task).

I'm a complete ant n00b, and the documentation hasn't been much help to me. I see several places where it says there are various exclude/excludes elements/attributes, but every variation I can think of either has no effect or results in an error like "blah doesn't support the 'exclude' attribute".

Answer 1

Try

<javac>
(...>
<exclude name="${src.dir}/com/foo/bar/quux/dontwant/*" />
(...)
</javac>

Answer 2

I'm not sure about the rest, but the <exclude/> nested element should work in the Javac task. See the sixth example down.

Addendum: Patterns, including the ** notation, are discussed in Directory-based Tasks.

<target name="compile.baz" depends="init">
    <javac destdir="${build.dir}/classes" debug="on">
        <compilerarg value="-Xlint:deprecation"/>
        <src>
            <pathelement location="${src.dir}/com/foo/bar/baz/" />
            <pathelement location="${src.dir}/com/foo/bar/quux/" />
        </src>
        <exclude name="${src.dir}/com/foo/bar/quux/dontwant/**"/>
        ...
    </javac>
    ...
</target>

Answer 3

A couple of people suggested using <exclude>. This didn't work with the way my task was specified. trashgod's answer linked to the sixth example on this page which gave me an idea of how to restructure my task specification.

It looks like my problem was related to the way I was specifying the source files. Rather than using <pathelement> elements in a <src>, like this:

    <src>
      <pathelement location="${src.dir}/com/foo/bar/baz/" />
      <pathelement location="${src.dir}/com/foo/bar/quux/" />
    </src>

I switched to using a single <src> with a path and then a set of <include> elements, like this:

    <src path="${src.dir}" />
    <include name="com/foo/bar/baz/**" />
    <include name="com/foo/bar/quux/**" />

This appears to be functionally identical, but is compatible with the use of <exclude>:

    <exclude name="${src.dir}/com/foo/bar/quux/dontwant/**"/>

(Actually, I'm surprised that what was there in the first place worked at all.)