Question

I have a Java project,Parent, which depends on a Child sub-project (in the form of a JAR). This Child depends on library A and B and those get bundled in with Child. Parent uses Aand B as well (meaning direct calls, not indirect through Child. I want to be able to include A and B JARs only once in my project.

When I am compiling Parent, I get a cannot find symbol when it references libraries A and B. I believe this is because Child is on the compile time path, but for some reason the libraries within it are not.

I am using ant as my building tool – is there anything special I should be doing in my javac tags for nested jars? Right now in Parent‘s build.xml I have:

<target name="compile" depends="clean, makedir">
    <javac 
        srcdir="${src.dir}"
        destdir="${build.dir}"
        includeantruntime="false"
        classpathref="build.classpath">
    </javac>
</target>

<path id="build.classpath">
    <fileset dir="${lib.dir}">
        <include name="**/*.jar" />
    </fileset>
</path>

This should be including all of the jars present in my lib folder, but it doesn’t seem to include all of the jars within jars.

Answer 1

My problem stemmed from the fact that Java cannot natively reference jars inside of jars. You’ll need to use something like http://one-jar.sourceforge.net/ to get around it.