Xor News

We are starting to use thrift and needed an ant build recipe. Here’s what we came up with. It works good and the only thing that looks like an abstraction leakage to me is that I needed to know the package, the java namespace, for the resultant generated thrift code and the name of one of the thrift generated files. The primary goal was to eliminate running the thrift generator when the generated code is newer than the .thrift files. There isn’t a one to one mapping between .thrift files and generated output so if any of the generated stuff is newer than any of the thrift then it all gets recreated.

I also didn’t want to have to copy the thrift output to someplace else, so a javac target was added to just treat the “gen-java” thrift output as a new source directory for direct java compilation. The normal ant target to compile the java code can now just depend on “thrift-gen”.

  <property name="thrift.dir" value="${basedir}/src/thrift"/>
  <property name="thrift.out.dir" value="${basedir}/src/gen-java"/>
  <property name="thrift.package" value="your/package/name"/>

  <!-- thrift files -->
  <fileset id="thrift.files" dir="${thrift.dir}">
    <include name="**/*.thrift"/>
  </fileset>
  <!-- Determint if thrift generated java is up to date -->
  <target name="thrift-init">
    <dependset>
      <srcfileset refid="thrift.files"/>
      <targetfileset dir = "${thrift.out.dir}/${thrift.package}">
        <include name="**/*.java"/>
      </targetfileset>
    </dependset>
    <available file="${thrift.out.dir}/${thrift.package}/Foo.java"
               property="thrift.uptodate"/>
  </target>

  <!-- Generate thrift java -->
  <target name="thrift-gen" depends="thrift-init" unless="thrift.uptodate">
    <pathconvert property="thrift.file.list" refid="thrift.files"
               pathsep=" " dirsep="/">
    </pathconvert>
    <echo message="Running thrift generator on ${thrift.file.list}"/>
    <exec executable="thrift" dir="${basedir}" failonerror="true">
      <arg line="--strict --gen java -o src ${thrift.file.list}"/>
    </exec>
  </target>