sclass JavaCompilation {
  File srcDir;
  L<File> libraries;
  File classesDir;
  bool verbose = true;
  S sourceLevel = "11";
  S moreOptions = "-warn:none";
  
  L<File> sources;
  File optionsFile;
  S compilerOutput;
  
  swappable void invokeJavaCompiler() {
    compilerOutput = invokeEcj_direct(optionsFile);
  }
  
  run {
    // collect sources

    sources = findJavaSourceFiles(srcDir);
    if (sources.isEmpty())
      throw new IOException("No sources found");

    // compile

    optionsFile = File.createTempFile("ecj", "", javaxTempDir());
    try {
      if (verbose) printWithMS("Compiling " + sources.size() + " source(s) to " + classesDir.getPath());
      if (verbose) printWithMS("Libraries: " + libraries);
      
      S options = unnull(moreOptions) + " -source " + sourceLevel + " -target " + sourceLevel;
      options += " -d " + pqO(classesDir.getPath());
      libraries.add(pathToJavaxJar());
      makeOptionsFileForJavaCompiler(optionsFile, sources, libraries, options);
      if (verbose) printWithMS("Options: " + loadTextFile(optionsFile));
      classesDir.mkdirs();
      time "invokeJavaCompiler" {
        invokeJavaCompiler();
      }
    } finally {
      optionsFile.delete();
    }
  }
}