static File javaCompileToJar(S src, File destJar) {

  ret javaCompileToJar(src, "", destJar);

}

// returns path to jar

static synchronized File javaCompileToJar(S src, S dehlibs, File destJar) {

  S javaTarget = null; // use default target

  print("Compiling " + l(src) + " chars");

  S md5 = md5(src);

  File jar = destJar;

  Class j = getJavaX();

  if (javaTarget != null)

    setOpt(j, "javaTarget", javaTarget);

  //setOpt(j, "verbose", true);

  File srcDir = cast call(j, "TempDirMaker_make");

  L<S> tok = javaTok(src);

  S className = getNameOfPublicClass(tok);

  if (className == null) className = getNameOfAnyClass(tok);

  if (className == null) fail("No classes defined in source!?");

  S fileName = className + ".java";

  File mainJava = new File(srcDir, fileName);

  //print("main java: " + mainJava.getAbsolutePath());

  saveTextFile(mainJava, src);

  File classesDir = (File) call(j, "TempDirMaker_make");

  new L<File> libraries;

  Matcher m = Pattern.compile("\\d+").matcher(dehlibs);

  while (m.find()) {

    S libID = m.group();

    //print("libID=" + quote(libID));

    assertTrue(isSnippetID(libID));

    libraries.add(loadLibrary(libID));

  }

  S compilerOutput;

  try {

    compilerOutput = (S) call(j, "compileJava", srcDir, libraries, classesDir);

  } catch (Throwable e) {

    compilerOutput = (S) get(getJavaX(), "javaCompilerOutput");

    fail("Compile Error. " + compilerOutput + " " + e);

  }

  if (nempty(compilerOutput)) {

    print("Compiler said: " + compilerOutput);

    //fail("Compile Error. " + compilerOutput);

  }

  // sanity test

  if (!new File(classesDir, className + ".class").exists())

    fail("No class generated (" + className + ")");

  // add sources to .jar

  saveTextFile(new File(classesDir, "main.java"), src);

  // add information about libraries to jar

  if (nempty(dehlibs))

    saveTextFile(new File(classesDir, "libraries"), dehlibs);

  //print("Zipping: " + classesDir.getAbsolutePath() + " to " + jar.getAbsolutePath());

  dir2zip_recurse_verbose = false;

  int n = dir2zip_recurse(classesDir, jar); // cache on success only

  //print("Files zipped: " + n);

  return jar;

}