build.gradle

task indexResources {
    ext.index = { dir ->
        File[] fileList = dir.listFiles()
        ArrayList<String> files = new ArrayList<>()
        for (int i = 0; i < fileList.length; i++) {
            if (fileList[i].isDirectory()) {
                ext.index(fileList[i])
            } else if (fileList[i].getName() == "files.txt") {
                fileList[i].delete()
            } else if (fileList[i].getName().substring(fileList[i].getName().lastIndexOf(".") +
                    1) != "lsd") {
                files.add(fileList[i].getName())
            }
        }
        BufferedWriter writer = new BufferedWriter(new FileWriter(new File(dir.toString()
                + "/files.lsd")))
        for (int i = 0; i < files.size(); i++) {
            writer.write(files.get(i))
            if (i < files.size() - 1) {
                writer.newLine()
            }
        }
        writer.close()
    }

    File root = new File(projectDir.toString() + "/src/main/resources/")
    ext.index(root)
}

compileJava.dependsOn indexResources