Get a real file path for a resource in Tomcat
// get resource
        URL resU = servletContext.getResource("style.less");

        // get scratch dir
        File workDir = (File) servletContext.getAttribute("javax.servlet.context.tempdir");

        // copy resource to scratch file
        File newFile = new File(workDir, "style.less");
        Files.write(Resources.toByteArray(resU), newFile); // Google Guava

File file = File.createTempFile("style", ".less");
// ...