Java print time of last compilation

getCompileTime.java

private static final Date buildDate = getClassBuildTime();

/**
 * Handles files, jar entries, and deployed jar entries in a zip file (EAR).
 * @return The date if it can be determined, or null if not.
 */
private static Date getClassBuildTime() {
    Date d = null;
    Class<?> currentClass = new Object() {}.getClass().getEnclosingClass();
    URL resource = currentClass.getResource(currentClass.getSimpleName() + ".class");
    if (resource != null) {
        if (resource.getProtocol().equals("file")) {
            try {
                d = new Date(new File(resource.toURI()).lastModified());
            } catch (URISyntaxException ignored) { }
        } else if (resource.getProtocol().equals("jar")) {
            String path = resource.getPath();
            d = new Date( new File(path.substring(5, path.indexOf("!"))).lastModified() );    
        } else if (resource.getProtocol().equals("zip")) {
            String path = resource.getPath();
            File jarFileOnDisk = new File(path.substring(0, path.indexOf("!")));
            //long jfodLastModifiedLong = jarFileOnDisk.lastModified ();
            //Date jfodLasModifiedDate = new Date(jfodLastModifiedLong);
            try(JarFile jf = new JarFile (jarFileOnDisk)) {
                ZipEntry ze = jf.getEntry (path.substring(path.indexOf("!") + 2));//Skip the ! and the /
                long zeTimeLong = ze.getTime ();
                Date zeTimeDate = new Date(zeTimeLong);
                d = zeTimeDate;
            } catch (IOException|RuntimeException ignored) { }
        }
    }
    return d;
}