public static String stringOfArray(Object[] objs, String sep, String prefix, String suffix) {
		StringBuilder res = new StringBuilder(prefix == null ? "" : prefix);
		if (objs != null) {
			boolean first_element = true;
			for (Object o : objs) {
				if (o != null) {
					res.append((first_element ? "" : sep));
					res.append(o.toString());
					first_element = false;
				}
			}
		}
		return res.append(suffix == null ? "" : suffix).toString();
	}