StringUtils.java

public static String strJoin (String delim, Collection list) {
	return strJoin(delim, false, list);
}

public static String strJoin (String delim, boolean endSpace, Collection list) {
	if(list == null)
		return null;
	else if(list.size() == 0)
		return "";
	else {
		StringBuilder sb = new StringBuilder();
		for(Object o : list) {
			sb.append(o.toString());
			sb.append(delim);
		}
		sb.delete(sb.length()-delim.length(), sb.length());
		if(endSpace)
			sb.append(' ');
		return sb.toString();
	}
}

public static void sendCenteredMessage (CommandSender sender, String... messages) {
	for(String message : messages) {
		if (message == null || message.trim().isEmpty()) {
			sender.sendMessage("");
			return;
		}

		sender.sendMessage(getCenteringCompensation(message, 154) + message);
	}
}

public static String repeat (String str, int times) {
	return new String(new char[times]).replace("\0", str);
}

public static UUID uuidFromString (String str) {
	if(str.length() == 36)
		try {
			return UUID.fromString(str);
		}catch (Exception badUuidProvided) {}
	else
		try {
			StringBuffer buffer = new StringBuffer(str.trim());
			char delim = '-';
			for(int pos : new int[] {20, 16, 12, 8})
				buffer.insert(pos, delim);
			return UUID.fromString(buffer.toString());
		}catch (Exception badUuidProvided) {}
	return null;
}

public static int getPixelSize (char c) {
	if(c == 'i' || c == 'l' || c == '!' || c == ':' || c == ';' || c == '\'' || c == '|' ||
			c == '.' || c == ',')
		return 1;
	else if(c == 'I' || c == '[' || c == ']' || c == '"' || c == '`' || c == ' ')
		return 3;
	else if(c == 'f' || c == 'k' || c == 't' || c == '(' || c == ')' || c == '{' || c == '}' ||
			c == '<' || c == '>')
		return 4;
	else if((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'B') || (c >= '0' && c <= '9') ||
			(c >= '#' && c <= '&') || c == '*' || c == '+' || c == '-' || c == '=' ||
			c == '?' || c == '/' || c == '\\')
		return 5;
	else if(c == '@')
		return 6;
	else
		return 4;
}

public static int getPixelSize (String str) {
	if(str == null)
		return 0;

	int messagePxSize = 0;
	boolean previousCode = false;
	boolean isBold = false;

	for(char c : str.toCharArray()) {
		if(c == ChatColor.COLOR_CHAR)
			previousCode = true;
		else if(previousCode) {
			previousCode = false;
			char nc = Character.toLowerCase(c);
			if(!isBold) {
				if (nc == ChatColor.BOLD.getChar())
					isBold = true;
			}else if(nc == ChatColor.RESET.getChar())
				isBold = false;
		}else{
			messagePxSize += getPixelSize(c);
			messagePxSize += isBold ? 2 : 1;
		}
	}

	return messagePxSize;
}

public static String getCenteringCompensation (String str, int width) {
	return repeat(" ", (int) Math.ceil((width - (getPixelSize(str)/2))/4d));
}