Faster String → Long conversion

gistfile1.java

	public static Long tryAndGetLong(String string, int radix) {
		try {
			return Long.parseLong(string, radix);
		} catch (NumberFormatException e) {
			return null;
		}
	}

	private static final String DIGITS = "0123456789";
	private static final String UPPER_DIGIT_MAP = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
	private static final String LOWER_DIGIT_MAP = "abcdefghijklmnopqrstuvwxyz";

	public static Long speedLongParse(final String string, final int radix) {
		final char[] chars = string.toCharArray();
		int i = chars[0] == '-' ? 1 : 0;
		for (;i < chars.length; i++) {
			final char c = chars[i];
			final int digitIdx = DIGITS.indexOf(c);
			if (digitIdx >= radix) {
				return null;
			}
			final int upperIdx = UPPER_DIGIT_MAP.indexOf(c);
			if (upperIdx >= radix - 10) {
				return null;
			}
			final int lowerIdx = LOWER_DIGIT_MAP.indexOf(c);
			if (lowerIdx >= radix - 10) {
				return null;
			}
			if (digitIdx < 0 && upperIdx < 0 && lowerIdx < 0) {
				return null;
			}
		}
		// Should never return null
		return tryAndGetLong(string, radix);
	}