jodd-core/src/main/java/jodd/util/StringUtil.java
private static String changeFirstCharacterCase(final boolean capitalize, final String string) {
		int strLen = string.length();
		if (strLen == 0) {
			return string;
		}

		char ch = string.charAt(0);
		char modifiedCh;
		if (capitalize) {
			modifiedCh = Character.toUpperCase(ch);
		} else {
			modifiedCh = Character.toLowerCase(ch);
		}

		if (modifiedCh == ch) {
			// no change, return unchanged string
			return string;

		}

		char[] chars = string.toCharArray();
		chars[0] = modifiedCh;
		return new String(chars);
	}
private static String changeFirstCharacterCase(final boolean capitalize, final String string) {
		int strLen = string.length();
		if (strLen == 0) {
			return string;
		}

		char ch = string.charAt(0);
		char modifiedCh;
		if (capitalize) {
			modifiedCh = Character.toUpperCase(ch);
		} else {
			modifiedCh = Character.toLowerCase(ch);
		}

		if (modifiedCh == ch) {
			// no change, return unchanged string
			return string;

		}

		char[] chars = string.toCharArray();
		chars[0] = modifiedCh;
		return new String(chars);
	}
Internal method for changing the first character case.