Java Utililty Methods String Lower Case

StringBuilder sb = new StringBuilder();
if (flag) {
    sb.append(Character.toLowerCase(srcString.charAt(0)));
} else {
    sb.append(Character.toUpperCase(srcString.charAt(0)));
sb.append(srcString.substring(1));
return sb.toString();
...

return str == null ? null : str.toLowerCase();

String sluggedString = String.join("-", string.split("(?=[A-Z])"));
return sluggedString.toLowerCase();

if (s == null) {
    return null;
if (s.equalsIgnoreCase("CA")) {
    return "ca";
} else if (s.equalsIgnoreCase("KRA")) {
    return "kra";
} else if (s.equalsIgnoreCase("OCSP")) {
...

char[] chars = text.toCharArray();
StringBuilder sb = new StringBuilder();
boolean isFirst = true;
for (char c : chars) {
    if (isFirst) {
        sb.append(Character.toLowerCase(c));
        isFirst = false;
        continue;
...

Converts compound names to the "lower case with separtor style".

char[] chars = string.toCharArray();
StringBuffer buffer = new StringBuffer();
for (int i = 0; i < chars.length; i++) {
    if (Character.isUpperCase(chars[i]) && 
            i > 0 && 
            (Character.isLowerCase(chars[i - 1])
                    || (i < chars.length - 1 && Character.isLowerCase(chars[i + 1]))))
        buffer.append(separator);
...

StringBuilder sb = new StringBuilder();
for (char c : className.toCharArray()) {
    if (c >= 'A' && c <= 'Z' && sb.length() > 0) {
        sb.append('_');
    sb.append(Character.toLowerCase(c));
return sb.toString();
...

return null;