Java Utililty Methods String Capitalize

boolean capitalize = true;
StringBuilder builder = new StringBuilder(string);
int length = string.length();
for (int index = 0; index < length; index++) {
    char character = builder.charAt(index);
    if (character == '.' || character == '!' || character == '?') {
        capitalize = true;
    } else if (capitalize && !Character.isWhitespace(character)) {
...

return isNotEmpty(string) ? string.substring(0, 1).toUpperCase() + string.substring(1) : string;

if (string != null && string.length() > 0) {
    if (string.length() == 1) {
        return string.toUpperCase();
    return string.substring(0, 1).toUpperCase() + string.substring(1).toLowerCase();
return string;

String[] nameList = string.toLowerCase().replace("_", " ").replace("-", " ").split(" ");
String name = "";
for (String word : nameList) {
    name = name + word.substring(0, 1).toUpperCase() + word.substring(1).toLowerCase() + " ";
if (name.endsWith(" "))
    name = name.substring(0, name.length() - 1);
return name;
...

char[] chars = string.toLowerCase().toCharArray();
boolean found = false;
for (int i = 0; i < chars.length; i++) {
    if (!found && Character.isLetter(chars[i])) {
        chars[i] = Character.toUpperCase(chars[i]);
        found = true;
    } else if (Character.isWhitespace(chars[i])) {
        found = false;
...

if (string.isEmpty()) {
    return string;
if (string.length() == 1) {
    return string.toUpperCase();
final String first = string.substring(0, 1);
final String remaining = string.substring(1);
...

return prepare(string, true);

if (string == null || string.trim().length() == 0) {
    return string;
String[] tokens = string.split("\\s");
string = "";
for (int i = 0; i < tokens.length; i++) {
    char capLetter = Character.toUpperCase(tokens[i].charAt(0));
    string += (i == 0 ? "" : " ") + capLetter + tokens[i].substring(1, tokens[i].length());
...

if (string == null)
    throw new NullPointerException("string is null");
if (string.length() == 0)
    throw new IllegalArgumentException("string is empty");
if (string.length() == 1) {
    return "" + Character.toUpperCase(string.charAt(0));
return Character.toUpperCase(string.charAt(0)) + string.substring(1);
...

if (isEmptyTrim(string)) {
    return string;
if (string.length() < 2) {
    return string.toUpperCase();
return Character.toUpperCase(string.charAt(0)) + string.substring(1).toLowerCase();