Java Utililty Methods String Unescape

StringBuilder outBuffer = new StringBuilder(str.length());
for (int index = 0; index < str.length();) {
    char c = str.charAt(index++);
    if (c == '\\') {
        c = str.charAt(index++);
        if (c == 't') {
            c = '\t';
        } else if (c == 'r') {
...

StringBuilder sb = new StringBuilder();
String[] codeStrs = str.split("\\\\u");
for (String codeStr : codeStrs) {
    if (codeStr.isEmpty()) {
        continue;
    try {
        if (codeStr.length() <= 4) {
...

if (str == null || str.length() == 0)
    return ""; 
StringBuffer sb = new StringBuffer();
int len = str.length();
for (int i = 0; i < len; i++) {
    char ch = str.charAt(i);
    switch (ch) {
    case '&':
...

StringBuilder sb = new StringBuilder();
boolean inEscape = false;
for (int i = 0; i < str.length(); ++i) {
    if (inEscape) {
        inEscape = false;
        sb.append(str.charAt(i));
    } else {
        if (str.charAt(i) == '\\') {
...

if (str == null) {
    return null;
StringBuilder unescapedString = new StringBuilder();
char[] charArray = str.toCharArray();
for (int i = 0; i < charArray.length; i++) {
    char c = charArray[i];
    switch (c) {
...

if (str == null) {
    return str;
String temp = str, sub;
temp = "";
char ch = ' ';
int index = str.indexOf("%u");
while (index >= 0) {
...

StringBuffer sb = new StringBuffer(str.length());
char[] array = str.toCharArray();
for (int cnt = 0; cnt < array.length; cnt++) {
    if (array[cnt] != '\\') {
        sb.append(array[cnt]);
    } else {
        switch (array[++cnt]) {
        case 'n':
...

StringBuilder b = new StringBuilder(str.length());
int i = 0;
int l = str.length();
while (l > 0) {
    char c = str.charAt(i);
    if (c == '+') {
        b.append(' ');
        i++;
...

return unescape(str, DEFAULT_ESCAPECHAR);

return unescape(str, false);