Java Utililty Methods Json Escape

if (source == null) {
    return "";
StringBuilder buf = new StringBuilder();
CharacterIterator it = new StringCharacterIterator(source);
for (char c = it.first(); c != CharacterIterator.DONE; c = it.next()) {
    if (c == '"') {
        buf.append("\\\"");
...

if (aText == null) {
    return null;
final StringBuilder result = new StringBuilder();
StringCharacterIterator iterator = new StringCharacterIterator(aText);
char character = iterator.current();
while (character != StringCharacterIterator.DONE) {
    if (character == '\"') {
...

return s.toString().replace("\"", "\\\"").replace("[", "\\[").replace("]", "\\]").replace("{", "\\{")
        .replace("}", "\\}");

if (in == null || in.isEmpty())
    return in;
return in.replace("\\", "\\\\").replace("\n", "\\n").replace("\"", "\\\"").replace("\r", "\\r")
        .replace("\t", "\\t").replace("\b", "\\b").replace("\f", "\\f");

StringBuilder sb = new StringBuilder();
int len = s.length();
for (int i = 0; i < len; i++) {
    char ch = s.charAt(i);
    switch (ch) {
    case '"':
        sb.append("\\\"");
        break;
...

return EscapeForHtml(str).replace("\\", "\\\\");

StringBuilder sb = new StringBuilder();
sb.append("\"");
for (int i = 0; i < str.length(); i++) {
    char ch = str.charAt(i);
    int found = -1;
    for (int k = 0; k < ESC_MAP.length && found == -1; k++) {
        if (ch == ESC_MAP[k])
            found = k;
...

if (string == null || string.length() == 0) {
    return "\"\"";
char c = 0;
int i;
int len = string.length();
StringBuilder sb = new StringBuilder(len + 4);
String t;
...

StringBuilder escaped = new StringBuilder();
for (int i = 0; i < str.length(); i++) {
    switch (str.charAt(i)) {
    case 0:
        continue;
    case '\b':
        escaped.append("\\\\b");
        continue;
...