Java Utililty Methods SQL Unescape

List of utility methods to do SQL Unescape

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Description

The list of methods to do SQL Unescape are organized into topic(s).

Method

StringunescapeMySQLString(String s)
Unescape any MySQL escape sequences. 
char chars[] = s.toCharArray();
if (chars.length < 2 || chars[0] != chars[chars.length - 1] || (chars[0] != '\'' && chars[0] != '"')) {
    throw new IllegalArgumentException("not a valid MySQL string: " + s);
int j = 1; 
int f = 0; 
for (int i = 1; i < chars.length - 1; i++) {
    if (f == 0) { 
...
StringunescapeSQL(String input)
unescape SQL 
if (input.startsWith("\"") && input.endsWith("\"")) {
    input = input.substring(1, input.length() - 1);
return input.replace("\"\"", "\"").replace("\\\\", "\\");
StringunescapeSQLString(String b)
unescape SQL String 
assert (b.charAt(0) == '\'');
assert (b.charAt(b.length() - 1) == '\'');
StringBuilder sb = new StringBuilder(b.length());
for (int i = 1; i + 1 < b.length(); i++) {
    if (b.charAt(i) == '\\' && i + 2 < b.length()) {
        char n = b.charAt(i + 1);
        switch (n) {
        case '0':
...
StringunescapeSQLString(String b)
unescape SQL String 
Character enclosure = null;
StringBuilder sb = new StringBuilder(b.length());
for (int i = 0; i < b.length(); i++) {
    char currentChar = b.charAt(i);
    if (enclosure == null) {
        if (currentChar == '\'' || b.charAt(i) == '\"') {
            enclosure = currentChar;
        continue;
    if (enclosure.equals(currentChar)) {
        enclosure = null;
        continue;
    if (currentChar == '\\' && (i + 6 < b.length()) && b.charAt(i + 1) == 'u') {
        int code = 0;
        int base = i + 2;
        for (int j = 0; j < 4; j++) {
            int digit = Character.digit(b.charAt(j + base), 16);
            code += digit * multiplier[j];
        sb.append((char) code);
        i += 5;
        continue;
    if (currentChar == '\\' && (i + 4 < b.length())) {
        char i1 = b.charAt(i + 1);
        char i2 = b.charAt(i + 2);
        char i3 = b.charAt(i + 3);
        if ((i1 >= '0' && i1 <= '1') && (i2 >= '0' && i2 <= '7') && (i3 >= '0' && i3 <= '7')) {
            byte bVal = (byte) ((i3 - '0') + ((i2 - '0') * 8) + ((i1 - '0') * 8 * 8));
            byte[] bValArr = new byte[1];
            bValArr[0] = bVal;
            String tmp = new String(bValArr);
            sb.append(tmp);
            i += 3;
            continue;
    if (currentChar == '\\' && (i + 2 < b.length())) {
        char n = b.charAt(i + 1);
        switch (n) {
        case '0':
            sb.append("\0");
            break;
        case '\'':
            sb.append("'");
            break;
        case '"':
            sb.append("\"");
            break;
        case 'b':
            sb.append("\b");
            break;
        case 'n':
            sb.append("\n");
            break;
        case 'r':
            sb.append("\r");
            break;
        case 't':
            sb.append("\t");
            break;
        case 'Z':
            sb.append("\u001A");
            break;
        case '\\':
            sb.append("\\");
            break;
        case '%':
            sb.append("\\%");
            break;
        case '_':
            sb.append("\\_");
            break;
        default:
            sb.append(n);
        i++;
    } else {
        sb.append(currentChar);
return sb.toString();
StringunescapeSqlString(String input)
Unescape the string that comes from query. 
return input;
StringunescapeSQLString(String str, String delim)
unescape SQL String 
return str.replace(delim + delim, delim);