Java Utililty Methods URI Encode

byte[] utf8buf = null;
StringBuilder sb = null;
for (int k = 0, length = str.length(); k != length; ++k) {
    char c = str.charAt(k);
    if (encodeUnescaped(c, fullUri)) {
        if (sb != null) {
            sb.append(c);
    } else {
        if (sb == null) {
            sb = new StringBuilder(length + 3);
            sb.append(str);
            sb.setLength(k);
            utf8buf = new byte[6];
        if (0xDC00 <= c && c <= 0xDFFF) {
            throw new URISyntaxException(str, c + " outside of valid range");
        int value;
        if (c < 0xD800 || 0xDBFF < c) {
            value = c;
        } else {
            k++;
            if (k == length) {
                throw new URISyntaxException(str, "out of chars");
            char c2 = str.charAt(k);
            if (!(0xDC00 <= c2 && c2 <= 0xDFFF)) {
                throw new URISyntaxException(str, "outside of valid range");
            value = ((c - 0xD800) << 10) + (c2 - 0xDC00) + 0x10000;
        int L = oneUcs4ToUtf8Char(utf8buf, value);
        assert utf8buf != null;
        for (int j = 0; j < L; j++) {
            int d = 0xff & utf8buf[j];
            sb.append('%');
            sb.append(toHexChar(d >>> 4));
            sb.append(toHexChar(d & 0xf));
return (sb == null) ? str : sb.toString();

StringBuilder out = new StringBuilder();
for (int i = 0; i < uri.length(); i++) {
    char c = uri.charAt(i);
    if (c >= 'a' && c <= 'z') {
        out.append(c);
    } else if (c >= '0' && c <= '9') {
        out.append(c);
    } else if (c >= 'A' && c <= 'Z') {
...

String result = urlEncodeUtf8(uriPart);
result = result.replaceAll("\\+", "%20");
result = result.replaceAll("%2D", "-");
result = result.replaceAll("%5F", "_");
result = result.replaceAll("%2E", ".");
result = result.replaceAll("%7E", "~");
result = result.replaceAll("\\*", "%2A");
return result;
...

String decodedUri = URLDecoder.decode(uri, "UTF-8");
if (uri.compareTo(decodedUri) == 0)
    return URLEncoder.encode(uri, "UTF-8");
else
    return uri;

try {
    return new URI(null, null, uri, null).toASCIIString();
} catch (URISyntaxException e) {
    throw new IllegalArgumentException(e);

String uriString;
try {
    uriString = URLEncoder.encode(uri.toString(), DEFAULT_ENCODING);
} catch (final UnsupportedEncodingException e) {
    return null;
return URI.create(uriString);

String result;
try {
    result = URLEncoder.encode(s, "UTF-8").replaceAll("\\+", "%20").replaceAll("\\%21", "!")
            .replaceAll("\\%27", "'").replaceAll("\\%28", "(").replaceAll("\\%29", ")")
            .replaceAll("\\%7E", "~");
catch (Exception e) {
    result = s;
...

if (string == null) {
    return null;
try {
    return URLEncoder.encode(string, "UTF-8").replace("+", "%20");
} catch (UnsupportedEncodingException ex) {
    throw new IllegalStateException(ex);

String tmp = null;
tmp = uri.replaceAll(" ", "%20");
tmp = tmp.replaceAll("<", "%3C");
tmp = tmp.replaceAll(">", "%3E");
tmp = tmp.replaceAll("'", "%27");
tmp = tmp.replaceAll("\\x28", "%28"); 
tmp = tmp.replaceAll("\\x29", "%29"); 
tmp = tmp.replaceAll("\\x22", "%22"); 
...

String newUri = "";
StringTokenizer st = new StringTokenizer(uri, "/ ", true);
while (st.hasMoreTokens()) {
    String tok = st.nextToken();
    if (tok.equals("/")) {
        newUri += "/";
    } else if (tok.equals(" ")) {
        newUri += "%20";
...