package co.codewizards.cloudstore.core.util;
import static co.codewizards.cloudstore.core.util.AssertUtil.*;
import java.io.CharArrayWriter;
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import java.nio.charset.IllegalCharsetNameException;
import java.nio.charset.StandardCharsets;
import java.nio.charset.UnsupportedCharsetException;
import java.util.BitSet;
/**
* URL-encoder encoding all special characters (that cannot be left unchanged) as "%...".
* <p>
* In contrast to the {@link java.net.URLEncoder URLEncoder}, this class does <b>not</b> encode
* ' ' (space) space as '+' (plus)!
* <p>
* Additionally, this class does not use the default encoding, but always UTF-8, if not specified
* otherwise.
* <p>
* The reason for this class is that {@link java.io.File#toURI() File.toURI()}
* does not encode a "+" sign. Therefore, our URL-encoding and decoding must
* not handle the "+" specifically.
* <p>
* Another reason is <a href="https://java.net/jira/browse/JERSEY-417">JERSEY-417</a>.
* I originally used {@code org.glassfish.jersey.uri.UriComponent.encode(String, Type)}
* at some code locations, but since not all code locations have a dependency on Jersey,
* I decided to switch consistently everywhere to {@code UrlEncoder} and {@link UrlDecoder}.
* <p>
* This class was copied from {@link java.net.URLEncoder URLEncoder} and changed to fit our needs.
* @see UrlDecoder
* @author Marco หงุ่ยตระกูล-Schulze - marco at codewizards dot co
*/
public final class UrlEncoder {
private UrlEncoder() {
}
static BitSet dontNeedEncoding;
static final int caseDiff = ('a' - 'A');
static {
/* The list of characters that are not encoded has been
* determined as follows:
*
* RFC 2396 states:
* -----
* Data characters that are allowed in a URI but do not have a
* reserved purpose are called unreserved. These include upper
* and lower case letters, decimal digits, and a limited set of
* punctuation marks and symbols.
*
* unreserved = alphanum | mark
*
* mark = "-" | "_" | "." | "!" | "~" | "*" | "'" | "(" | ")"
*
* Unreserved characters can be escaped without changing the
* semantics of the URI, but this should not be done unless the
* URI is being used in a context that does not allow the
* unescaped character to appear.
* -----
*
* It appears that both Netscape and Internet Explorer escape
* all special characters from this list with the exception
* of "-", "_", ".", "*". While it is not clear why they are
* escaping the other characters, perhaps it is safest to
* assume that there might be contexts in which the others
* are unsafe if not escaped. Therefore, we will use the same
* list. It is also noteworthy that this is consistent with
* O'Reilly's "HTML: The Definitive Guide" (page 164).
*
* As a last note, Intenet Explorer does not encode the "@"
* character which is clearly not unreserved according to the
* RFC. We are being consistent with the RFC in this matter,
* as is Netscape.
*
*/
dontNeedEncoding = new BitSet(256);
int i;
for (i = 'a'; i <= 'z'; i++) {
dontNeedEncoding.set(i);
}
for (i = 'A'; i <= 'Z'; i++) {
dontNeedEncoding.set(i);
}
for (i = '0'; i <= '9'; i++) {
dontNeedEncoding.set(i);
}
dontNeedEncoding.set('-');
dontNeedEncoding.set('_');
dontNeedEncoding.set('.');
dontNeedEncoding.set('*');
}
/**
* Translates a string into {@code application/x-www-form-urlencoded}
* format using UTF-8.
* @param s {@code String} to be translated.
*/
public static String encode(String s) {
String str = encode(s, StandardCharsets.UTF_8);
return str;
}
/**
* Translates a string into {@code application/x-www-form-urlencoded}
* format using a specific encoding scheme. This method uses the
* supplied encoding scheme to obtain the bytes for unsafe
* characters.
* <p>
* <em><strong>Note:</strong> The <a href=
* "http://www.w3.org/TR/html40/appendix/notes.html#non-ascii-chars">
* World Wide Web Consortium Recommendation</a> states that
* UTF-8 should be used. Not doing so may introduce
* incompatibilities.</em>
*
* @param s {@code String} to be translated.
* @param enc The name of a supported
* <a href="../lang/package-summary.html#charenc">character
* encoding</a>.
* @return the translated {@code String}.
* @exception UnsupportedEncodingException
* If the named encoding is not supported
* @see UrlDecoder#decode(String, String)
* @deprecated UTF-8 should be used; it is thus recommended to invoke {@link #encode(String)} instead.
*/
@Deprecated
public static String encode(String s, String enc) throws UnsupportedEncodingException {
assertNotNull(s, "s");
assertNotNull(enc, "enc");
Charset charset;
try {
charset = Charset.forName(enc);
} catch (IllegalCharsetNameException e) {
throw new UnsupportedEncodingException(enc);
} catch (UnsupportedCharsetException e) {
throw new UnsupportedEncodingException(enc);
}
return encode(s, charset);
}
/**
* Translates a string into {@code application/x-www-form-urlencoded}
* format using a specific encoding scheme. This method uses the
* supplied encoding scheme to obtain the bytes for unsafe
* characters.
* <p>
* <em><strong>Note:</strong> The <a href=
* "http://www.w3.org/TR/html40/appendix/notes.html#non-ascii-chars">
* World Wide Web Consortium Recommendation</a> states that
* UTF-8 should be used. Not doing so may introduce
* incompatibilities.</em>
*
* @param s {@code String} to be translated.
* @param charset The <a href="../lang/package-summary.html#charenc">character encoding</a>.
* @return the translated {@code String}.
* @exception UnsupportedEncodingException
* If the named encoding is not supported
* @see UrlDecoder#decode(String, Charset)
* @deprecated UTF-8 should be used; it is thus recommended to invoke {@link #encode(String)} instead.
*/
@Deprecated
public static String encode(String s, Charset charset) {
assertNotNull(s, "s");
assertNotNull(charset, "charset");
boolean needToChange = false;
StringBuffer out = new StringBuffer(s.length());
CharArrayWriter charArrayWriter = new CharArrayWriter();
for (int i = 0; i < s.length();) {
int c = s.charAt(i);
//System.out.println("Examining character: " + c);
if (dontNeedEncoding.get(c)) {
//System.out.println("Storing: " + c);
out.append((char)c);
i++;
} else {
// convert to external encoding before hex conversion
do {
charArrayWriter.write(c);
/*
* If this character represents the start of a Unicode
* surrogate pair, then pass in two characters. It's not
* clear what should be done if a bytes reserved in the
* surrogate pairs range occurs outside of a legal
* surrogate pair. For now, just treat it as if it were
* any other character.
*/
if (c >= 0xD800 && c <= 0xDBFF) {
/*
System.out.println(Integer.toHexString(c)
+ " is high surrogate");
*/
if ( (i+1) < s.length()) {
int d = s.charAt(i+1);
/*
System.out.println("\tExamining "
+ Integer.toHexString(d));
*/
if (d >= 0xDC00 && d <= 0xDFFF) {
/*
System.out.println("\t"
+ Integer.toHexString(d)
+ " is low surrogate");
*/
charArrayWriter.write(d);
i++;
}
}
}
i++;
} while (i < s.length() && !dontNeedEncoding.get((c = s.charAt(i))));
charArrayWriter.flush();
String str = new String(charArrayWriter.toCharArray());
byte[] ba = str.getBytes(charset);
for (int j = 0; j < ba.length; j++) {
out.append('%');
char ch = Character.forDigit((ba[j] >> 4) & 0xF, 16);
// converting to use uppercase letter as part of
// the hex value if ch is a letter.
if (Character.isLetter(ch)) {
ch -= caseDiff;
}
out.append(ch);
ch = Character.forDigit(ba[j] & 0xF, 16);
if (Character.isLetter(ch)) {
ch -= caseDiff;
}
out.append(ch);
}
charArrayWriter.reset();
needToChange = true;
}
}
return (needToChange? out.toString() : s);
}
}