gov.nist.javax.sip.address.UriDecoder Maven / Gradle / Ivy
/*
* Conditions Of Use
*
* This software was developed by employees of the National Institute of
* Standards and Technology (NIST), an agency of the Federal Government.
* Pursuant to title 15 Untied States Code Section 105, works of NIST
* employees are not subject to copyright protection in the United States
* and are considered to be in the public domain. As a result, a formal
* license is not needed to use the software.
*
* This software is provided by NIST as a service and is expressly
* provided "AS IS." NIST MAKES NO WARRANTY OF ANY KIND, EXPRESS, IMPLIED
* OR STATUTORY, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTY OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT
* AND DATA ACCURACY. NIST does not warrant or make any representations
* regarding the use of the software or the results thereof, including but
* not limited to the correctness, accuracy, reliability or usefulness of
* the software.
*
* Permission to use this software is contingent upon your acceptance
* of the terms of this agreement
*
* .
*
*/
package gov.nist.javax.sip.address;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.nio.charset.UnsupportedCharsetException;
/**
* Replacement for previous RFC2396UrlDecoder class removed for licensing restrictions, hacked from scratch this time
* might be less performant though
* @author Jean Deruelle
*
*/
public class UriDecoder {
static Charset utf8CharSet = null;
static {
try {
utf8CharSet = Charset.forName("UTF8");
} catch (UnsupportedCharsetException e) {
//the situation that UTF-8 is not supported should never happen
throw new RuntimeException("Problem in decodePath: UTF-8 charset not supported.", e);
}
}
/**
* Decode a uri.
*
* Replace %XX (where XX is hexadecimal number) by its corresponding UTF-8 encoded bytes.
*
* @param uri the uri to decode
* @return the decoded uri
*/
public static String decode(String uri) {
// if there is no % we just return the same uri
String uriToWorkOn = uri;
int indexOfNextPercent = uriToWorkOn.indexOf("%");
StringBuilder decodedUri = new StringBuilder();
while(indexOfNextPercent != -1) {
decodedUri.append(uriToWorkOn.substring(0, indexOfNextPercent));
if(indexOfNextPercent + 2 < uriToWorkOn.length()) {
String hexadecimalString = uriToWorkOn.substring(indexOfNextPercent + 1, indexOfNextPercent + 3);
try {
byte hexadecimalNumber = (byte) Integer.parseInt(hexadecimalString, 16);
String correspondingCharacter = utf8CharSet.decode(ByteBuffer.wrap(new byte[] {hexadecimalNumber})).toString();
decodedUri.append(correspondingCharacter);
} catch (NumberFormatException e) {
throw new IllegalArgumentException("Illegal hex characters in pattern %" + hexadecimalString);
}
}
uriToWorkOn = uriToWorkOn.substring(indexOfNextPercent + 3);
indexOfNextPercent = uriToWorkOn.indexOf("%");
}
decodedUri.append(uriToWorkOn);
return decodedUri.toString();
}
}