code: public static SipSessionKey parseSipSessionKey(
  			String sipSessionKey) throws ParseException {
  		if(logger.isDebugEnabled()) {
  			logger.debug("parseSipSessionKey - sipSessionKey=" + sipSessionKey);
  		}
  		
  		int indexOfLeftParenthesis = sipSessionKey.indexOf("(");
  		// see http://code.google.com/p/sipservlets/issues/detail?id=207
  		// support for Call-ID with ')' character
  		int indexOfRightParenthesis = sipSessionKey.lastIndexOf(")");
  		if(indexOfLeftParenthesis == -1) {
  			throw new ParseException("The left parenthesis could not be found in the following key " + sipSessionKey, 0);
  		}
  		if(indexOfRightParenthesis == -1) {
  			throw new ParseException("The right parenthesis could not be found in the following key " + sipSessionKey, 0);
  		}
  		String sipSessionKeyToParse = sipSessionKey.substring(indexOfLeftParenthesis+1, indexOfRightParenthesis);
  		if(logger.isDebugEnabled()) {
  			logger.debug("sipSession key to parse " + sipSessionKeyToParse );
  		}
  		StringTokenizer stringTokenizer = new StringTokenizer(sipSessionKeyToParse, SESSION_KEY_SEPARATOR);		
  		String fromTag = stringTokenizer.nextToken();
  		String toTag = null;
  		if(stringTokenizer.countTokens() == 4) {
  			// Issue 2365 : to tag needed for getApplicationSession().getSipSession(<sessionId>) to return forked session and not the parent one
  			toTag = stringTokenizer.nextToken();
  		}
  		String callId = stringTokenizer.nextToken();
  		String applicationSessionId = stringTokenizer.nextToken();
  		String applicationName = stringTokenizer.nextToken();
  		
  		return new SipSessionKey(fromTag, toTag, callId, applicationSessionId, applicationName);
  	}
docs: Parse a sip application key that was previously generated and put as an http request param
  through the encodeURL method of SipApplicationSession
  @param sipSessionKey the stringified version of the sip application key
  @return the corresponding sip application session key
  @throws ParseException if the stringfied key cannot be parse to a valid key