WebGoat/java/org/owasp/webgoat/session/ParameterParser.java

package org.owasp.webgoat.session;

import java.util.Enumeration;
import java.util.StringTokenizer;
import java.util.Vector;
import java.util.regex.Pattern;
import javax.servlet.ServletRequest;
import org.owasp.webgoat.util.HtmlEncoder;


/***************************************************************************************************
 * 
 * 
 * This file is part of WebGoat, an Open Web Application Security Project utility. For details,
 * please see http://www.owasp.org/
 * 
 * Copyright (c) 2002 - 2007 Bruce Mayhew
 * 
 * This program is free software; you can redistribute it and/or modify it under the terms of the
 * GNU General Public License as published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
 * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License along with this program; if
 * not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 * 
 * Getting Source ==============
 * 
 * Source for this application is maintained at code.google.com, a repository for free software
 * projects.
 * 
 * For details, please see http://code.google.com/p/webgoat/
 * 
 * @author Jeff Williams <a href="http://www.aspectsecurity.com">Aspect Security</a>
 */
public class ParameterParser
{

	private final static String ALLOWED_CHARACTERS = "_$()-?.@!,:;=//+"; // Don't
	// allow
	// #&
	// specifically

	private ServletRequest request;

	/**
	 * Constructs a new ParameterParser to handle the parameters of the given request.
	 * 
	 * @param request
	 *            the servlet request
	 */
	public ParameterParser(ServletRequest request)
	{
		this.request = request;
	}

	/**
	 * Description of the Method
	 * 
	 * @param s
	 *            Description of the Parameter
	 * @return Description of the Return Value
	 */
	private String clean(String s)
	{
		StringBuffer clean = new StringBuffer();

		for (int loop = 0; loop < s.length(); loop++)
		{
			char c = s.charAt(loop);

			if (Character.isLetterOrDigit(c) || Character.isWhitespace(c) || (ALLOWED_CHARACTERS.indexOf(c) != -1))
			{
				clean.append(c);
			}
			else
			{
				clean.append('.');
			}
		}

		return (clean.toString());
	}

	/**
	 * Gets the named parameter value as a boolean
	 * 
	 * @param name
	 *            the parameter name
	 * @return the parameter value as a boolean
	 * @exception ParameterNotFoundException
	 *                if the parameter was not found
	 */
	public boolean getBooleanParameter(String name) throws ParameterNotFoundException
	{
		return new Boolean(getStringParameter(name)).booleanValue();
	}

	/**
	 * Gets the named parameter value as a boolean, with a default. Returns the default value if the
	 * parameter is not found.
	 * 
	 * @param name
	 *            the parameter name
	 * @param def
	 *            the default parameter value
	 * @return the parameter value as a boolean, or the default
	 */
	public boolean getBooleanParameter(String name, boolean def)
	{
		try
		{
			return getBooleanParameter(name);
		} catch (Exception e)
		{
			return def;
		}
	}

	/**
	 * Gets the booleanSubParameter attribute of the ParameterParser object
	 * 
	 * @param first
	 *            Description of the Parameter
	 * @param next
	 *            Description of the Parameter
	 * @param def
	 *            Description of the Parameter
	 * @return The booleanSubParameter value
	 */
	public boolean getBooleanSubParameter(String first, String next, boolean def)
	{
		try
		{
			return new Boolean(getSubParameter(first, next)).booleanValue();
		} catch (Exception e)
		{
			return def;
		}
	}

	/**
	 * Gets the named parameter value as a byte
	 * 
	 * @param name
	 *            the parameter name
	 * @return the parameter value as a byte
	 * @exception ParameterNotFoundException
	 *                if the parameter was not found
	 * @exception NumberFormatException
	 *                if the parameter value could not be converted to a byte
	 */
	public byte getByteParameter(String name) throws ParameterNotFoundException, NumberFormatException
	{
		return Byte.parseByte(getStringParameter(name));
	}

	/**
	 * Gets the named parameter value as a byte, with a default. Returns the default value if the
	 * parameter is not found or cannot be converted to a byte.
	 * 
	 * @param name
	 *            the parameter name
	 * @param def
	 *            the default parameter value
	 * @return the parameter value as a byte, or the default
	 */
	public byte getByteParameter(String name, byte def)
	{
		try
		{
			return getByteParameter(name);
		} catch (Exception e)
		{
			return def;
		}
	}

	/**
	 * Gets the named parameter value as a char
	 * 
	 * @param name
	 *            the parameter name
	 * @return the parameter value as a char
	 * @exception ParameterNotFoundException
	 *                if the parameter was not found or was the empty string
	 */
	public char getCharParameter(String name) throws ParameterNotFoundException
	{
		String param = getStringParameter(name);

		if (param.length() == 0)
		{
			throw new ParameterNotFoundException(name + " is empty string");
		}
		else
		{
			return (param.charAt(0));
		}
	}

	/**
	 * Gets the named parameter value as a char, with a default. Returns the default value if the
	 * parameter is not found.
	 * 
	 * @param name
	 *            the parameter name
	 * @param def
	 *            the default parameter value
	 * @return the parameter value as a char, or the default
	 */
	public char getCharParameter(String name, char def)
	{
		try
		{
			return getCharParameter(name);
		} catch (Exception e)
		{
			return def;
		}
	}

	/**
	 * Gets the classNameParameter attribute of the ParameterParser object
	 * 
	 * @param name
	 *            Description of the Parameter
	 * @return The classNameParameter value
	 */
	public String getClassNameParameter(String name) throws ParameterNotFoundException
	{
		String p = getStringParameter(name);
		StringTokenizer st = new StringTokenizer(p);

		return (st.nextToken().trim());
	}

	// FIXME: check for [a-zA-Z].([a-zA-Z])*

	/**
	 * Gets the classNameParameter attribute of the ParameterParser object
	 * 
	 * @param name
	 *            Description of the Parameter
	 * @param def
	 *            Description of the Parameter
	 * @return The classNameParameter value
	 */
	public String getClassNameParameter(String name, String def)
	{
		try
		{
			return getClassNameParameter(name);
		} catch (Exception e)
		{
			return def;
		}
	}

	/**
	 * Gets the named parameter value as a double
	 * 
	 * @param name
	 *            the parameter name
	 * @return the parameter value as a double
	 * @exception ParameterNotFoundException
	 *                if the parameter was not found
	 * @exception NumberFormatException
	 *                if the parameter could not be converted to a double
	 */
	public double getDoubleParameter(String name) throws ParameterNotFoundException, NumberFormatException
	{
		return new Double(getStringParameter(name)).doubleValue();
	}

	/**
	 * Gets the named parameter value as a double, with a default. Returns the default value if the
	 * parameter is not found.
	 * 
	 * @param name
	 *            the parameter name
	 * @param def
	 *            the default parameter value
	 * @return the parameter value as a double, or the default
	 */
	public double getDoubleParameter(String name, double def)
	{
		try
		{
			return getDoubleParameter(name);
		} catch (Exception e)
		{
			return def;
		}
	}

	/**
	 * Gets the named parameter value as a float
	 * 
	 * @param name
	 *            the parameter name
	 * @return the parameter value as a float
	 * @exception ParameterNotFoundException
	 *                if the parameter was not found
	 * @exception NumberFormatException
	 *                if the parameter could not be converted to a float
	 */
	public float getFloatParameter(String name) throws ParameterNotFoundException, NumberFormatException
	{
		return new Float(getStringParameter(name)).floatValue();
	}

	/**
	 * Gets the named parameter value as a float, with a default. Returns the default value if the
	 * parameter is not found.
	 * 
	 * @param name
	 *            the parameter name
	 * @param def
	 *            the default parameter value
	 * @return the parameter value as a float, or the default
	 */
	public float getFloatParameter(String name, float def)
	{
		try
		{
			return getFloatParameter(name);
		} catch (Exception e)
		{
			return def;
		}
	}

	/**
	 * Gets the named parameter value as an IP String, with a default. Returns the default value if
	 * the parameter is not found or is the empty string.
	 * 
	 * @param name
	 *            the parameter name
	 * @param def
	 *            the default parameter value
	 * @return the parameter value as a String, or the default
	 */
	public String getIPParameter(String name, String def)
	{
		try
		{
			return getIPParameter(name);
		} catch (Exception e)
		{
			return def;
		}
	}

	/**
	 * Gets the named parameter value as an IP String
	 * 
	 * @param name
	 *            the parameter name
	 * @return the parameter value as a valid IP String or an Empty string if invalid
	 * @exception ParameterNotFoundException
	 *                if the parameter was not found or was the empty string
	 */
	public String getIPParameter(String name) throws ParameterNotFoundException
	{
		boolean valid = true;
		String[] values = request.getParameterValues(name);
		String value;

		if (values == null)
		{
			throw new ParameterNotFoundException(name + " not found");
		}
		else if (values[0].length() == 0)
		{
			throw new ParameterNotFoundException(name + " was empty");
		}
		else
		{
			// trim illegal characters
			value = clean(values[0].trim());

			if (value.indexOf("&") > 0)
			{
				// truncate additional parameters that follow &
				value = value.substring(0, value.indexOf("&"));
			}

			// validate the IP ex: 124.143.12.254
			int startIndex = 0;
			int endIndex = 0;
			int octetCount = 0;
			int octetValue;
			String octet;

			// if no .'s then it's not an IP
			if (value.indexOf(".") >= 0)
			{
				while ((valid == true) && (octetCount < 4))
				{
					endIndex = value.indexOf(".", startIndex);

					if (endIndex == -1)
					{
						endIndex = value.length();
					}

					octet = value.substring(startIndex, endIndex);
					startIndex = endIndex + 1;

					try
					{
						octetValue = Integer.parseInt(octet);

						if ((octetValue <= 0) || (octetValue >= 256))
						{
							valid = false;
						}
					} catch (Exception e)
					{
						valid = false;
					}

					octetCount++;
				}
			}
			else
			{
				// Not a valid IP
				valid = false;
			}

			// Check for any extra garbage. If the last octet was a large value
			// it would be trapped by the above range check.
			if (value.length() != endIndex)
			{
				valid = false;
			}

			return valid ? value : null;
		}
	}

	/**
	 * Gets the named parameter value as a int
	 * 
	 * @param name
	 *            the parameter name
	 * @return the parameter value as a int
	 * @exception ParameterNotFoundException
	 *                if the parameter was not found
	 * @exception NumberFormatException
	 *                if the parameter could not be converted to a int
	 */
	public int getIntParameter(String name) throws ParameterNotFoundException, NumberFormatException
	{
		return Integer.parseInt(getStringParameter(name));
	}

	/**
	 * Gets the named parameter value as a int, with a default. Returns the default value if the
	 * parameter is not found.
	 * 
	 * @param name
	 *            the parameter name
	 * @param def
	 *            the default parameter value
	 * @return the parameter value as a int, or the default
	 */
	public int getIntParameter(String name, int def)
	{
		try
		{
			return getIntParameter(name);
		} catch (Exception e)
		{
			return def;
		}
	}

	/**
	 * Gets the named parameter value as a long
	 * 
	 * @param name
	 *            the parameter name
	 * @return the parameter value as a long
	 * @exception ParameterNotFoundException
	 *                if the parameter was not found
	 * @exception NumberFormatException
	 *                if the parameter could not be converted to a long
	 */
	public long getLongParameter(String name) throws ParameterNotFoundException, NumberFormatException
	{
		return Long.parseLong(getStringParameter(name));
	}

	/**
	 * Gets the named parameter value as a long, with a default. Returns the default value if the
	 * parameter is not found.
	 * 
	 * @param name
	 *            the parameter name
	 * @param def
	 *            the default parameter value
	 * @return the parameter value as a long, or the default
	 */
	public long getLongParameter(String name, long def)
	{
		try
		{
			return getLongParameter(name);
		} catch (Exception e)
		{
			return def;
		}
	}

	/**
	 * Determines which of the required parameters were missing from the request. Returns null if
	 * all the parameters are present.
	 * 
	 * @param requestuired
	 *            Description of the Parameter
	 * @return an array of missing parameters, or null if none are missing
	 */
	public String[] getMissingParameters(String[] requestuired)
	{
		Vector<String> missing = new Vector<String>();

		for (int i = 0; i < requestuired.length; i++)
		{
			String val = getStringParameter(requestuired[i], null);

			if (val == null)
			{
				missing.addElement(requestuired[i]);
			}
		}

		if (missing.size() == 0)
		{
			return null;
		}
		else
		{
			String[] ret = new String[missing.size()];
			missing.copyInto(ret);

			return ret;
		}
	}

	/**
	 * Gets the parameterNames attribute of the ParameterParser object
	 * 
	 * @return The parameterNames value
	 */
	public Enumeration getParameterNames()
	{
		if (request == null) { return (null); }

		return request.getParameterNames();
	}

	/**
	 * Gets the parameterValues attribute of the ParameterParser object
	 * 
	 * @param name
	 *            Description of the Parameter
	 * @return The parameterValues value
	 */
	public String[] getParameterValues(String name)
	{
		if (request == null) { return (null); }

		return request.getParameterValues(name);
	}

	/**
	 * Gets the rawParameter attribute of the ParameterParser object
	 * 
	 * @param name
	 *            Description of the Parameter
	 * @param def
	 *            Description of the Parameter
	 * @return The rawParameter value
	 */
	public String getRawParameter(String name, String def)
	{
		try
		{
			return getRawParameter(name);
		} catch (Exception e)
		{
			return def;
		}
	}

	/**
	 * Gets the rawParameter attribute of the ParameterParser object
	 * 
	 * @param name
	 *            Description of the Parameter
	 * @return The rawParameter value
	 * @exception ParameterNotFoundException
	 *                Description of the Exception
	 */
	public String getRawParameter(String name) throws ParameterNotFoundException
	{
		String[] values = request.getParameterValues(name);

		if (values == null)
		{
			throw new ParameterNotFoundException(name + " not found");
		}
		else if (values[0].length() == 0) { throw new ParameterNotFoundException(name + " was empty"); }

		return (values[0]);
	}

	/**
	 * Gets the named parameter value as a short
	 * 
	 * @param name
	 *            the parameter name
	 * @return the parameter value as a short
	 * @exception ParameterNotFoundException
	 *                if the parameter was not found
	 * @exception NumberFormatException
	 *                if the parameter could not be converted to a short
	 */
	public short getShortParameter(String name) throws ParameterNotFoundException, NumberFormatException
	{
		return Short.parseShort(getStringParameter(name));
	}

	/**
	 * Gets the named parameter value as a short, with a default. Returns the default value if the
	 * parameter is not found.
	 * 
	 * @param name
	 *            the parameter name
	 * @param def
	 *            the default parameter value
	 * @return the parameter value as a short, or the default
	 */
	public short getShortParameter(String name, short def)
	{
		try
		{
			return getShortParameter(name);
		} catch (Exception e)
		{
			return def;
		}
	}

	/**
	 * Gets the named parameter value as a String
	 * 
	 * @param name
	 *            the parameter name
	 * @return the parameter value as a String
	 * @exception ParameterNotFoundException
	 *                if the parameter was not found or was the empty string
	 */
	public String getStringParameter(String name) throws ParameterNotFoundException
	{
		String[] values = request.getParameterValues(name);
		String value;

		if (values == null)
		{
			throw new ParameterNotFoundException(name + " not found");
		}
		else if (values[0].length() == 0)
		{
			throw new ParameterNotFoundException(name + " was empty");
		}
		else
		{
			// trim illegal characters
			value = clean(values[0].trim());

			if (value.indexOf("&") > 0)
			{
				// truncate additional parameters that follow &
				value = value.substring(0, value.indexOf("&"));
			}

			return value;
		}
	}

	/**
	 * Gets the named parameter value as a String, with a default. Returns the default value if the
	 * parameter is not found or is the empty string.
	 * 
	 * @param name
	 *            the parameter name
	 * @param def
	 *            the default parameter value
	 * @return the parameter value as a String, or the default
	 */
	public String getStringParameter(String name, String def)
	{
		try
		{
			return getStringParameter(name);
		} catch (Exception e)
		{
			return def;
		}
	}

	/**
	 * Gets the subParameter attribute of the ParameterParser object
	 * 
	 * @param first
	 *            Description of the Parameter
	 * @param next
	 *            Description of the Parameter
	 * @param def
	 *            Description of the Parameter
	 * @return The subParameter value
	 */
	public String getSubParameter(String first, String next, String def)
	{
		try
		{
			return getSubParameter(first, next);
		} catch (Exception e)
		{
			return def;
		}
	}

	/**
	 * Gets the parameter named 'next' following the parameter 'first'. Presumes the structure:
	 * first=firstvalue&next=nextValue
	 * 
	 * @param first
	 *            Description of the Parameter
	 * @param next
	 *            Description of the Parameter
	 * @return The subParameter value
	 * @exception ParameterNotFoundException
	 *                Description of the Exception
	 */
	public String getSubParameter(String first, String next) throws ParameterNotFoundException
	{
		String[] values = request.getParameterValues(first);
		String value;

		if (values == null)
		{
			throw new ParameterNotFoundException(first + " not found");
		}
		else if (values[0].length() == 0)
		{
			throw new ParameterNotFoundException(first + " was empty");
		}
		else
		{
			value = clean(values[0].trim());

			int idx = value.indexOf("&") + 1;

			// index of first char of first sub-param name
			if (idx == 0) { throw new ParameterNotFoundException("No subparameter key"); }

			value = value.substring(idx);

			// System.out.println("= = = = = =Parameter parser looking for " +
			// next + " in " + value );
			int nextValueIndex = value.indexOf(next + "=");

			// System.out.println("= = = = = =Parameter parser nextValueIndex =
			// " + nextValueIndex );
			if (nextValueIndex < 0) { throw new ParameterNotFoundException("No subparameter value"); }

			nextValueIndex += (next.length() + 1);

			if (nextValueIndex >= 0)
			{
				value = value.substring(nextValueIndex);
			}
			else
			{
				throw new ParameterNotFoundException(next + " not found");
			}
		}

		if (value.indexOf("&") > 0)
		{
			// truncate additional parameters that follow &
			value = value.substring(0, value.indexOf("&"));
		}

		// System.out.println("=-=-=-=-=ParameterParser returning value " +
		// value );
		return value;
	}

	/**
	 * Gets the wordParameter attribute of the ParameterParser object
	 * 
	 * @param name
	 *            Description of the Parameter
	 * @return The wordParameter value
	 */
	public String getWordParameter(String name) throws ParameterNotFoundException
	{
		String p = getStringParameter(name);
		StringTokenizer st = new StringTokenizer(p);

		return (st.nextToken().trim());
	}

	// FIXME: check for [a-zA-Z]

	/**
	 * Gets the wordParameter attribute of the ParameterParser object
	 * 
	 * @param name
	 *            Description of the Parameter
	 * @param def
	 *            Description of the Parameter
	 * @return The wordParameter value
	 */
	public String getWordParameter(String name, String def)
	{
		try
		{
			return getWordParameter(name);
		} catch (Exception e)
		{
			return def;
		}
	}

	/**
	 * Gets the specified parameter from the request and validates it against the provided regular
	 * expression. If the regular expression check fails, the default value is returned instead.
	 * 
	 * @param name
	 *            The name of the parameter to retrieve from the request.
	 * @param def
	 *            The default value of the parameter.
	 * @param regexpattern
	 *            The precompiled regular expression to be used to validate the parameter.
	 * @return The validated parameter value, or the default value if validation failed.
	 */
	private String getRegexParameter(String name, String def, Pattern regexpattern) throws ValidationException
	{
		try
		{
			return getRegexParameter(name, regexpattern);
		} catch (Exception e)
		{
			// System.out.println("Exception occured in defined pattern match");
			// e.printStackTrace();
			return def;
		}
	}

	/**
	 * Gets the specified parameter from the request and validates it against the provided regular
	 * expression. If the regular expression check fails, the default value is returned instead.
	 * 
	 * @param name
	 *            The name of the parameter to retrieve from the request.
	 * @param def
	 *            The default value of the parameter.
	 * @param regexpattern
	 *            The precompiled regular expression to be used to validate the parameter.
	 * @return The validated parameter value, or the default value if validation failed.
	 */
	private String getRegexParameter(String name, Pattern regexpattern) throws ParameterNotFoundException,
			ValidationException
	{
		String param = getStringParameter(name);

		if (regexpattern.matcher(param).matches())
		{
			return param;
		}
		else
		{
			// System.out.println(param + " didn't match defined pattern.");
			throw new ValidationException(name + " contained an invalid value");
		}
	}

	public String getStrictAlphaParameter(String name, int maxLength) throws ParameterNotFoundException,
			ValidationException
	{
		String alphaRegEx = "^[a-zA-Z\\s]{0," + maxLength + "}$";
		Pattern alphaPattern = Pattern.compile(alphaRegEx);

		return getRegexParameter(name, alphaPattern);
	}

	public String getStrictNumericParameter(String name, int maxLength) throws ParameterNotFoundException,
			ValidationException
	{
		String numericRegEx = "^\\d{0," + maxLength + "}$";
		Pattern numericPattern = Pattern.compile(numericRegEx);

		return getRegexParameter(name, numericPattern);
	}

	private static final String SSNREGEX = "^\\d{3}-\\d{2}-\\d{4}$";

	private static final Pattern Ssnpattern = Pattern.compile(SSNREGEX);

	public String getSsnParameter(String name) throws ParameterNotFoundException, ValidationException
	{
		return getRegexParameter(name, Ssnpattern);
	}

	// Validates format for major brands of credit card.
	// private static final String CCNREGEX =
	// "^(?:(?<Visa>4\\d{3})|(?<Mastercard>5[1-5]\\d{2})|(?<Discover>6011)|(?<DinersClub>(?:3[68]\\d{2})|(?:30[0-5]\\d))|(?<AmericanExpress>3[47]\\d{2}))([
	//-]?)(?(DinersClub)(?:\\d{6}\\1\\d{4})|(?(AmericanExpress)(?:\\d{6}\\1\\d{5})|(?:\\d{4}\\1\\d{4
	// }\\1\\d{4})))$";
	private static final String CCNREGEX = "^\\d{16}$";

	private static final Pattern Ccnpattern = Pattern.compile(CCNREGEX);

	public String getCcnParameter(String name) throws ParameterNotFoundException, ValidationException
	{
		return getRegexParameter(name, Ccnpattern);
	}

	private static final String ZIPREGEX = "^\\d{5}(-\\d{4})?$";

	private static final Pattern Zippattern = Pattern.compile(ZIPREGEX);

	public String getZipParameter(String name) throws ParameterNotFoundException, ValidationException
	{
		return getZipParameter(name, null);
	}

	public String getZipParameter(String name, String def) throws ValidationException
	{
		return getRegexParameter(name, def, Zippattern);
	}

	private static final String PHONEREGEX = "^\\(?[\\d]{3}\\)?[\\s-]?[\\d]{3}[\\s-]?[\\d]{4}$";

	// Or this more forgiving pattern:
	// private static final String PHONEREGEX = "^([\\-()+ 0-9x])+$";
	private static final Pattern phonepattern = Pattern.compile(PHONEREGEX);

	public String getPhoneParameter(String name) throws ParameterNotFoundException, ValidationException
	{
		return getPhoneParameter(name, null);
	}

	public String getPhoneParameter(String name, String def) throws ValidationException
	{
		return getRegexParameter(name, def, phonepattern);
	}

	private static final String EMAILREGEX = "^[\\w-]+(?:\\.[\\w-]+)*@(?:[\\w-]+\\.)+[a-zA-Z]{2,7}$";

	private static final Pattern emailpattern = Pattern.compile(EMAILREGEX);

	public String getEMailParameter(String name) throws ParameterNotFoundException, ValidationException
	{
		return getEMailParameter(name, null);
	}

	public String getEMailParameter(String name, String def) throws ValidationException
	{
		return getRegexParameter(name, def, emailpattern);
	}

	private static final String DATEREGEX = "([\\/ .,:0-9a-zA-Z])+$";

	private static final Pattern datepattern = Pattern.compile(DATEREGEX);

	public String getDateParameter(String name) throws ParameterNotFoundException, ValidationException
	{
		return getDateParameter(name, null);
	}

	public String getDateParameter(String name, String def) throws ValidationException
	{
		return getRegexParameter(name, def, datepattern);
	}

	private static final String URLREGEX = "^(((https?)://)([-()_.!~*';/?:@&=+$,A-Za-z0-9])+)([).!';/?:,][[:blank:]])?$";

	private static final Pattern URLpattern = Pattern.compile(URLREGEX);

	public String getURLParameter(String name) throws ParameterNotFoundException, ValidationException
	{
		return getURLParameter(name, null);
	}

	public String getURLParameter(String name, String def) throws ValidationException
	{
		return getRegexParameter(name, def, URLpattern);
	}

	protected static String htmlEncode(String s)
	{
		return HtmlEncoder.encode(s);
	}

	/**
	 * Description of the Method
	 * 
	 * @return Description of the Return Value
	 */
	public String toString()
	{
		StringBuffer s = new StringBuffer("[");
		Enumeration e = getParameterNames();

		while (e.hasMoreElements())
		{
			String key = (String) e.nextElement();
			s.append(key + "=" + getParameterValues(key)[0]);

			// FIXME: Other values?
			if (e.hasMoreElements())
			{
				s.append(",");
			}
		}

		s.append("]");

		return (s.toString());
	}

	/**
	 * Description of the Method
	 * 
	 * @param request
	 *            Description of the Parameter
	 */
	public void update(ServletRequest request)
	{
		this.request = request;
	}
}