ErrorCode.java

/*
 * This file is part of JSTUN. 
 * 
 * Copyright (c) 2005 Thomas King <king@t-king.de> - All rights
 * reserved.
 * 
 * This software is licensed under either the GNU Public License (GPL),
 * or the Apache 2.0 license. Copies of both license agreements are
 * included in this distribution.
 */

package de.javawi.jstun.attribute;

import de.javawi.jstun.util.Utility;
import de.javawi.jstun.util.UtilityException;

public class ErrorCode extends MessageAttribute {
	/*
	 * 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
	 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 0
	 * |Class| Number |
	 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
	 * Reason Phrase (variable) ..
	 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	 */

	public static ErrorCode parse(byte[] data)
			throws MessageAttributeParsingException {
		try {
			if (data.length < 4) {
				throw new MessageAttributeParsingException(
						"Data array too short");
			}
			final byte classHeaderByte = data[3];
			final int classHeader = Utility.oneByteToInteger(classHeaderByte);
			if ((classHeader < 1) || (classHeader > 6)) {
				throw new MessageAttributeParsingException(
						"Class parsing error");
			}
			final byte numberByte = data[4];
			final int number = Utility.oneByteToInteger(numberByte);
			if ((number < 0) || (number > 99)) {
				throw new MessageAttributeParsingException(
						"Number parsing error");
			}
			final int responseCode = (classHeader * 100) + number;
			final ErrorCode result = new ErrorCode();
			result.setResponseCode(responseCode);
			return result;
		} catch (final UtilityException ue) {
			throw new MessageAttributeParsingException("Parsing error");
		} catch (final MessageAttributeException mae) {
			throw new MessageAttributeParsingException("Parsing error");
		}
	}

	int responseCode;

	String reason;

	public ErrorCode() {
		super(MessageAttribute.MessageAttributeType.ErrorCode);
	}

	@Override
	public byte[] getBytes() throws UtilityException {
		int length = reason.length();
		// length adjustment
		if ((length % 4) != 0) {
			length += 4 - (length % 4);
		}
		// message attribute header
		length += 4;
		final byte[] result = new byte[length];
		// message attribute header
		// type
		System.arraycopy(Utility.integerToTwoBytes(typeToInteger(type)), 0,
				result, 0, 2);
		// length
		System.arraycopy(Utility.integerToTwoBytes(length - 4), 0, result, 2, 2);

		// error code header
		final int classHeader = (int) Math.floor(((double) responseCode) / 100);
		result[6] = Utility.integerToOneByte(classHeader);
		result[7] = Utility.integerToOneByte(responseCode % 100);
		final byte[] reasonArray = reason.getBytes();
		System.arraycopy(reasonArray, 0, result, 8, reasonArray.length);
		return result;
	}

	public String getReason() {
		return reason;
	}

	public int getResponseCode() {
		return responseCode;
	}

	public void setResponseCode(int responseCode)
			throws MessageAttributeException {
		switch (responseCode) {
		case 400:
			reason = "Bad Request";
			break;
		case 401:
			reason = "Unauthorized";
			break;
		case 420:
			reason = "Unkown Attribute";
			break;
		case 430:
			reason = "Stale Credentials";
			break;
		case 431:
			reason = "Integrity Check Failure";
			break;
		case 432:
			reason = "Missing Username";
			break;
		case 433:
			reason = "Use TLS";
			break;
		case 500:
			reason = "Server Error";
			break;
		case 600:
			reason = "Global Failure";
			break;
		default:
			throw new MessageAttributeException("Response Code is not valid");
		}
		this.responseCode = responseCode;
	}
}