mitm.common.util.HexUtils.java Source code

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Here is the source code for mitm.common.util.HexUtils.java

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/*
 * Copyright (c) 2008-2011, Martijn Brinkers, Djigzo.
 * 
 * This file is part of Djigzo email encryption.
 *
 * Djigzo is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License 
 * version 3, 19 November 2007 as published by the Free Software 
 * Foundation.
 *
 * Djigzo 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public 
 * License along with Djigzo. If not, see <http://www.gnu.org/licenses/>
 *
 * Additional permission under GNU AGPL version 3 section 7
 * 
 * If you modify this Program, or any covered work, by linking or 
 * combining it with aspectjrt.jar, aspectjweaver.jar, tyrex-1.0.3.jar, 
 * freemarker.jar, dom4j.jar, mx4j-jmx.jar, mx4j-tools.jar, 
 * spice-classman-1.0.jar, spice-loggerstore-0.5.jar, spice-salt-0.8.jar, 
 * spice-xmlpolicy-1.0.jar, saaj-api-1.3.jar, saaj-impl-1.3.jar, 
 * wsdl4j-1.6.1.jar (or modified versions of these libraries), 
 * containing parts covered by the terms of Eclipse Public License, 
 * tyrex license, freemarker license, dom4j license, mx4j license,
 * Spice Software License, Common Development and Distribution License
 * (CDDL), Common Public License (CPL) the licensors of this Program grant 
 * you additional permission to convey the resulting work.
 */
package mitm.common.util;

import java.util.regex.Pattern;

import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.binary.Hex;
import org.apache.commons.lang.StringUtils;

/**
 * Utility functions to convert byte arrays to Hex Strings and vice versa.
 * 
 * @author Martijn Brinkers
 *
 */
public class HexUtils {
    /*
     * Pattern for the detection of hex.
     */
    private final static Pattern HEX_PATTERN = Pattern.compile("\\s*[0-9a-fA-F]+\\s*");

    /**
     * Returns true if the input is hex. If hex is null or empty false is returned. Pending or trailing
     * white-spaces are ignored.
     */
    public static boolean isHex(String hex) {
        if (StringUtils.isBlank(hex)) {
            return false;
        }

        return HEX_PATTERN.matcher(hex).matches();
    }

    public static String hexEncode(byte[] data) {
        return hexEncode(data, null);
    }

    public static String hexEncode(byte[] data, String defaultIfNull) {
        if (data == null) {
            return defaultIfNull;
        }

        return String.copyValueOf(Hex.encodeHex(data)).toUpperCase();
    }

    public static byte[] hexDecode(String hex, byte[] defaultIfNull) throws DecoderException {
        if (hex == null) {
            return defaultIfNull;
        }

        return Hex.decodeHex(hex.toCharArray());
    }

    public static byte[] hexDecode(String hex) throws DecoderException {
        return hexDecode(hex, null);
    }
}