NumericCharacterReference.java Source code

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Here is the source code for NumericCharacterReference.java

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/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is part of dcm4che, an implementation of DICOM(TM) in
 * Java(TM), available at http://sourceforge.net/projects/dcm4che.
 *
 * The Initial Developer of the Original Code is
 * TIANI Medgraph AG.
 * Portions created by the Initial Developer are Copyright (C) 2003-2005
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 * Gunter Zeilinger <gunter.zeilinger@tiani.com>
 * Franz Willer <franz.willer@gwi-ag.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

/**
 *
 * Helper class to encode/decode Strings with Numeric Character References as defined in SGML.
 * 
 * @author franz.willer
 *
 * @version $Revision: 2101 $
 * @since 25.11.2005
 */
public class NumericCharacterReference {

    /**
     * Decodes a String with Numeric Character References.
     * <p>
     * 
     * @param str A NCR encoded String
     * @param unknownCh, A character that is used if nnnn of &#nnnn; is not a int.
     * 
     * @return The decoded String.
     */
    public static String decode(String str, char unknownCh) {
        StringBuffer sb = new StringBuffer();
        int i1 = 0;
        int i2 = 0;

        while (i2 < str.length()) {
            i1 = str.indexOf("&#", i2);
            if (i1 == -1) {
                sb.append(str.substring(i2));
                break;
            }
            sb.append(str.substring(i2, i1));
            i2 = str.indexOf(";", i1);
            if (i2 == -1) {
                sb.append(str.substring(i1));
                break;
            }

            String tok = str.substring(i1 + 2, i2);
            try {
                int radix = 10;
                if (tok.charAt(0) == 'x' || tok.charAt(0) == 'X') {
                    radix = 16;
                    tok = tok.substring(1);
                }
                sb.append((char) Integer.parseInt(tok, radix));
            } catch (NumberFormatException exp) {
                sb.append(unknownCh);
            }
            i2++;
        }
        return sb.toString();
    }

    /**
     * Encode a String with Numeric Character Refernces.
     * <p>
     * Formats each character < 0x20 or > 0x7f to &#nnnn; where nnnn is the char value as int.
     * <p>
     *  
     * @param str The raw String
     * @return The encoded String
     */
    public static String encode(String str) {
        char[] ch = str.toCharArray();
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < ch.length; i++) {
            if (ch[i] < 0x20 || ch[i] > 0x7f)
                sb.append("&#").append((int) ch[i]).append(";");
            else
                sb.append(ch[i]);
        }
        return sb.toString();
    }
}