content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (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.apache.org/licenses/LICENSE-2.0
   * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package mf.org.apache.xerces.impl.dv.util;
  
  /**
   * format validation
   * <p/>
   * This class encodes/decodes hexadecimal data
   *
   * @author Jeffrey Rodriguez
   * @version $Id: HexBin.java 446747 2006-09-15 21:46:20Z mrglavas $
   * @xerces.internal
   */
  public final class HexBin {
      static private final int BASELENGTH = 128;
      static private final int LOOKUPLENGTH = 16;
      static final private byte[] hexNumberTable = new byte[BASELENGTH];
      static final private char[] lookUpHexAlphabet = new char[LOOKUPLENGTH];
  
  
      static {
          for (int i = 0; i < BASELENGTH; i++) {
              hexNumberTable[i] = -1;
          }
          for (int i = '9'; i >= '0'; i--) {
              hexNumberTable[i] = (byte) (i - '0');
          }
          for (int i = 'F'; i >= 'A'; i--) {
              hexNumberTable[i] = (byte) (i - 'A' + 10);
          }
          for (int i = 'f'; i >= 'a'; i--) {
              hexNumberTable[i] = (byte) (i - 'a' + 10);
          }
  
          for (int i = 0; i < 10; i++) {
              lookUpHexAlphabet[i] = (char) ('0' + i);
          }
          for (int i = 10; i <= 15; i++) {
              lookUpHexAlphabet[i] = (char) ('A' + i - 10);
          }
      }
  
      /**
       * Encode a byte array to hex string
       *
       * @param binaryData array of byte to encode
       * @return return encoded string
       */
      static public String encode(byte[] binaryData) {
          if (binaryData == null)
              return null;
          int lengthData = binaryData.length;
          int lengthEncode = lengthData * 2;
          char[] encodedData = new char[lengthEncode];
          int temp;
          for (int i = 0; i < lengthData; i++) {
              temp = binaryData[i];
              if (temp < 0)
                  temp += 256;
              encodedData[i * 2] = lookUpHexAlphabet[temp >> 4];
              encodedData[i * 2 + 1] = lookUpHexAlphabet[temp & 0xf];
          }
          return new String(encodedData);
      }
  
      /**
       * Decode hex string to a byte array
       *
       * @param encoded encoded string
       * @return return array of byte to encode
       */
      static public byte[] decode(String encoded) {
          if (encoded == null)
              return null;
          int lengthData = encoded.length();
          if (lengthData % 2 != 0)
              return null;
  
          char[] binaryData = encoded.toCharArray();
          int lengthDecode = lengthData / 2;
          byte[] decodedData = new byte[lengthDecode];
          byte temp1, temp2;
          char tempChar;
          for (int i = 0; i < lengthDecode; i++) {
              tempChar = binaryData[i * 2];
              temp1 = (tempChar < BASELENGTH) ? hexNumberTable[tempChar] : -1;
              if (temp1 == -1)
                  return null;
              tempChar = binaryData[i * 2 + 1];
              temp2 = (tempChar < BASELENGTH) ? hexNumberTable[tempChar] : -1;
              if (temp2 == -1)
                  return null;
              decodedData[i] = (byte) ((temp1 << 4) | temp2);
          }
          return decodedData;
      }
  }
  