content: /*
   * Copyright (C) 2006 The Android Open Source Project
   * 
   * Licensed 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 com.google.polo.pairing;
  
  import java.nio.charset.Charset;
  
  public class HexDump {
      private final static char[] HEX_DIGITS = {
              '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
  
      public static String dumpHexString(final byte[] array) {
          return dumpHexString(array, 0, array.length);
      }
  
      public static String dumpHexString(final byte[] array, final int offset, final int length) {
          final StringBuilder result = new StringBuilder();
  
          final byte[] line = new byte[16];
          int lineIndex = 0;
  
          result.append("\n0x")
                .append(toHexString(offset));
  
          for (int i = offset; i < (offset + length); i++) {
              if (lineIndex == 16) {
                  result.append(" ");
  
                  for (int j = 0; j < 16; j++) {
                      if ((line[j] > ' ') && (line[j] < '~')) {
                          result.append(new String(line, j, 1, Charset.forName("UTF-8")));
                      } else {
                          result.append(".");
                      }
                  }
  
                  result.append("\n0x");
                  result.append(toHexString(i));
                  lineIndex = 0;
              }
  
              final byte b = array[i];
              result.append(" ");
              result.append(HEX_DIGITS[(b >>> 4) & 0x0F]);
              result.append(HEX_DIGITS[b & 0x0F]);
  
              line[lineIndex++] = b;
          }
  
          if (lineIndex != 16) {
              int count = (16 - lineIndex) * 3;
              count++;
              for (int i = 0; i < count; i++) {
                  result.append(" ");
              }
  
              for (int i = 0; i < lineIndex; i++) {
                  if ((line[i] > ' ') && (line[i] < '~')) {
                      result.append(new String(line, i, 1));
                  } else {
                      result.append(".");
                  }
              }
          }
  
          return result.toString();
      }
  
      public static String toHexString(final byte b) {
          return toHexString(toByteArray(b));
      }
  
      public static String toHexString(final byte[] array) {
          return toHexString(array, 0, array.length);
      }
  
      public static String toHexString(final byte[] array, final int offset, final int length) {
          final char[] buf = new char[2 + length * 2];
  
          buf[0] = '0';
          buf[1] = 'x';
  
          int bufIndex = 2;
          for (int i = offset; i < (offset + length); i++) {
              final byte b = array[i];
              buf[bufIndex++] = HEX_DIGITS[(b >>> 4) & 0x0F];
              buf[bufIndex++] = HEX_DIGITS[b & 0x0F];
          }
  
          return new String(buf);
      }
  
      public static String toHexString(final int i) {
          return toHexString(toByteArray(i));
      }
  
      public static byte[] toByteArray(final byte b) {
          final byte[] array = new byte[1];
          array[0] = b;
          return array;
      }
  
      public static byte[] toByteArray(final int i) {
          final byte[] array = new byte[4];
  
          array[3] = (byte) (i & 0xFF);
          array[2] = (byte) ((i >> 8) & 0xFF);
          array[1] = (byte) ((i >> 16) & 0xFF);
          array[0] = (byte) ((i >> 24) & 0xFF);
  
          return array;
      }
  
      private static int toByte(final char c) {
          if ((c >= '0') && (c <= '9')) {
              return c - '0';
          }
          if ((c >= 'A') && (c <= 'F')) {
              return (c - 'A') + 10;
          }
          if ((c >= 'a') && (c <= 'f')) {
              return (c - 'a') + 10;
          }
  
          throw new RuntimeException("Invalid hex char '" + c + "'");
      }
  
      public static byte[] hexStringToByteArray(final String hexString) {
          final int length = hexString.length();
          final byte[] buffer = new byte[length / 2];
  
          for (int i = 0; i < length; i += 2) {
              buffer[i / 2] = (byte) ((toByte(hexString.charAt(i)) << 4) | toByte(hexString.charAt(i + 1)));
          }
  
          return buffer;
      }
  }