content: package local.org.bouncycastle.util.encoders;
  
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.io.OutputStream;
  
  import local.org.bouncycastle.util.Strings;
  
  
  public class Hex
  {
      private static final Encoder encoder = new HexEncoder();
      
      public static String toHexString(
          byte[] data)
      {
          return toHexString(data, 0, data.length);
      }
  
      public static String toHexString(
          byte[] data,
          int    off,
          int    length)
      {
          byte[] encoded = encode(data, off, length);
          return Strings.fromByteArray(encoded);
      }
  
      /**
       * encode the input data producing a Hex encoded byte array.
       *
       * @return a byte array containing the Hex encoded data.
       */
      public static byte[] encode(
          byte[]    data)
      {
          return encode(data, 0, data.length);
      }
      
      /**
       * encode the input data producing a Hex encoded byte array.
       *
       * @return a byte array containing the Hex encoded data.
       */
      public static byte[] encode(
          byte[]    data,
          int       off,
          int       length)
      {
          ByteArrayOutputStream    bOut = new ByteArrayOutputStream();
          
          try
          {
              encoder.encode(data, off, length, bOut);
          }
          catch (Exception e)
          {
              throw new EncoderException("exception encoding Hex string: " + e.getMessage(), e);
          }
          
          return bOut.toByteArray();
      }
  
      /**
       * Hex encode the byte data writing it to the given output stream.
       *
       * @return the number of bytes produced.
       */
      public static int encode(
          byte[]         data,
          OutputStream   out)
          throws IOException
      {
          return encoder.encode(data, 0, data.length, out);
      }
      
      /**
       * Hex encode the byte data writing it to the given output stream.
       *
       * @return the number of bytes produced.
       */
      public static int encode(
          byte[]         data,
          int            off,
          int            length,
          OutputStream   out)
          throws IOException
      {
          return encoder.encode(data, off, length, out);
      }
      
      /**
       * decode the Hex encoded input data. It is assumed the input data is valid.
       *
       * @return a byte array representing the decoded data.
       */
      public static byte[] decode(
          byte[]    data)
      {
          ByteArrayOutputStream    bOut = new ByteArrayOutputStream();
          
          try
          {
              encoder.decode(data, 0, data.length, bOut);
          }
          catch (Exception e)
          {
              throw new DecoderException("exception decoding Hex data: " + e.getMessage(), e);
          }
          
          return bOut.toByteArray();
      }
      
      /**
       * decode the Hex encoded String data - whitespace will be ignored.
       *
       * @return a byte array representing the decoded data.
       */
      public static byte[] decode(
          String    data)
      {
          ByteArrayOutputStream    bOut = new ByteArrayOutputStream();
          
          try
          {
              encoder.decode(data, bOut);
          }
          catch (Exception e)
          {
              throw new DecoderException("exception decoding Hex string: " + e.getMessage(), e);
          }
          
          return bOut.toByteArray();
      }
      
      /**
       * decode the Hex encoded String data writing it to the given output stream,
       * whitespace characters will be ignored.
       *
       * @return the number of bytes produced.
       */
      public static int decode(
          String          data,
          OutputStream    out)
          throws IOException
      {
          return encoder.decode(data, out);
      }
  }
  