package org.jscsi.target.util;

 import java.nio.ByteBuffer;

 /**

  * This class provides static methods for printing the bytes of {@link ByteBuffer} objects. The individual values will

  * be printed in hexadecimal format in a tabular arrangement.

  * 

  * @author Andreas Ergenzinger, University of Konstanz

  */

 public class Debug {

     /**

      * The number of bytes to print per line.

      */

     private static final int BYTES_PER_LINE = 4;

     /**

      * Prints the <i>buffer</i> content to <code>System.out</code>.

      * 

      * @param buffer contains the bytes to print

      */

     public static void printByteBuffer (final ByteBuffer buffer) {

         System.out.println(byteBufferToString(buffer));

     }

     /**

      * Returns a string containing the buffered values in the defined format.

      * 

      * @param buffer contains the bytes to return in the {@link String}

      * @return a {@link String} with the values in tabular arrangement

      */

     public static String byteBufferToString (final ByteBuffer buffer) {

         if (buffer == null) return "null";

         final int numberOfBytes = buffer.limit();

         final StringBuilder sb = new StringBuilder();

         buffer.position(0);

         int value;

         for (int i = 1; i <= numberOfBytes; ++i) {

             sb.append("0x");

             value = 255 & buffer.get();

             if (value < 16) sb.append("0");

             sb.append(Integer.toHexString(value));

             if (i % BYTES_PER_LINE == 0)

                 sb.append("\n");

             else

                 sb.append("   ");

         }

         return sb.toString();

     }

 }