dump an array of bytes in hex form : Hex Oct « Data Type « Java Tutorial

import java.io.File;
import java.io.FileFilter;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;

/*
 *  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. 
 *  
 */



/**
 * Various string manipulation methods that are more efficient then chaining
 * string operations: all is done in the same buffer without creating a bunch of
 * string objects.
 * 
 * @author <a href="mailto:dev@labs.apache.org">Dungeon Project</a>
 */
public class Main {
  /** Hex chars */
  private static final byte[] HEX_CHAR = new byte[]
      { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };


  /**
   * Helper function that dump an array of bytes in hex form
   * 
   * @param buffer
   *            The bytes array to dump
   * @return A string representation of the array of bytes
   */
  public static final String dumpBytes( byte[] buffer )
  {
      if ( buffer == null )
      {
          return "";
      }

      StringBuffer sb = new StringBuffer();

      for ( int i = 0; i < buffer.length; i++ )
      {
          sb.append( "0x" ).append( ( char ) ( HEX_CHAR[( buffer[i] & 0x00F0 ) >> 4] ) ).append(
              ( char ) ( HEX_CHAR[buffer[i] & 0x000F] ) ).append( " " );
      }

      return sb.toString();
  }

}

2.9.Hex Oct
	2.9.1.	Hexadecimal integer literal
	2.9.2.	A hexadecimal literal of type long
	2.9.3.	Defining integer literals as octal values
	2.9.4.	Decode string to integer
	2.9.5.	Convert octal number to decimal number example
	2.9.6.	Convert decimal integer to octal number example
	2.9.7.	Convert decimal integer to hexadecimal number example
	2.9.8.	Parsing and Formatting a Number into Binary
	2.9.9.	Convert byte array to Hex String
	2.9.10.	Convert the bytes to a hex string representation of the bytes
	2.9.11.	Converting hexadecimal strings
	2.9.12.	Dumps data in hexadecimal format
	2.9.13.	Given a hexstring this will return the byte array corresponding to string
	2.9.14.	Hex encoder/decoder implementation borrowed from BouncyCastle
	2.9.15.	Returns the hexadecimal value of the supplied byte array
	2.9.16.	A custom number formatter that formats numbers as hexadecimal strings.
	2.9.17.	Decodes Hex data into octects
	2.9.18.	Decodes Base64 data into octects
	2.9.19.	Helper function that returns a char from an hex
	2.9.20.	Encodes hex octects into Base64
	2.9.21.	Hex encoder and decoder.
	2.9.22.	Helper function that dump an array of bytes in hex pair form, without '0x' and space chars
	2.9.23.	dump an array of bytes in hex form
	2.9.24.	Decode byte array