hexformatter.java

用于Java 组件和通过Windows COM 对象或Windows DLL 来公开的组件之间的互操作

//******************************************************************
// Released under the DevelopMentor OpenSource Software License.
// Please consult the LICENSE file in the project root directory,
// or at http://www.develop.com for details before using this
// software.
//******************************************************************

package com.develop.util;

/**
 * Helper class for doing hex dumps of arrays to String.  Useful for 
 * debugging, esp. on IDEs that are not hex-friendly.
 */
public class HexFormatter {

  public static String convertBytesToString(byte[] bytes) 
  {
    return convertBytesToString(bytes, 16, true);
  }

  public static String convertBytesToString(byte[] bytes, int lineLength, boolean showChars) {
    if (bytes == null) {
      return "(null array)";
    }
    return convertBytesToString(bytes, 0, bytes.length, lineLength, showChars);
  }

  public static String convertBytesToString(byte[] bytes, 
					    int startOffset, 
					    int endOffset,
					    int lineLength,
					    boolean showChars) {
    if (bytes == null) {
      return "(null array)";
    }
    int loop = 0;
    //each byte creates 3-4 chars in the  string, so the *5 makes a 
    //buffer that is large enough
    StringBuffer strb = new StringBuffer(bytes.length*5);
    int boundary = (startOffset + lineLength - 1) % lineLength;
    int charLoop = 0;
    for (charLoop = loop = startOffset; loop < endOffset; loop++) {
      strb.append(getHexString(bytes[loop]));
      if ((loop % lineLength) == boundary) 
	{
	  if (showChars) 
	    {
	      strb.append(' ');
	      while (charLoop <= loop)    
		{
		  strb.append(printChars[bytes[charLoop] & 0x00ff]);
		  charLoop++;
		}
	    }
	  strb.append("\r\n");
	}
    }

    // Added this code to print chars of last line.
    if ( showChars && ( charLoop < loop ) ) {
      for ( int gap = loop%lineLength; gap < lineLength; ++gap ) {
	strb.append("   ");
      }
      strb.append(' ');
      while ( charLoop < loop ) {
	strb.append( printChars[bytes[charLoop] & 0x00ff] );
	charLoop++;
      }
    }

    return strb.toString();
  }
    
  public final static char[] hexchars = new char[16];
  public final static char[] printChars = new char[256];
  static 
  {
    for (char n=0; n<10; n++)
      hexchars[n] = (char) ('0' +  n);
    for (char n=10; n<16; n++)  
      hexchars[n] = (char) ('A' - 10 + n);
    for (char n=0; n<32; n++)
      printChars[n] = '.';
    for (char n=32; n<256; n++)
      printChars[n] = (char) n;
    //for (char n=128; n<256; n++)
    //  printChars[n] = '.';
  }   
        
  public static char[] getHexString(byte b) {
    char[] result = new char[3];
    result[0] = hexchars[(b & 0x00f0) >> 4];
    result[1] = hexchars[b & 0x000f];
    result[2] = ' ';
    return result;
  }

}