HexUtils.java

/* 
 * Copyright 2007 Colin Crist
 *
 * 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 hermes.util;

/**
 * @author colincrist@hermesjms.com
 * @version $Id$
 */



import java.io.OutputStreamWriter;
import java.io.PrintStream;
import java.io.PrintWriter;


public class HexUtils
    {
    private static final int        ROW_BYTES = 16;
    private static final int        ROW_QTR1 = 3;
    private static final int        ROW_HALF = 7;
    private static final int        ROW_QTR2 = 11;

    public static void
    dumpHexData( PrintStream out, String title, byte[] buf, int numBytes )
        {
        PrintWriter wrtr =
            new PrintWriter( new OutputStreamWriter( out ) );

        HexUtils.dumpHexData( wrtr, title, buf, 0, numBytes );
        wrtr.flush();
        }

    public static void
    dumpHexData(
            PrintWriter out, String title,
            byte[] buf, int offset, int numBytes )
        {
        int         rows, residue, i, j;
        byte[]      save_buf= new byte[ ROW_BYTES+2 ];
        char[]      hex_buf = new char[ 4 ];
        char[]      idx_buf = new char[ 8 ];
        char[]      hex_chars = new char[20];
        
        hex_chars[0] = '0';
        hex_chars[1] = '1';
        hex_chars[2] = '2';
        hex_chars[3] = '3';
        hex_chars[4] = '4';
        hex_chars[5] = '5';
        hex_chars[6] = '6';
        hex_chars[7] = '7';
        hex_chars[8] = '8';
        hex_chars[9] = '9';
        hex_chars[10] = 'A';
        hex_chars[11] = 'B';
        hex_chars[12] = 'C';
        hex_chars[13] = 'D';
        hex_chars[14] = 'E';
        hex_chars[15] = 'F';
        
        out.println( title + " - " + numBytes + " bytes." );
        rows = numBytes >> 4;
        residue = numBytes & 0x0000000F;
        for ( i = 0 ; i < rows ; i++ )
            {
            int hexVal = (i * ROW_BYTES);
            idx_buf[0] = hex_chars[ ((hexVal >> 12) & 15) ];
            idx_buf[1] = hex_chars[ ((hexVal >> 8) & 15) ];
            idx_buf[2] = hex_chars[ ((hexVal >> 4) & 15) ];
            idx_buf[3] = hex_chars[ (hexVal & 15) ];

            String idxStr = new String( idx_buf, 0, 8 );
            out.print( idxStr + ": " );
        
            for ( j = 0 ; j < ROW_BYTES ; j++ )
                {
                save_buf[j] = buf[ offset + (i * ROW_BYTES) + j ];

                hex_buf[0] = hex_chars[ (save_buf[j] >> 4) & 0x0F ];
                hex_buf[1] = hex_chars[ save_buf[j] & 0x0F ];

                out.print( hex_buf[0] );
                out.print( hex_buf[1] );
                out.print( ' ' );

                if ( j == ROW_QTR1 || j == ROW_HALF || j == ROW_QTR2 )
                    out.print( " " );

                if ( save_buf[j] < 0x20 || save_buf[j] > 0x7E )
                    save_buf[j] = (byte) '.';
                }

            String saveStr = new String( save_buf, 0, j );
            out.println( " | " + saveStr + " |" );
            }
        
        if ( residue > 0 )
            {
            int hexVal = (i * ROW_BYTES);
            idx_buf[0] = hex_chars[ ((hexVal >> 12) & 15) ];
            idx_buf[1] = hex_chars[ ((hexVal >> 8) & 15) ];
            idx_buf[2] = hex_chars[ ((hexVal >> 4) & 15) ];
            idx_buf[3] = hex_chars[ (hexVal & 15) ];

            String idxStr = new String( idx_buf, 0, 4 );
            out.print( idxStr + ": " );

            for ( j = 0 ; j < residue ; j++ )
                {
                save_buf[j] = buf[ offset + (i * ROW_BYTES) + j ];

                hex_buf[0] = hex_chars[ (save_buf[j] >> 4) & 0x0F ];
                hex_buf[1] = hex_chars[ save_buf[j] & 0x0F ];

                out.print( (char)hex_buf[0] );
                out.print( (char)hex_buf[1] );
                out.print( ' ' );

                if ( j == ROW_QTR1 || j == ROW_HALF || j == ROW_QTR2 )
                    out.print( " " );

                if ( save_buf[j] < 0x20 || save_buf[j] > 0x7E )
                    save_buf[j] = (byte) '.';
                }
                
            for ( /*j INHERITED*/ ; j < ROW_BYTES ; j++ )
                {
                save_buf[j] = (byte) ' ';
                out.print( "   " );
                if ( j == ROW_QTR1 || j == ROW_HALF || j == ROW_QTR2 )
                    out.print( " " );
                }
            
            String saveStr = new String( save_buf, 0, j );
            out.println( " | " + saveStr + " |" );
            }
        }

    static public void
    main( String[] args )
        {
        byte[] data = new byte[132];
        for ( int i = 0 ; i < 132 ; ++i ) data[i] = (byte)i;

        HexUtils.dumpHexData( System.out, "Test HexDump", data, 132 );
        System.out.println("Done") ;
        }

    }