Dumps data in hexadecimal format : Hex Oct « Data Type « Java Tutorial






/*
 * 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.
 */
import java.io.IOException;
import java.io.OutputStream;

/**
 * Dumps data in hexadecimal format.
 * 
 * Provides a single function to take an array of bytes and display it
 * in hexadecimal form.
 * 
 * Origin of code: POI.
 *
 * @author Scott Sanders
 * @author Marc Johnson
 * @version $Id: HexDump.java 596667 2007-11-20 13:50:14Z niallp $
 */
public class HexDump {

    /**
     * Instances should NOT be constructed in standard programming.
     */
    public HexDump() {
        super();
    }

    /**
     * Dump an array of bytes to an OutputStream.
     *
     * @param data  the byte array to be dumped
     * @param offset  its offset, whatever that might mean
     * @param stream  the OutputStream to which the data is to be
     *               written
     * @param index initial index into the byte array
     *
     * @throws IOException is thrown if anything goes wrong writing
     *         the data to stream
     * @throws ArrayIndexOutOfBoundsException if the index is
     *         outside the data array's bounds
     * @throws IllegalArgumentException if the output stream is null
     */

    public static void dump(byte[] data, long offset,
                            OutputStream stream, int index)
            throws IOException, ArrayIndexOutOfBoundsException,
            IllegalArgumentException {
        
        if ((index < 0) || (index >= data.length)) {
            throw new ArrayIndexOutOfBoundsException(
                    "illegal index: " + index + " into array of length "
                    + data.length);
        }
        if (stream == null) {
            throw new IllegalArgumentException("cannot write to nullstream");
        }
        long display_offset = offset + index;
        StringBuffer buffer = new StringBuffer(74);

        for (int j = index; j < data.length; j += 16) {
            int chars_read = data.length - j;

            if (chars_read > 16) {
                chars_read = 16;
            }
            dump(buffer, display_offset).append(' ');
            for (int k = 0; k < 16; k++) {
                if (k < chars_read) {
                    dump(buffer, data[k + j]);
                } else {
                    buffer.append("  ");
                }
                buffer.append(' ');
            }
            for (int k = 0; k < chars_read; k++) {
                if ((data[k + j] >= ' ') && (data[k + j] < 127)) {
                    buffer.append((char) data[k + j]);
                } else {
                    buffer.append('.');
                }
            }
            buffer.append(EOL);
            stream.write(buffer.toString().getBytes());
            stream.flush();
            buffer.setLength(0);
            display_offset += chars_read;
        }
    }

    /**
     * The line-separator (initializes to "line.separator" system property.
     */
    public static final String EOL =
            System.getProperty("line.separator");
    private static final char[] _hexcodes =
            {
                '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
                'A', 'B', 'C', 'D', 'E', 'F'
            };
    private static final int[] _shifts =
            {
                28, 24, 20, 16, 12, 8, 4, 0
            };

    /**
     * Dump a long value into a StringBuffer.
     *
     * @param _lbuffer the StringBuffer to dump the value in
     * @param value  the long value to be dumped
     * @return StringBuffer containing the dumped value.
     */
    private static StringBuffer dump(StringBuffer _lbuffer, long value) {
        for (int j = 0; j < 8; j++) {
            _lbuffer
                    .append(_hexcodes[((int) (value >> _shifts[j])) & 15]);
        }
        return _lbuffer;
    }

    /**
     * Dump a byte value into a StringBuffer.
     *
     * @param _cbuffer the StringBuffer to dump the value in
     * @param value  the byte value to be dumped
     * @return StringBuffer containing the dumped value.
     */
    private static StringBuffer dump(StringBuffer _cbuffer, byte value) {
        for (int j = 0; j < 2; j++) {
            _cbuffer.append(_hexcodes[(value >> _shifts[j + 6]) & 15]);
        }
        return _cbuffer;
    }

}








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