Hexdump.java

/*
 * Java Hexdump Library
 *
 * Copyright (c) Matthew Johnson 2005
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 * 
 * To Contact the author, please email src@matthew.ath.cx
 *
 */

package cx.ath.matthew.utils;

import java.io.PrintStream;

public class Hexdump {
    public static final char[] hexchars = new char[]{'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};

    public static String toHex(byte[] buf) {
        return toHex(buf, 0, buf.length);
    }

    public static String toHex(byte[] buf, int ofs, int len) {
        StringBuffer sb = new StringBuffer();
        int j = ofs + len;
        for (int i = ofs; i < j; i++) {
            if (i < buf.length) {
                sb.append(hexchars[(buf[i] & 0xF0) >> 4]);
                sb.append(hexchars[buf[i] & 0x0F]);
                sb.append(' ');
            } else {
                sb.append(' ');
                sb.append(' ');
                sb.append(' ');
            }
        }
        return sb.toString();
    }

    public static String toAscii(byte[] buf) {
        return toAscii(buf, 0, buf.length);
    }

    public static String toAscii(byte[] buf, int ofs, int len) {
        StringBuffer sb = new StringBuffer();
        int j = ofs + len;
        for (int i = ofs; i < j; i++) {
            if (i < buf.length) {
                if (20 <= buf[i] && 126 >= buf[i])
                    sb.append((char) buf[i]);
                else
                    sb.append('.');
            } else
                sb.append(' ');
        }
        return sb.toString();
    }

    public static String format(byte[] buf) {
        return format(buf, 80);
    }

    public static String format(byte[] buf, int width) {
        int bs = (width - 8) / 4;
        int i = 0;
        StringBuffer sb = new StringBuffer();
        do {
            for (int j = 0; j < 6; j++) {
                sb.append(hexchars[(i << (j * 4) & 0xF00000) >> 20]);
            }
            sb.append('\t');
            sb.append(toHex(buf, i, bs));
            sb.append(' ');
            sb.append(toAscii(buf, i, bs));
            sb.append('\n');
            i += bs;
        } while (i < buf.length);
        return sb.toString();
    }

    public static void print(byte[] buf) {
        print(buf, System.err);
    }

    public static void print(byte[] buf, int width) {
        print(buf, width, System.err);
    }

    public static void print(byte[] buf, int width, PrintStream out) {
        out.print(format(buf, width));
    }

    public static void print(byte[] buf, PrintStream out) {
        out.print(format(buf));
    }

    /**
     * Returns a string which can be written to a Java source file as part
     * of a static initializer for a byte array.
     * Returns data in the format 0xAB, 0xCD, ....
     * use like:
     * javafile.print("byte[] data = {")
     * javafile.print(Hexdump.toByteArray(data));
     * javafile.println("};");
     */
    public static String toByteArray(byte[] buf) {
        return toByteArray(buf, 0, buf.length);
    }

    /**
     * Returns a string which can be written to a Java source file as part
     * of a static initializer for a byte array.
     * Returns data in the format 0xAB, 0xCD, ....
     * use like:
     * javafile.print("byte[] data = {")
     * javafile.print(Hexdump.toByteArray(data));
     * javafile.println("};");
     */
    public static String toByteArray(byte[] buf, int ofs, int len) {
        StringBuffer sb = new StringBuffer();
        for (int i = ofs; i < len && i < buf.length; i++) {
            sb.append('0');
            sb.append('x');
            sb.append(hexchars[(buf[i] & 0xF0) >> 4]);
            sb.append(hexchars[buf[i] & 0x0F]);
            if ((i + 1) < len && (i + 1) < buf.length)
                sb.append(',');
        }
        return sb.toString();
    }
}