Java Hex Dump hexDump(InputStream is, OutputStream os)

Description

Writes a hex dump representation of input data to the output stream.

License

Open Source License

Parameter

Parameter	Description
is	Input data assumed binary data.
os	Output that receives formatted dump.

Exception

Parameter	Description
IOException	an exception

Declaration

public static void hexDump(InputStream is, OutputStream os) throws IOException 

Method Source Code

//package com.java2s;
//License from project: Open Source License 

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class Main {
    private static final int HEXFIELDSIZE = 49;
    private static final char[] hexChars = "0123456789ABCDEF".toCharArray();

    /**//  w w w.  ja v a2 s.  com
     * Writes a hex dump representation of input data to the output stream.
     * @param is Input data assumed binary data.
     * @param os Output that receives formatted dump.
     * @throws IOException
     */
    public static void hexDump(InputStream is, OutputStream os) throws IOException {
        int offset = 0;

        ByteArrayOutputStream hexStream;
        ByteArrayOutputStream asciiStream;
        while (true) {
            hexStream = new ByteArrayOutputStream();
            asciiStream = new ByteArrayOutputStream();
            int count = getHexSegment(is, hexStream, asciiStream);
            if (count <= 0)
                break;
            // Write Hex offset string as first 4 chars of line
            StringBuffer startLine = new StringBuffer("0000: ");
            String offsetStr = Integer.toHexString(offset & 0xffff).toUpperCase();
            startLine.replace(4 - offsetStr.length(), 4, offsetStr);
            os.write(startLine.toString().getBytes());
            byte[] hexField = hexStream.toByteArray();
            os.write(hexField);
            for (int i = 0; i < HEXFIELDSIZE - hexField.length; i++) {
                os.write(' ');
            }
            os.write("  |".getBytes());
            os.write(asciiStream.toByteArray());
            os.write('\n');
            offset += 16;
        }
    }

    /**
     * Interprets up to 16 bytes of input data and writes formatted dump data.
     *
     * @param is Input data stream
     * @param hexStream Output for hex data written as 8 bit data bytes represented
     * as ascii hex.
     * @param asciiStream Ascii output for the input data. If input is not a printable
     * ascii character, a '.' is output.
     * @return Number of bytes processed.
     * @throws IOException
     */
    public static int getHexSegment(InputStream is, OutputStream hexStream, OutputStream asciiStream)
            throws IOException {
        int count = 0;
        int val;

        for (int i = 0; i < 2; i++) {
            for (int j = 0; j < 8; j++) {
                val = is.read();
                if (val < 0)
                    return count;
                putHex(val, hexStream);
                putAscii(val, asciiStream);
                count++;
                if (j != 7)
                    hexStream.write(' ');
            }
            if (i == 0) {
                hexStream.write(' ');
                hexStream.write('-');
                hexStream.write(' ');
            }
        }
        return count;
    }

    public static void putHex(int val, OutputStream out) throws IOException {
        out.write(hexChars[(val & 0xf0) >> 4]);
        out.write(hexChars[val & 0xf]);
    }

    public static void putAscii(int c, OutputStream out) throws IOException {
        if ((c >= ' ') && (c <= '~'))
            out.write(c);
        else
            out.write('.');
    }
}

Related

1. hexdump(byte[] bytes, OutputStream out)
2. hexDump(byte[] data)
3. hexDump(InputStream is, PrintStream ps, int maxRead, int bytesPerLine)
4. hexDump(PrintStream out, String s, byte b[], int n)
5. hexDump(String prompt, byte[] bs)
6. hexDumpBytes(PrintStream out, long offset, byte[] bytes)