Java ByteBuffer Dump dumpAsHex(byte[] byteBuffer, int length)

Description

Dumps the given bytes to STDOUT as a hex dump (up to length bytes).

License

Open Source License

Parameter

Parameter	Description
byteBuffer	the data to print as hex
length	the number of bytes to print

Return

...

Declaration

public static String dumpAsHex(byte[] byteBuffer, int length) 

Method Source Code

//package com.java2s;
/*/*w  w  w .  j  av  a  2  s . c  o  m*/
 Copyright (c) 2002, 2014, Oracle and/or its affiliates. All rights reserved.

 The MySQL Connector/J is licensed under the terms of the GPLv2
 <http://www.gnu.org/licenses/old-licenses/gpl-2.0.html>, like most MySQL Connectors.
 There are special exceptions to the terms and conditions of the GPLv2 as it is applied to
 this software, see the FLOSS License Exception
 <http://www.mysql.com/about/legal/licensing/foss-exception.html>.

 This program is free software; you can redistribute it and/or modify it under the terms
 of the GNU General Public License as published by the Free Software Foundation; version 2
 of the License.

 This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 See the GNU General Public License for more details.

 You should have received a copy of the GNU General Public License along with this
 program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth
 Floor, Boston, MA 02110-1301  USA

 */

import java.io.UnsupportedEncodingException;

import java.nio.ByteBuffer;

import java.nio.charset.Charset;
import java.nio.charset.IllegalCharsetNameException;
import java.nio.charset.UnsupportedCharsetException;

import java.util.concurrent.ConcurrentHashMap;

public class Main {
    private static final ConcurrentHashMap<String, Charset> charsetsByAlias = new ConcurrentHashMap<String, Charset>();
    private static final String platformEncoding = System
            .getProperty("file.encoding");

    /**
     * Dumps the given bytes to STDOUT as a hex dump (up to length bytes).
     * 
     * @param byteBuffer
     *            the data to print as hex
     * @param length
     *            the number of bytes to print
     * 
     * @return ...
     */
    public static String dumpAsHex(byte[] byteBuffer, int length) {
        StringBuilder outputBuilder = new StringBuilder(length * 4);

        int p = 0;
        int rows = length / 8;

        for (int i = 0; (i < rows) && (p < length); i++) {
            int ptemp = p;

            for (int j = 0; j < 8; j++) {
                String hexVal = Integer
                        .toHexString(byteBuffer[ptemp] & 0xff);

                if (hexVal.length() == 1) {
                    hexVal = "0" + hexVal;
                }

                outputBuilder.append(hexVal + " ");
                ptemp++;
            }

            outputBuilder.append("    ");

            for (int j = 0; j < 8; j++) {
                int b = 0xff & byteBuffer[p];

                if (b > 32 && b < 127) {
                    outputBuilder.append((char) b + " ");
                } else {
                    outputBuilder.append(". ");
                }

                p++;
            }

            outputBuilder.append("\n");
        }

        int n = 0;

        for (int i = p; i < length; i++) {
            String hexVal = Integer.toHexString(byteBuffer[i] & 0xff);

            if (hexVal.length() == 1) {
                hexVal = "0" + hexVal;
            }

            outputBuilder.append(hexVal + " ");
            n++;
        }

        for (int i = n; i < 8; i++) {
            outputBuilder.append("   ");
        }

        outputBuilder.append("    ");

        for (int i = p; i < length; i++) {
            int b = 0xff & byteBuffer[i];

            if (b > 32 && b < 127) {
                outputBuilder.append((char) b + " ");
            } else {
                outputBuilder.append(". ");
            }
        }

        outputBuilder.append("\n");

        return outputBuilder.toString();
    }

    public static String toString(byte[] value, int offset, int length,
            String encoding) throws UnsupportedEncodingException {
        Charset cs = findCharset(encoding);

        return cs.decode(ByteBuffer.wrap(value, offset, length)).toString();
    }

    public static String toString(byte[] value, String encoding)
            throws UnsupportedEncodingException {
        Charset cs = findCharset(encoding);

        return cs.decode(ByteBuffer.wrap(value)).toString();
    }

    public static String toString(byte[] value, int offset, int length) {
        try {
            Charset cs = findCharset(platformEncoding);

            return cs.decode(ByteBuffer.wrap(value, offset, length))
                    .toString();
        } catch (UnsupportedEncodingException e) {
            // can't happen, emulating new String(byte[])
        }

        return null;
    }

    public static String toString(byte[] value) {
        try {
            Charset cs = findCharset(platformEncoding);

            return cs.decode(ByteBuffer.wrap(value)).toString();
        } catch (UnsupportedEncodingException e) {
            // can't happen, emulating new String(byte[])
        }

        return null;
    }

    static Charset findCharset(String alias)
            throws UnsupportedEncodingException {
        try {
            Charset cs = charsetsByAlias.get(alias);

            if (cs == null) {
                cs = Charset.forName(alias);
                charsetsByAlias.putIfAbsent(alias, cs);
            }

            return cs;

            // We re-throw these runtimes for compatibility with java.io
        } catch (UnsupportedCharsetException uce) {
            throw new UnsupportedEncodingException(alias);
        } catch (IllegalCharsetNameException icne) {
            throw new UnsupportedEncodingException(alias);
        } catch (IllegalArgumentException iae) {
            throw new UnsupportedEncodingException(alias);
        }
    }
}

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6. dumpBoolean(ByteBuffer itemBuffer, StringBuilder sb, String tag)
7. dumpBytes(ByteBuffer bbuf)
8. dumpBytes(ByteBuffer byteBuffer)
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