Hex.java Source code

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Here is the source code for Hex.java

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/*************************************************************************
 *
 * ADOBE CONFIDENTIAL
 * __________________
 *
 *  Copyright 2002 - 2007 Adobe Systems Incorporated
 *  All Rights Reserved.
 *
 * NOTICE:  All information contained herein is, and remains
 * the property of Adobe Systems Incorporated and its suppliers,
 * if any.  The intellectual and technical concepts contained
 * herein are proprietary to Adobe Systems Incorporated
 * and its suppliers and may be covered by U.S. and Foreign Patents,
 * patents in process, and are protected by trade secret or copyright law.
 * Dissemination of this information or reproduction of this material
 * is strictly forbidden unless prior written permission is obtained
 * from Adobe Systems Incorporated.
 **************************************************************************/
//package flex.messaging.util;

/**
 * Code to read and write Base64-encoded text.
 * Fairly special-purpose, not quite ready for
 * general streaming as they don't let you
 * drain less than everything that is currently
 * available.
 * 
 * @exclude
 */
public class Hex {
    private static final char digits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D',
            'E', 'F' };

    public static class Decoder {
        private int filled = 0;
        private byte data[];
        private int work[] = { 0, 0 };

        public Decoder() {
            data = new byte[256];
        }

        public void decode(String encoded) {

            int estimate = 1 + encoded.length() / 2;

            if (filled + estimate > data.length) {
                int length = data.length * 2;
                while (length < filled + estimate) {
                    length *= 2;
                }
                byte[] newdata = new byte[length];

                System.arraycopy(data, 0, newdata, 0, filled);
                data = newdata;
            }

            for (int i = 0; i < encoded.length(); ++i) {
                work[0] = Character.digit(encoded.charAt(i), 16);
                i++;
                work[1] = Character.digit(encoded.charAt(i), 16);
                data[filled++] = (byte) (((work[0] << 4) | (work[1])) & 0xff);
            }
        }

        public byte[] drain() {
            byte[] r = new byte[filled];
            System.arraycopy(data, 0, r, 0, filled);
            filled = 0;
            return r;
        }

        public byte[] flush() throws IllegalStateException {
            return drain();
        }

        public void reset() {
            filled = 0;
        }

    }

    public static class Encoder {
        private StringBuffer output;

        public Encoder(int size) {
            output = new StringBuffer(size * 2);
        }

        private void encodeBlock(byte work) {
            output.append(digits[(work & 0xF0) >>> 4]);
            output.append(digits[(work & 0x0F)]);
        }

        public void encode(byte[] data) {
            encode(data, 0, data.length);
        }

        public void encode(byte[] data, int offset, int length) {
            int plainIndex = offset;

            while (plainIndex < (offset + length)) {
                encodeBlock(data[plainIndex]);
                plainIndex++;
            }
        }

        public String drain() {
            String r = output.toString();
            output.setLength(0);
            return r;
        }

        public String flush() {
            return drain();
        }
    }

    public static void main(String[] args) {
        boolean printData = false;
        int randomLimit = 500;

        for (int myCount = 0; myCount < 10000; myCount++) {
            byte raw[] = new byte[(int) (Math.random() * randomLimit)];

            for (int i = 0; i < raw.length; ++i) {
                if ((i % 1024) < 256)
                    raw[i] = (byte) (i % 1024);
                else
                    raw[i] = (byte) ((int) (Math.random() * 255) - 128);
            }
            Hex.Encoder encoder = new Hex.Encoder(100);
            encoder.encode(raw);

            String encoded = encoder.drain();

            Hex.Decoder decoder = new Hex.Decoder();
            decoder.decode(encoded);
            byte check[] = decoder.flush();

            String mesg = "Success!";
            if (check.length != raw.length) {
                mesg = "***** length mismatch!";
            } else {
                for (int i = 0; i < check.length; ++i) {
                    if (check[i] != raw[i]) {
                        mesg = "***** data mismatch!";
                        break;
                    }
                }
            }
            if (mesg.indexOf("Success") == -1) {
                System.out.println(mesg + myCount);
                break;
            }

            if (printData) {
                System.out.println("Decoded: " + new String(raw));
                System.out.println("Encoded: " + encoded);
                System.out.println("Decoded: " + new String(check));
            }
        }
    }
}