Java Byte Array Encode encode(byte[] buffer, int offset, int len, Writer out)

Description

encode

License

Open Source License

Declaration

public static void encode(byte[] buffer, int offset, int len, Writer out) throws IOException 

Method Source Code

//package com.java2s;
/*//from ww  w  .  ja  v  a2  s. com
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

import java.io.*;

public class Main {
    private static final char ENCODE[] = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N',
            'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i',
            'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3',
            '4', '5', '6', '7', '8', '9', '+', '/' };
    private static final char CHAR_PAD = '=';

    /**
     * Encodes the data on the given {@code InputStream} as base64 and writes it
     * to the given {@code Writer}.
     *
     * @exception   IOException
     *          if an I/O error ocurrs
     */
    public static void encode(InputStream in, Writer out) throws IOException {

        OUTER: while (true) {
            int pad = 0;
            int atom = 0;

            // Read in 3 8-bit bytes
            for (int i = 0; i < 3; i++) {
                int b = in.read();

                if (b == -1) {
                    if (i == 0) {
                        break OUTER;
                    }
                    pad++;
                } else {
                    atom |= b;
                }
                atom <<= 8;
            }

            // Output 4 6-bit characters...
            for (int i = 0; i < 4 - pad; i++) {
                int index = (atom & 0xFC000000) >>> 26;
                out.write(ENCODE[index]);
                atom <<= 6;
            }

            // ...plus any padding if 3 bytes couldn't be read
            for (int i = 0; i < pad; i++) {
                out.write(CHAR_PAD);
            }
        }

        out.flush();
    }

    public static void encode(byte[] buffer, int offset, int len, Writer out) throws IOException {

        ByteArrayInputStream in = new ByteArrayInputStream(buffer, offset, len);
        encode(in, out);
    }

    public static void encode(byte[] buffer, Writer out) throws IOException {
        encode(buffer, 0, buffer.length, out);
    }

    public static void encode(String s, Writer out) throws IOException {
        encode(s.getBytes(), out);
    }

    public static String encode(byte[] buffer, int offset, int len) {
        StringWriter out = new StringWriter();
        try {
            encode(buffer, offset, len, out);
            return out.toString();
        } catch (IOException e) {
            // Not likely -- output is from a byte array to a String
        }

        return null;
    }

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

    public static String encode(String s) {
        return encode(s.getBytes());
    }
}

Related

1. encode(byte[] b)
2. encode(byte[] buf)
3. encode(byte[] buff)
4. encode(byte[] bytes)
5. encode(byte[] bytes, boolean withNewLines)
6. encode(byte[] data)
7. encode(byte[] data)