Base64OutputStream.java :  » Database-DBMS » Quadcap-Embeddable-Database » com » quadcap » io » Java Open Source

package com.quadcap.io;

/* Copyright 1997 - 2003 Quadcap Software.  All rights reserved.
 *
 * This software is distributed under the Quadcap Free Software License.
 * This software may be used or modified for any purpose, personal or
 * commercial.  Open Source redistributions are permitted.  Commercial
 * redistribution of larger works derived from, or works which bundle
 * this software requires a "Commercial Redistribution License"; see
 * http://www.quadcap.com/purchase.
 *
 * Redistributions qualify as "Open Source" under  one of the following terms:
 *   
 *    Redistributions are made at no charge beyond the reasonable cost of
 *    materials and delivery.
 *
 *    Redistributions are accompanied by a copy of the Source Code or by an
 *    irrevocable offer to provide a copy of the Source Code for up to three
 *    years at the cost of materials and delivery.  Such redistributions
 *    must allow further use, modification, and redistribution of the Source
 *    Code under substantially the same terms as this license.
 *
 * Redistributions of source code must retain the copyright notices as they
 * appear in each source code file, these license terms, and the
 * disclaimer/limitation of liability set forth as paragraph 6 below.
 *
 * Redistributions in binary form must reproduce this Copyright Notice,
 * these license terms, and the disclaimer/limitation of liability set
 * forth as paragraph 6 below, in the documentation and/or other materials
 * provided with the distribution.
 *
 * The Software is provided on an "AS IS" basis.  No warranty is
 * provided that the Software is free of defects, or fit for a
 * particular purpose.  
 *
 * Limitation of Liability. Quadcap Software shall not be liable
 * for any damages suffered by the Licensee or any third party resulting
 * from use of the Software.
 */

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

/**
 * A filter output stream usually, converting binary octets to their
 * base64 representation.  If no filter outputstream is specified, we
 * collect the output into a buffer and can return it via 'toString()'
 *
 * @author Stan Bailes
 */
public class Base64OutputStream extends OutputStream {
    OutputStream    out;
    int        accum;
    int        pos = 0;
    public boolean              doLineBreaks    = true;

    public static byte[]   base64 = {
  (byte)'A', (byte)'B', (byte)'C', (byte)'D',
  (byte)'E', (byte)'F', (byte)'G', (byte)'H',
  (byte)'I', (byte)'J', (byte)'K', (byte)'L',
  (byte)'M', (byte)'N', (byte)'O', (byte)'P',
  (byte)'Q', (byte)'R', (byte)'S', (byte)'T',
  (byte)'U', (byte)'V', (byte)'W', (byte)'X',
  (byte)'Y', (byte)'Z', (byte)'a', (byte)'b',
  (byte)'c', (byte)'d', (byte)'e', (byte)'f',
  (byte)'g', (byte)'h', (byte)'i', (byte)'j',
  (byte)'k', (byte)'l', (byte)'m', (byte)'n',
  (byte)'o', (byte)'p', (byte)'q', (byte)'r',
  (byte)'s', (byte)'t', (byte)'u', (byte)'v',
  (byte)'w', (byte)'x', (byte)'y', (byte)'z',
  (byte)'0', (byte)'1', (byte)'2', (byte)'3',
  (byte)'4', (byte)'5', (byte)'6', (byte)'7',
  (byte)'8', (byte)'9', (byte)'+', (byte)'/'
    };

    /**
     * Default constructor for catpure as string
     */
    public Base64OutputStream() {
        this.out = new ByteArrayOutputStream();
    }

    /**
     * Constructor for output stream chaining mode.
     */
    public Base64OutputStream(OutputStream out) {
  this.out = out;
    }

    /**
     * Write a byte.
     */
    public void write(int c) throws IOException {
  accum <<= 8;
  accum |= (c & 0xff);
  if ((++pos % 3) == 0) {
      out.write(base64[(accum >> 18) & 0x3f]);
      out.write(base64[(accum >> 12) & 0x3f]);
      out.write(base64[(accum >> 6) & 0x3f]);
      out.write(base64[(accum >> 0) & 0x3f]);
      accum = 0;
  }
  if (doLineBreaks && (pos % 54) == 0) {
      out.write('\r');
      out.write('\n');
  }
    }

    /**
     * Finish the base64 encoding operation...
     */
    public void finish() throws IOException {
  int p = pos % 3;
  if (p == 1) {
      accum <<= 16;
      out.write(base64[(accum >> 18) & 0x3f]);
      out.write(base64[(accum >> 12) & 0x3f]);
      out.write('=');
      out.write('=');
  } else if (p == 2) {
      accum <<= 8;
      out.write(base64[(accum >> 18) & 0x3f]);
      out.write(base64[(accum >> 12) & 0x3f]);
      out.write(base64[(accum >> 6) & 0x3f]);
      out.write('=');
  }
    }

    /**
     * Return a string representation, if we can
     */
    public String toString() {
        return out.toString();
    }
}