base64.java

一个类似于openJMS分布在ObjectWeb之下的JMS消息中间件。

/*
 * JORAM: Java(TM) Open Reliable Asynchronous Messaging
 * Copyright (C) 2003 - ScalAgent Distributed Technologies
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or any later version.
 * 
 * This library 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 * USA.
 *
 * The present code contributor is ScalAgent Distributed Technologies.
 *
 * Initial developer(s): Nicolas Tachker (ScalAgent)
 * Contributor(s):
 */
package com.scalagent.ksoap.marshal;

import java.io.*;

public class Base64 {
  static final char[] charTab = 
      "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".toCharArray(); 
    
  public static String encode(byte [] data) {
    return encode (data,0,data.length,null).toString();
  }

  public static StringBuffer encode(byte [] data, int start, int len, StringBuffer buf) {
    if (buf == null) 
      buf = new StringBuffer(data.length * 3 / 2);

    int end = len - 3;
    int i = start;
    int n = 0;

    while (i <= end) {
      int d = ((((int) data[i]) & 0x0ff) << 16) 
        | ((((int) data[i+1]) & 0x0ff) << 8)
        | (((int) data[i+2]) & 0x0ff);
      buf.append(charTab[(d >> 18) & 63]);
      buf.append(charTab[(d >> 12) & 63]);
      buf.append(charTab[(d >> 6) & 63]);
      buf.append(charTab[d & 63]);
      i += 3;
      if (n++ >= 14) {
        n = 0;
        buf.append("\r\n");
      }
    }

    if (i == start + len - 2) {
      int d = ((((int) data[i]) & 0x0ff) << 16) 
        | ((((int) data[i+1]) & 255) << 8);
      buf.append(charTab[(d >> 18) & 63]);
      buf.append(charTab[(d >> 12) & 63]);
      buf.append(charTab[(d >> 6) & 63]);
      buf.append("=");
    } else if (i == start + len - 1) {
      int d = (((int) data[i]) & 0x0ff) << 16;
      buf.append(charTab[(d >> 18) & 63]);
      buf.append(charTab[(d >> 12) & 63]);
      buf.append("==");
    }
    return buf;
  }

  static int decode(char c) {
    if (c >= 'A' && c <= 'Z') 
      return ((int) c) - 65;
    else if (c >= 'a' && c <= 'z') 
      return ((int) c) - 97 + 26;
    else if (c >= '0' && c <= '9')
      return ((int) c) - 48 + 26 + 26;
    else 
      switch (c) {
      case '+': return 62;
      case '/': return 63;
      case '=': return 0;
      default:
        throw new RuntimeException("unexpected code: "+c);
      }
  }
		
  public static byte [] decode(String s) {
    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    decode(s,bos);
    return bos.toByteArray();
  }

  public static void decode(String s, ByteArrayOutputStream bos) {
    int i = 0;
    int len = s.length();
    
    while (true) { 
      while (i < len && s.charAt(i) <= ' ') i++;
      if (i == len) break;
      int tri = (decode(s.charAt(i)) << 18)
        + (decode(s.charAt(i+1)) << 12)
        + (decode(s.charAt(i+2)) << 6)
        + (decode(s.charAt(i+3)));
      bos.write((tri >> 16) & 255);
      if (s.charAt (i+2) == '=') break;
      bos.write((tri >> 8) & 255);
      if (s.charAt (i+3) == '=') break;
      bos.write(tri & 255);
      i += 4;
    }
  }
}