1 /*
   2  * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 /*
  27  * @(#)UUEncoderStream.java   1.3 02/03/27
  28  */
  29 
  30 
  31 
  32 package com.sun.xml.internal.messaging.saaj.packaging.mime.util;
  33 
  34 import java.io.*;
  35 
  36 /**
  37  * This class implements a UUEncoder. It is implemented as
  38  * a FilterOutputStream, so one can just wrap this class around
  39  * any output stream and write bytes into this filter. The Encoding
  40  * is done as the bytes are written out.
  41  *
  42  * @author John Mani
  43  */
  44 
  45 public class UUEncoderStream extends FilterOutputStream {
  46     private byte[] buffer;      // cache of bytes that are yet to be encoded
  47     private int bufsize = 0;    // size of the cache
  48     private boolean wrotePrefix = false;
  49 
  50     protected String name;      // name of file
  51     protected int mode;         // permissions mode
  52 
  53     /**
  54      * Create a UUencoder that encodes the specified input stream
  55      * @param out        the output stream
  56      */
  57     public UUEncoderStream(OutputStream out) {
  58         this(out, "encoder.buf", 644);
  59     }
  60 
  61     /**
  62      * Create a UUencoder that encodes the specified input stream
  63      * @param out        the output stream
  64      * @param name       Specifies a name for the encoded buffer
  65      */
  66     public UUEncoderStream(OutputStream out, String name) {
  67         this(out, name, 644);
  68     }
  69 
  70     /**
  71      * Create a UUencoder that encodes the specified input stream
  72      * @param out        the output stream
  73      * @param name       Specifies a name for the encoded buffer
  74      * @param mode       Specifies permission mode for the encoded buffer
  75      */
  76     public UUEncoderStream(OutputStream out, String name, int mode) {
  77         super(out);
  78         this.name = name;
  79         this.mode = mode;
  80         buffer = new byte[45];
  81     }
  82 
  83     /**
  84      * Set up the buffer name and permission mode.
  85      * This method has any effect only if it is invoked before
  86      * you start writing into the output stream.
  87      *
  88      * @param name name to set for the buffer.
  89      * @param mode permission mode.
  90      */
  91     public void setNameMode(String name, int mode) {
  92         this.name = name;
  93         this.mode = mode;
  94     }
  95 
  96     @Override
  97     public void write(byte[] b, int off, int len) throws IOException {
  98         for (int i = 0; i < len; i++)
  99             write(b[off + i]);
 100     }
 101 
 102     @Override
 103     public void write(byte[] data) throws IOException {
 104         write(data, 0, data.length);
 105     }
 106 
 107     @Override
 108         public void write(int c) throws IOException {
 109         /* buffer up characters till we get a line's worth, then encode
 110          * and write them out. Max number of characters allowed per
 111          * line is 45.
 112          */
 113         buffer[bufsize++] = (byte)c;
 114         if (bufsize == 45) {
 115             writePrefix();
 116             encode();
 117             bufsize = 0;
 118         }
 119     }
 120 
 121     @Override
 122     public void flush() throws IOException {
 123         if (bufsize > 0) { // If there's unencoded characters in the buffer
 124             writePrefix();
 125             encode();      // .. encode them
 126         }
 127         writeSuffix();
 128         out.flush();
 129     }
 130 
 131     @Override
 132     public void close() throws IOException {
 133         flush();
 134         out.close();
 135     }
 136 
 137     /**
 138      * Write out the prefix: "begin <mode> <name>"
 139      */
 140     private void writePrefix() throws IOException {
 141         if (!wrotePrefix) {
 142             PrintStream ps = new PrintStream(out);
 143             ps.println("begin " + mode + " " + name);
 144             ps.flush();
 145             wrotePrefix = true;
 146         }
 147     }
 148 
 149     /**
 150      * Write a single line containing space and the suffix line
 151      * containing the single word "end" (terminated by a newline)
 152      */
 153     private void writeSuffix() throws IOException {
 154         PrintStream ps = new PrintStream(out);
 155         ps.println(" \nend");
 156         ps.flush();
 157     }
 158 
 159     /**
 160      * Encode a line.
 161      * Start off with the character count, followed by the encoded atoms
 162      * and terminate with LF. (or is it CRLF or the local line-terminator ?)
 163      * Take three bytes and encodes them into 4 characters
 164      * If bufsize if not a multiple of 3, the remaining bytes are filled
 165      * with '1'. This insures that the last line won't end in spaces
 166      * and potentiallly be truncated.
 167      */
 168     private void encode() throws IOException {
 169         byte a, b, c;
 170         int c1, c2, c3, c4;
 171         int i = 0;
 172 
 173         // Start off with the count of characters in the line
 174         out.write((bufsize & 0x3f) + ' ');
 175 
 176         while (i < bufsize) {
 177             a = buffer[i++];
 178             if (i < bufsize) {
 179                 b = buffer[i++];
 180                 if (i < bufsize)
 181                     c = buffer[i++];
 182                 else // default c to 1
 183                     c = 1;
 184             }
 185             else { // default b & c to 1
 186                 b = 1;
 187                 c = 1;
 188             }
 189 
 190             c1 = (a >>> 2) & 0x3f;
 191             c2 = ((a << 4) & 0x30) | ((b >>> 4) & 0xf);
 192             c3 = ((b << 2) & 0x3c) | ((c >>> 6) & 0x3);
 193             c4 = c & 0x3f;
 194             out.write(c1 + ' ');
 195             out.write(c2 + ' ');
 196             out.write(c3 + ' ');
 197             out.write(c4 + ' ');
 198         }
 199         // Terminate with LF. (should it be CRLF or local line-terminator ?)
 200         out.write('\n');
 201     }
 202 
 203     /**** begin TEST program *****
 204     public static void main(String argv[]) throws Exception {
 205         FileInputStream infile = new FileInputStream(argv[0]);
 206         UUEncoderStream encoder = new UUEncoderStream(System.out);
 207         int c;
 208 
 209         while ((c = infile.read()) != -1)
 210             encoder.write(c);
 211         encoder.close();
 212     }
 213     **** end TEST program *****/
 214 }