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1   /*
2    * Copyright (c) 1997, 2012, 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      public void setNameMode(String name, int mode) {
89          this.name = name;
90          this.mode = mode;
91      }
92  
93      public void write(byte[] b, int off, int len) throws IOException {
94          for (int i = 0; i < len; i++)
95              write(b[off + i]);
96      }
97  
98      public void write(byte[] data) throws IOException {
99          write(data, 0, data.length);
100     }
101 
102     public void write(int c) throws IOException {
103         /* buffer up characters till we get a line's worth, then encode
104          * and write them out. Max number of characters allowed per
105          * line is 45.
106          */
107         buffer[bufsize++] = (byte)c;
108         if (bufsize == 45) {
109             writePrefix();
110             encode();
111             bufsize = 0;
112         }
113     }
114 
115     public void flush() throws IOException {
116         if (bufsize > 0) { // If there's unencoded characters in the buffer
117             writePrefix();
118             encode();      // .. encode them
119         }
120         writeSuffix();
121         out.flush();
122     }
123 
124     public void close() throws IOException {
125         flush();
126         out.close();
127     }
128 
129     /**
130      * Write out the prefix: "begin <mode> <name>"
131      */
132     private void writePrefix() throws IOException {
133         if (!wrotePrefix) {
134             PrintStream ps = new PrintStream(out);
135             ps.println("begin " + mode + " " + name);
136             ps.flush();
137             wrotePrefix = true;
138         }
139     }
140 
141     /**
142      * Write a single line containing space and the suffix line
143      * containing the single word "end" (terminated by a newline)
144      */
145     private void writeSuffix() throws IOException {
146         PrintStream ps = new PrintStream(out);
147         ps.println(" \nend");
148         ps.flush();
149     }
150 
151     /**
152      * Encode a line.
153      * Start off with the character count, followed by the encoded atoms
154      * and terminate with LF. (or is it CRLF or the local line-terminator ?)
155      * Take three bytes and encodes them into 4 characters
156      * If bufsize if not a multiple of 3, the remaining bytes are filled
157      * with '1'. This insures that the last line won't end in spaces
158      * and potentiallly be truncated.
159      */
160     private void encode() throws IOException {
161         byte a, b, c;
162         int c1, c2, c3, c4;
163         int i = 0;
164 
165         // Start off with the count of characters in the line
166         out.write((bufsize & 0x3f) + ' ');
167 
168         while (i < bufsize) {
169             a = buffer[i++];
170             if (i < bufsize) {
171                 b = buffer[i++];
172                 if (i < bufsize)
173                     c = buffer[i++];
174                 else // default c to 1
175                     c = 1;
176             }
177             else { // default b & c to 1
178                 b = 1;
179                 c = 1;
180             }
181 
182             c1 = (a >>> 2) & 0x3f;
183             c2 = ((a << 4) & 0x30) | ((b >>> 4) & 0xf);
184             c3 = ((b << 2) & 0x3c) | ((c >>> 6) & 0x3);
185             c4 = c & 0x3f;
186             out.write(c1 + ' ');
187             out.write(c2 + ' ');
188             out.write(c3 + ' ');
189             out.write(c4 + ' ');
190         }
191         // Terminate with LF. (should it be CRLF or local line-terminator ?)
192         out.write('\n');
193     }
194 
195     /**** begin TEST program *****
196     public static void main(String argv[]) throws Exception {
197         FileInputStream infile = new FileInputStream(argv[0]);
198         UUEncoderStream encoder = new UUEncoderStream(System.out);
199         int c;
200 
201         while ((c = infile.read()) != -1)
202             encoder.write(c);
203         encoder.close();
204     }
205     **** end TEST program *****/
206 }