1 /*

     2  * Copyright (c) 1997, 2013, 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  * @(#)QPEncoderStream.java   1.6 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 Quoted Printable Encoder. 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 QPEncoderStream extends FilterOutputStream {

    46     private int count = 0;      // number of bytes that have been output

    47     private int bytesPerLine;   // number of bytes per line

    48     private boolean gotSpace = false;

    49     private boolean gotCR = false;

    50 

    51     /**

    52      * Create a QP encoder that encodes the specified input stream

    53      * @param out        the output stream

    54      * @param bytesPerLine  the number of bytes per line. The encoder

    55      *                   inserts a CRLF sequence after this many number

    56      *                   of bytes.

    57      */

    58     public QPEncoderStream(OutputStream out, int bytesPerLine) {

    59         super(out);

    60         // Subtract 1 to account for the '=' in the soft-return

    61         // at the end of a line

    62         this.bytesPerLine = bytesPerLine - 1;

    63     }

    64 

    65     /**

    66      * Create a QP encoder that encodes the specified input stream.

    67      * Inserts the CRLF sequence after outputting 76 bytes.

    68      * @param out        the output stream

    69      */

    70     public QPEncoderStream(OutputStream out) {

    71         this(out, 76);

    72     }

    73 

    74     /**

    75      * Encodes <code>len</code> bytes from the specified

    76      * <code>byte</code> array starting at offset <code>off</code> to

    77      * this output stream.

    78      *

    79      * @param      b     the data.

    80      * @param      off   the start offset in the data.

    81      * @param      len   the number of bytes to write.

    82      * @exception  IOException  if an I/O error occurs.

    83      */

    84     public void write(byte[] b, int off, int len) throws IOException {

    85         for (int i = 0; i < len; i++)

    86             write(b[off + i]);

    87     }

    88 

    89     /**

    90      * Encodes <code>b.length</code> bytes to this output stream.

    91      * @param      b   the data to be written.

    92      * @exception  IOException  if an I/O error occurs.

    93      */

    94     public void write(byte[] b) throws IOException {

    95         write(b, 0, b.length);

    96     }

    97 

    98     /**

    99      * Encodes the specified <code>byte</code> to this output stream.

   100      * @param      c   the <code>byte</code>.

   101      * @exception  IOException  if an I/O error occurs.

   102      */

   103     public void write(int c) throws IOException {

   104         c = c & 0xff; // Turn off the MSB.

   105         if (gotSpace) { // previous character was <SPACE>

   106             if (c == '\r' || c == '\n')

   107                 // if CR/LF, we need to encode the <SPACE> char

   108                 output(' ', true);

   109             else // no encoding required, just output the char

   110                 output(' ', false);

   111             gotSpace = false;

   112         }

   113 

   114         if (c == '\r') {

   115             gotCR = true;

   116             outputCRLF();

   117         } else {

   118             if (c == '\n') {

   119                 if (gotCR)

   120                     // This is a CRLF sequence, we already output the

   121                     // corresponding CRLF when we got the CR, so ignore this

   122                     ;

   123                 else

   124                     outputCRLF();

   125             } else if (c == ' ') {

   126                 gotSpace = true;

   127             } else if (c < 040 || c >= 0177 || c == '=')

   128                 // Encoding required.

   129                 output(c, true);

   130             else // No encoding required

   131                 output(c, false);

   132             // whatever it was, it wasn't a CR

   133             gotCR = false;

   134         }

   135     }

   136 

   137     /**

   138      * Flushes this output stream and forces any buffered output bytes

   139      * to be encoded out to the stream.

   140      * @exception  IOException  if an I/O error occurs.

   141      */

   142     public void flush() throws IOException {

   143         out.flush();

   144     }

   145 

   146     /**

   147      * Forces any buffered output bytes to be encoded out to the stream

   148      * and closes this output stream

   149      */

   150     public void close() throws IOException {

   151         out.close();

   152     }

   153 

   154     private void outputCRLF() throws IOException {

   155         out.write('\r');

   156         out.write('\n');

   157         count = 0;

   158     }

   159 

   160     // The encoding table

   161     private final static char hex[] = {

   162         '0','1', '2', '3', '4', '5', '6', '7',

   163         '8','9', 'A', 'B', 'C', 'D', 'E', 'F'

   164     };

   165 

   166     protected void output(int c, boolean encode) throws IOException {

   167         if (encode) {

   168             if ((count += 3) > bytesPerLine) {

   169                 out.write('=');

   170                 out.write('\r');

   171                 out.write('\n');

   172                 count = 3; // set the next line's length

   173             }

   174             out.write('=');

   175             out.write(hex[c >> 4]);

   176             out.write(hex[c & 0xf]);

   177         } else {

   178             if (++count > bytesPerLine) {

   179                 out.write('=');

   180                 out.write('\r');

   181                 out.write('\n');

   182                 count = 1; // set the next line's length

   183             }

   184             out.write(c);

   185         }

   186     }

   187 

   188     /**** begin TEST program ***

   189     public static void main(String argv[]) throws Exception {

   190         FileInputStream infile = new FileInputStream(argv[0]);

   191         QPEncoderStream encoder = new QPEncoderStream(System.out);

   192         int c;

   193 

   194         while ((c = infile.read()) != -1)

   195             encoder.write(c);

   196         encoder.close();

   197     }

   198     *** end TEST program ***/

   199 }