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Java > Open Source Codes > org > columba > ristretto > smtp > StopWordSafeInputStream


1 /* ***** BEGIN LICENSE BLOCK *****
2  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
3  *
4  * The contents of this file are subject to the Mozilla Public License Version
5  * 1.1 (the "License"); you may not use this file except in compliance with
6  * the License. You may obtain a copy of the License at
7  * http://www.mozilla.org/MPL/
8  *
9  * Software distributed under the License is distributed on an "AS IS" basis,
10  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
11  * for the specific language governing rights and limitations under the
12  * License.
13  *
14  * The Original Code is Ristretto Mail API.
15  *
16  * The Initial Developers of the Original Code are
17  * Timo Stich and Frederik Dietz.
18  * Portions created by the Initial Developers are Copyright (C) 2004
19  * All Rights Reserved.
20  *
21  * Contributor(s):
22  *
23  * Alternatively, the contents of this file may be used under the terms of
24  * either the GNU General Public License Version 2 or later (the "GPL"), or
25  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
26  * in which case the provisions of the GPL or the LGPL are applicable instead
27  * of those above. If you wish to allow use of your version of this file only
28  * under the terms of either the GPL or the LGPL, and not to allow others to
29  * use your version of this file under the terms of the MPL, indicate your
30  * decision by deleting the provisions above and replace them with the notice
31  * and other provisions required by the GPL or the LGPL. If you do not delete
32  * the provisions above, a recipient may use your version of this file under
33  * the terms of any one of the MPL, the GPL or the LGPL.
34  *
35  * ***** END LICENSE BLOCK ***** */
36 package org.columba.ristretto.smtp;
37
38 import java.io.FilterInputStream JavaDoc;
39 import java.io.IOException JavaDoc;
40 import java.io.InputStream JavaDoc;
41
42
43 /**
44  * FilterInputStream that safely wraps stop words.
45  * A stop word is CR LF '.' CR LF. If a message is sent
46  * that contains stop words they must be encoded so that
47  * the server continues receiving. This is done by adding
48  * a '.'. (See RFC2821)
49  *
50  * @author Timo Stich <tstich@users.sourceforge.net>
51  */
52 public class StopWordSafeInputStream extends FilterInputStream JavaDoc {
53
54     private static final int CLRF = 0;
55     private static final int NORMAL = 1;
56     private static final int BUFFER = 2;
57     
58     
59     private int buffer;
60     private int mode;
61     
62     /**
63      * Constructs a StopWordSafeInputStream.
64      *
65      * @param arg0
66      */
67     public StopWordSafeInputStream(InputStream JavaDoc arg0) {
68         super(arg0);
69         mode = CLRF;
70     }
71
72     /**
73      * @see java.io.InputStream#read()
74      */
75     public int read() throws IOException JavaDoc {
76         if( mode == BUFFER ) {
77             mode = NORMAL;
78             return buffer;
79         }
80         
81         buffer = in.read();
82
83         if( mode == CLRF && buffer == '.') {
84             mode = BUFFER;
85             
86             // insert a . before
87 return '.';
88         }
89         
90         if( buffer == '\n') {
91             mode = CLRF;
92         } else {
93             mode = NORMAL;
94         }
95         
96         return buffer;
97     }
98
99     /**
100      * @see java.io.InputStream#read(byte[], int, int)
101      */
102     public int read(byte[] arg0, int arg1, int arg2) throws IOException JavaDoc {
103         int next;
104         for( int i=0; i<arg2; i++) {
105             next = read();
106             if( next == -1 ) {
107                 if( i == 0 ) {
108                     return -1;
109                 } else {
110                     return i;
111                 }
112             }
113             arg0[arg1+i] = (byte) next;
114         }
115         return arg2;
116     }
117
118 }
119
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