ext/javax.mail.mbox/src/com/sun/mail/mbox/ContentLengthUpdater.java

   1 /*
   2  * Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v. 2.0, which is available at
   6  * http://www.eclipse.org/legal/epl-2.0.
   7  *
   8  * This Source Code may also be made available under the following Secondary
   9  * Licenses when the conditions for such availability set forth in the
  10  * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
  11  * version 2 with the GNU Classpath Exception, which is available at
  12  * https://www.gnu.org/software/classpath/license.html.
  13  *
  14  * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
  15  */
  16
  17 package com.sun.mail.mbox;
  18
  19 import java.io.*;
  20
  21 /**
  22  * Update the Content-Length header in the message written to the stream.
  23  */
  24 class ContentLengthUpdater extends FilterOutputStream {
  25     private String contentLength;
  26     private boolean inHeader = true;
  27     private boolean sawContentLength = false;
  28     private int lastb1 = -1, lastb2 = -1;
  29     private StringBuilder line = new StringBuilder();
  30
  31     public ContentLengthUpdater(OutputStream os, long contentLength) {
  32         super(os);
  33         this.contentLength = "Content-Length: " + contentLength;
  34     }
  35
  36     public void write(int b) throws IOException {
  37         if (inHeader) {
  38             String eol = "\n";
  39             // First, determine if we're still in the header.
  40             if (b == '\r') {
  41                 // if line terminator is CR
  42                 if (lastb1 == '\r') {
  43                     inHeader = false;
  44                     eol = "\r";
  45                 // else, if line terminator is CRLF
  46                 } else if (lastb1 == '\n' && lastb2 == '\r') {
  47                     inHeader = false;
  48                     eol = "\r\n";
  49                 }
  50             // else, if line terminator is \n
  51             } else if (b == '\n') {
  52                 if (lastb1 == '\n') {
  53                     inHeader = false;
  54                     eol = "\n";
  55                 }
  56             }
  57
  58             // If we're no longer in the header, and we haven't seen
  59             // a Content-Length header yet, it's time to put one out.
  60             if (!inHeader && !sawContentLength) {
  61                 out.write(contentLength.getBytes("iso-8859-1"));
  62                 out.write(eol.getBytes("iso-8859-1"));
  63             }
  64
  65             // If we have a full line, see if it's a Content-Length header.
  66             if (b == '\r' || (b == '\n' && lastb1 != '\r')) {
  67                 if (line.toString().regionMatches(true, 0,
  68                                         "content-length:", 0, 15)) {
  69                     // yup, got it
  70                     sawContentLength = true;
  71                     // put out the new version
  72                     out.write(contentLength.getBytes("iso-8859-1"));
  73                 } else {
  74                     // not a Content-Length header, just write it out
  75                     out.write(line.toString().getBytes("iso-8859-1"));
  76                 }
  77                 line.setLength(0);      // clear buffer for next line
  78             }
  79             if (b == '\r' || b == '\n')
  80                 out.write(b);   // write out line terminator immediately
  81             else
  82                 line.append((char)b);   // accumulate characters of the line
  83
  84             // rotate saved characters for next time through loop
  85             lastb2 = lastb1;
  86             lastb1 = b;
  87         } else
  88             out.write(b);               // not in the header, just write it out
  89     }
  90
  91     public void write(byte[] b) throws IOException {
  92         if (inHeader)
  93             write(b, 0, b.length);
  94         else
  95             out.write(b);
  96     }
  97
  98     public void write(byte[] b, int off, int len) throws IOException {
  99         if (inHeader) {
 100             for (int i = 0 ; i < len ; i++) {
 101                 write(b[off + i]);
 102             }
 103         } else
 104             out.write(b, off, len);
 105     }
 106
 107     // for testing
 108     public static void main(String argv[]) throws Exception {
 109         int b;
 110         ContentLengthUpdater os =
 111             new ContentLengthUpdater(System.out, Long.parseLong(argv[0]));
 112         while ((b = System.in.read()) >= 0)
 113             os.write(b);
 114         os.flush();
 115     }
 116 }