ext/javax.mail.mbox/src/com/sun/mail/mbox/NewlineOutputStream.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 import java.nio.charset.StandardCharsets;
  21
  22 /**
  23  * Convert the various newline conventions to the local platform's
  24  * newline convention.  Optionally, make sure the output ends with
  25  * a blank line.
  26  */
  27 public class NewlineOutputStream extends FilterOutputStream {
  28     private int lastb = -1;
  29     private int bol = 1; // number of times in a row we're at beginning of line
  30     private final boolean endWithBlankLine;
  31     private static final byte[] newline;
  32
  33     static {
  34         String s = null;
  35         try {
  36             s = System.lineSeparator();
  37         } catch (SecurityException sex) {
  38             // ignore, should never happen
  39         }
  40         if (s == null || s.length() <= 0)
  41             s = "\n";
  42         newline = s.getBytes(StandardCharsets.ISO_8859_1);
  43     }
  44
  45     public NewlineOutputStream(OutputStream os) {
  46         this(os, false);
  47     }
  48
  49     public NewlineOutputStream(OutputStream os, boolean endWithBlankLine) {
  50         super(os);
  51         this.endWithBlankLine = endWithBlankLine;
  52     }
  53
  54     public void write(int b) throws IOException {
  55         if (b == '\r') {
  56             out.write(newline);
  57             bol++;
  58         } else if (b == '\n') {
  59             if (lastb != '\r') {
  60                 out.write(newline);
  61                 bol++;
  62             }
  63         } else {
  64             out.write(b);
  65             bol = 0;    // no longer at beginning of line
  66         }
  67         lastb = b;
  68     }
  69
  70     public void write(byte b[]) throws IOException {
  71         write(b, 0, b.length);
  72     }
  73
  74     public void write(byte b[], int off, int len) throws IOException {
  75         for (int i = 0 ; i < len ; i++) {
  76             write(b[off + i]);
  77         }
  78     }
  79
  80     public void flush() throws IOException {
  81         if (endWithBlankLine) {
  82             if (bol == 0) {
  83                 // not at bol, return to bol and add a blank line
  84                 out.write(newline);
  85                 out.write(newline);
  86             } else if (bol == 1) {
  87                 // at bol, add a blank line
  88                 out.write(newline);
  89             }
  90         }
  91         bol = 2;
  92         out.flush();
  93     }
  94 }