[6785] | 1 | /**************************************************************** |
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| 2 | * Licensed to the Apache Software Foundation (ASF) under one * |
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| 3 | * or more contributor license agreements. See the NOTICE file * |
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| 4 | * distributed with this work for additional information * |
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| 5 | * regarding copyright ownership. The ASF licenses this file * |
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| 6 | * to you under the Apache License, Version 2.0 (the * |
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| 7 | * "License"); you may not use this file except in compliance * |
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| 8 | * with the License. You may obtain a copy of the License at * |
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| 9 | * * |
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| 10 | * http://www.apache.org/licenses/LICENSE-2.0 * |
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| 11 | * * |
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| 12 | * Unless required by applicable law or agreed to in writing, * |
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| 13 | * software distributed under the License is distributed on an * |
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| 14 | * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * |
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| 15 | * KIND, either express or implied. See the License for the * |
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| 16 | * specific language governing permissions and limitations * |
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| 17 | * under the License. * |
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| 18 | ****************************************************************/ |
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| 19 | |
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| 20 | package org.apache.james.mime4j.io; |
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| 21 | |
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| 22 | import java.io.IOException; |
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| 23 | import java.io.InputStream; |
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| 24 | import java.io.PushbackInputStream; |
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| 25 | |
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| 26 | /** |
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| 27 | * InputStream which converts <code>\r</code> |
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| 28 | * bytes not followed by <code>\n</code> and <code>\n</code> not |
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| 29 | * preceded by <code>\r</code> to <code>\r\n</code>. |
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| 30 | */ |
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| 31 | public class EOLConvertingInputStream extends InputStream { |
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| 32 | /** Converts single '\r' to '\r\n' */ |
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| 33 | public static final int CONVERT_CR = 1; |
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| 34 | /** Converts single '\n' to '\r\n' */ |
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| 35 | public static final int CONVERT_LF = 2; |
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| 36 | /** Converts single '\r' and '\n' to '\r\n' */ |
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| 37 | public static final int CONVERT_BOTH = 3; |
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| 38 | |
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| 39 | private PushbackInputStream in = null; |
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| 40 | private int previous = 0; |
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| 41 | private int flags = CONVERT_BOTH; |
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| 42 | |
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| 43 | /** |
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| 44 | * Creates a new <code>EOLConvertingInputStream</code> |
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| 45 | * instance converting bytes in the given <code>InputStream</code>. |
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| 46 | * The flag <code>CONVERT_BOTH</code> is the default. |
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| 47 | * |
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| 48 | * @param in the <code>InputStream</code> to read from. |
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| 49 | */ |
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| 50 | public EOLConvertingInputStream(InputStream in) { |
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| 51 | this(in, CONVERT_BOTH); |
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| 52 | } |
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| 53 | /** |
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| 54 | * Creates a new <code>EOLConvertingInputStream</code> |
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| 55 | * instance converting bytes in the given <code>InputStream</code>. |
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| 56 | * |
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| 57 | * @param in the <code>InputStream</code> to read from. |
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| 58 | * @param flags one of <code>CONVERT_CR</code>, <code>CONVERT_LF</code> or |
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| 59 | * <code>CONVERT_BOTH</code>. |
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| 60 | */ |
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| 61 | public EOLConvertingInputStream(InputStream in, int flags) { |
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| 62 | super(); |
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| 63 | |
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| 64 | this.in = new PushbackInputStream(in, 2); |
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| 65 | this.flags = flags; |
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| 66 | } |
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| 67 | |
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| 68 | /** |
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| 69 | * Closes the underlying stream. |
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| 70 | * |
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| 71 | * @throws IOException on I/O errors. |
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| 72 | */ |
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| 73 | @Override |
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| 74 | public void close() throws IOException { |
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| 75 | in.close(); |
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| 76 | } |
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| 77 | |
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| 78 | /** |
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| 79 | * @see java.io.InputStream#read() |
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| 80 | */ |
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| 81 | @Override |
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| 82 | public int read() throws IOException { |
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| 83 | int b = in.read(); |
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| 84 | |
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| 85 | if (b == -1) { |
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| 86 | return -1; |
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| 87 | } |
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| 88 | |
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| 89 | if ((flags & CONVERT_CR) != 0 && b == '\r') { |
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| 90 | int c = in.read(); |
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| 91 | if (c != -1) { |
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| 92 | in.unread(c); |
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| 93 | } |
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| 94 | if (c != '\n') { |
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| 95 | in.unread('\n'); |
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| 96 | } |
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| 97 | } else if ((flags & CONVERT_LF) != 0 && b == '\n' && previous != '\r') { |
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| 98 | b = '\r'; |
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| 99 | in.unread('\n'); |
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| 100 | } |
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| 101 | |
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| 102 | previous = b; |
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| 103 | |
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| 104 | return b; |
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| 105 | } |
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| 106 | |
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| 107 | } |
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