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.codec; |
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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 | |
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25 | import org.apache.james.mime4j.util.ByteArrayBuffer; |
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26 | |
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27 | /** |
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28 | * Performs Quoted-Printable decoding on an underlying stream. |
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29 | */ |
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30 | public class QuotedPrintableInputStream extends InputStream { |
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31 | |
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32 | private static final int DEFAULT_BUFFER_SIZE = 1024 * 2; |
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33 | |
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34 | private static final byte EQ = 0x3D; |
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35 | private static final byte CR = 0x0D; |
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36 | private static final byte LF = 0x0A; |
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37 | |
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38 | private final byte[] singleByte = new byte[1]; |
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39 | |
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40 | private final InputStream in; |
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41 | private final ByteArrayBuffer decodedBuf; |
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42 | private final ByteArrayBuffer blanks; |
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43 | |
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44 | private final byte[] encoded; |
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45 | private int pos = 0; // current index into encoded buffer |
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46 | private int limit = 0; // current size of encoded buffer |
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47 | |
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48 | private boolean closed; |
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49 | |
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50 | private final DecodeMonitor monitor; |
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51 | |
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52 | public QuotedPrintableInputStream(final InputStream in, DecodeMonitor monitor) { |
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53 | this(DEFAULT_BUFFER_SIZE, in, monitor); |
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54 | } |
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55 | |
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56 | protected QuotedPrintableInputStream(final int bufsize, final InputStream in, DecodeMonitor monitor) { |
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57 | super(); |
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58 | this.in = in; |
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59 | this.encoded = new byte[bufsize]; |
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60 | this.decodedBuf = new ByteArrayBuffer(512); |
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61 | this.blanks = new ByteArrayBuffer(512); |
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62 | this.closed = false; |
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63 | this.monitor = monitor; |
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64 | } |
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65 | |
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66 | protected QuotedPrintableInputStream(final int bufsize, final InputStream in, boolean strict) { |
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67 | this(bufsize, in, strict ? DecodeMonitor.STRICT : DecodeMonitor.SILENT); |
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68 | } |
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69 | |
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70 | public QuotedPrintableInputStream(final InputStream in, boolean strict) { |
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71 | this(DEFAULT_BUFFER_SIZE, in, strict); |
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72 | } |
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73 | |
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74 | public QuotedPrintableInputStream(final InputStream in) { |
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75 | this(in, false); |
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76 | } |
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77 | |
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78 | /** |
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79 | * Terminates Quoted-Printable coded content. This method does NOT close |
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80 | * the underlying input stream. |
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81 | * |
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82 | * @throws IOException on I/O errors. |
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83 | */ |
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84 | @Override |
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85 | public void close() throws IOException { |
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86 | closed = true; |
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87 | } |
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88 | |
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89 | private int fillBuffer() throws IOException { |
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90 | // Compact buffer if needed |
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91 | if (pos < limit) { |
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92 | System.arraycopy(encoded, pos, encoded, 0, limit - pos); |
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93 | limit -= pos; |
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94 | pos = 0; |
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95 | } else { |
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96 | limit = 0; |
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97 | pos = 0; |
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98 | } |
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99 | |
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100 | int capacity = encoded.length - limit; |
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101 | if (capacity > 0) { |
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102 | int bytesRead = in.read(encoded, limit, capacity); |
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103 | if (bytesRead > 0) { |
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104 | limit += bytesRead; |
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105 | } |
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106 | return bytesRead; |
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107 | } else { |
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108 | return 0; |
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109 | } |
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110 | } |
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111 | |
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112 | private int getnext() { |
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113 | if (pos < limit) { |
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114 | byte b = encoded[pos]; |
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115 | pos++; |
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116 | return b & 0xFF; |
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117 | } else { |
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118 | return -1; |
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119 | } |
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120 | } |
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121 | |
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122 | private int peek(int i) { |
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123 | if (pos + i < limit) { |
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124 | return encoded[pos + i] & 0xFF; |
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125 | } else { |
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126 | return -1; |
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127 | } |
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128 | } |
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129 | |
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130 | private int transfer( |
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131 | final int b, final byte[] buffer, final int from, final int to, boolean keepblanks) throws IOException { |
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132 | int index = from; |
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133 | if (keepblanks && blanks.length() > 0) { |
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134 | int chunk = Math.min(blanks.length(), to - index); |
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135 | System.arraycopy(blanks.buffer(), 0, buffer, index, chunk); |
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136 | index += chunk; |
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137 | int remaining = blanks.length() - chunk; |
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138 | if (remaining > 0) { |
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139 | decodedBuf.append(blanks.buffer(), chunk, remaining); |
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140 | } |
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141 | blanks.clear(); |
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142 | } else if (blanks.length() > 0 && !keepblanks) { |
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143 | StringBuilder sb = new StringBuilder(blanks.length() * 3); |
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144 | for (int i = 0; i < blanks.length(); i++) sb.append(" "+blanks.byteAt(i)); |
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145 | if (monitor.warn("ignored blanks", sb.toString())) |
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146 | throw new IOException("ignored blanks"); |
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147 | } |
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148 | if (b != -1) { |
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149 | if (index < to) { |
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150 | buffer[index++] = (byte) b; |
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151 | } else { |
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152 | decodedBuf.append(b); |
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153 | } |
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154 | } |
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155 | return index; |
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156 | } |
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157 | |
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158 | private int read0(final byte[] buffer, final int off, final int len) throws IOException { |
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159 | boolean eof = false; |
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160 | int from = off; |
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161 | int to = off + len; |
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162 | int index = off; |
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163 | |
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164 | // check if a previous invocation left decoded content |
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165 | if (decodedBuf.length() > 0) { |
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166 | int chunk = Math.min(decodedBuf.length(), to - index); |
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167 | System.arraycopy(decodedBuf.buffer(), 0, buffer, index, chunk); |
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168 | decodedBuf.remove(0, chunk); |
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169 | index += chunk; |
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170 | } |
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171 | |
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172 | while (index < to) { |
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173 | |
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174 | if (limit - pos < 3) { |
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175 | int bytesRead = fillBuffer(); |
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176 | eof = bytesRead == -1; |
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177 | } |
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178 | |
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179 | // end of stream? |
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180 | if (limit - pos == 0 && eof) { |
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181 | return index == from ? -1 : index - from; |
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182 | } |
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183 | |
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184 | boolean lastWasCR = false; |
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185 | while (pos < limit && index < to) { |
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186 | int b = encoded[pos++] & 0xFF; |
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187 | |
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188 | if (lastWasCR && b != LF) { |
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189 | if (monitor.warn("Found CR without LF", "Leaving it as is")) |
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190 | throw new IOException("Found CR without LF"); |
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191 | index = transfer(CR, buffer, index, to, false); |
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192 | } else if (!lastWasCR && b == LF) { |
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193 | if (monitor.warn("Found LF without CR", "Translating to CRLF")) |
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194 | throw new IOException("Found LF without CR"); |
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195 | } |
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196 | |
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197 | if (b == CR) { |
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198 | lastWasCR = true; |
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199 | continue; |
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200 | } else { |
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201 | lastWasCR = false; |
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202 | } |
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203 | |
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204 | if (b == LF) { |
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205 | // at end of line |
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206 | if (blanks.length() == 0) { |
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207 | index = transfer(CR, buffer, index, to, false); |
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208 | index = transfer(LF, buffer, index, to, false); |
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209 | } else { |
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210 | if (blanks.byteAt(0) != EQ) { |
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211 | // hard line break |
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212 | index = transfer(CR, buffer, index, to, false); |
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213 | index = transfer(LF, buffer, index, to, false); |
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214 | } |
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215 | } |
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216 | blanks.clear(); |
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217 | } else if (b == EQ) { |
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218 | if (limit - pos < 2 && !eof) { |
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219 | // not enough buffered data |
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220 | pos--; |
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221 | break; |
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222 | } |
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223 | |
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224 | // found special char '=' |
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225 | int b2 = getnext(); |
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226 | if (b2 == EQ) { |
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227 | index = transfer(b2, buffer, index, to, true); |
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228 | // deal with '==\r\n' brokenness |
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229 | int bb1 = peek(0); |
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230 | int bb2 = peek(1); |
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231 | if (bb1 == LF || (bb1 == CR && bb2 == LF)) { |
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232 | monitor.warn("Unexpected ==EOL encountered", "== 0x"+bb1+" 0x"+bb2); |
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233 | blanks.append(b2); |
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234 | } else { |
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235 | monitor.warn("Unexpected == encountered", "=="); |
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236 | } |
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237 | } else if (Character.isWhitespace((char) b2)) { |
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238 | // soft line break |
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239 | index = transfer(-1, buffer, index, to, true); |
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240 | if (b2 != LF) { |
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241 | blanks.append(b); |
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242 | blanks.append(b2); |
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243 | } |
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244 | } else { |
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245 | int b3 = getnext(); |
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246 | int upper = convert(b2); |
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247 | int lower = convert(b3); |
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248 | if (upper < 0 || lower < 0) { |
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249 | monitor.warn("Malformed encoded value encountered", "leaving "+((char) EQ)+((char) b2)+((char) b3)+" as is"); |
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250 | // TODO see MIME4J-160 |
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251 | index = transfer(EQ, buffer, index, to, true); |
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252 | index = transfer(b2, buffer, index, to, false); |
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253 | index = transfer(b3, buffer, index, to, false); |
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254 | } else { |
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255 | index = transfer((upper << 4) | lower, buffer, index, to, true); |
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256 | } |
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257 | } |
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258 | } else if (Character.isWhitespace(b)) { |
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259 | blanks.append(b); |
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260 | } else { |
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261 | index = transfer((int) b & 0xFF, buffer, index, to, true); |
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262 | } |
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263 | } |
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264 | } |
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265 | return to - from; |
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266 | } |
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267 | |
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268 | /** |
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269 | * Converts '0' => 0, 'A' => 10, etc. |
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270 | * @param c ASCII character value. |
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271 | * @return Numeric value of hexadecimal character. |
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272 | */ |
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273 | private int convert(int c) { |
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274 | if (c >= '0' && c <= '9') { |
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275 | return (c - '0'); |
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276 | } else if (c >= 'A' && c <= 'F') { |
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277 | return (0xA + (c - 'A')); |
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278 | } else if (c >= 'a' && c <= 'f') { |
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279 | return (0xA + (c - 'a')); |
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280 | } else { |
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281 | return -1; |
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282 | } |
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283 | } |
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284 | |
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285 | @Override |
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286 | public int read() throws IOException { |
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287 | if (closed) { |
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288 | throw new IOException("Stream has been closed"); |
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289 | } |
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290 | for (;;) { |
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291 | int bytes = read(singleByte, 0, 1); |
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292 | if (bytes == -1) { |
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293 | return -1; |
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294 | } |
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295 | if (bytes == 1) { |
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296 | return singleByte[0] & 0xff; |
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297 | } |
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298 | } |
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299 | } |
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300 | |
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301 | @Override |
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302 | public int read(byte[] b, int off, int len) throws IOException { |
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303 | if (closed) { |
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304 | throw new IOException("Stream has been closed"); |
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305 | } |
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306 | return read0(b, off, len); |
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307 | } |
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308 | |
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309 | } |
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