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.stream; |
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21 | |
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22 | import java.io.IOException; |
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23 | |
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24 | import org.apache.james.mime4j.MimeException; |
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25 | import org.apache.james.mime4j.codec.DecodeMonitor; |
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26 | import org.apache.james.mime4j.io.LineReaderInputStream; |
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27 | import org.apache.james.mime4j.io.MaxHeaderLengthLimitException; |
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28 | import org.apache.james.mime4j.io.MaxHeaderLimitException; |
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29 | import org.apache.james.mime4j.io.MaxLineLimitException; |
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30 | import org.apache.james.mime4j.util.ByteArrayBuffer; |
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31 | import org.apache.james.mime4j.util.CharsetUtil; |
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32 | |
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33 | /** |
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34 | * Abstract MIME entity. |
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35 | */ |
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36 | public abstract class AbstractEntity implements EntityStateMachine { |
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37 | |
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38 | protected final EntityState startState; |
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39 | protected final EntityState endState; |
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40 | protected final MimeEntityConfig config; |
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41 | protected final MutableBodyDescriptor body; |
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42 | |
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43 | protected EntityState state; |
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44 | |
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45 | private final ByteArrayBuffer linebuf; |
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46 | |
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47 | private int lineCount; |
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48 | private RawField field; |
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49 | private boolean endOfHeader; |
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50 | private int headerCount; |
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51 | protected final DecodeMonitor monitor; |
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52 | |
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53 | AbstractEntity( |
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54 | MutableBodyDescriptor body, |
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55 | EntityState startState, |
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56 | EntityState endState, |
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57 | MimeEntityConfig config, |
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58 | DecodeMonitor monitor) { |
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59 | this.state = startState; |
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60 | this.startState = startState; |
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61 | this.endState = endState; |
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62 | this.config = config; |
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63 | this.body = body; |
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64 | this.linebuf = new ByteArrayBuffer(64); |
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65 | this.lineCount = 0; |
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66 | this.endOfHeader = false; |
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67 | this.headerCount = 0; |
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68 | this.monitor = monitor; |
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69 | } |
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70 | |
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71 | public EntityState getState() { |
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72 | return state; |
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73 | } |
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74 | |
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75 | /** |
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76 | * Returns the current line number or <code>-1</code> if line number |
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77 | * information is not available. |
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78 | */ |
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79 | protected abstract int getLineNumber(); |
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80 | |
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81 | protected abstract LineReaderInputStream getDataStream(); |
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82 | |
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83 | private ByteArrayBuffer fillFieldBuffer() throws IOException, MimeException { |
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84 | if (endOfHeader) |
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85 | throw new IllegalStateException(); |
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86 | |
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87 | int maxHeaderLen = config.getMaxHeaderLen(); |
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88 | LineReaderInputStream instream = getDataStream(); |
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89 | ByteArrayBuffer fieldbuf = new ByteArrayBuffer(64); |
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90 | |
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91 | try { |
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92 | for (;;) { |
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93 | // If there's still data stuck in the line buffer |
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94 | // copy it to the field buffer |
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95 | int len = linebuf.length(); |
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96 | if (maxHeaderLen > 0 && fieldbuf.length() + len >= maxHeaderLen) { |
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97 | throw new MaxHeaderLengthLimitException("Maximum header length limit exceeded"); |
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98 | } |
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99 | if (len > 0) { |
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100 | fieldbuf.append(linebuf.buffer(), 0, len); |
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101 | } |
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102 | linebuf.clear(); |
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103 | if (instream.readLine(linebuf) == -1) { |
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104 | monitor(Event.HEADERS_PREMATURE_END); |
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105 | endOfHeader = true; |
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106 | break; |
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107 | } |
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108 | len = linebuf.length(); |
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109 | if (len > 0 && linebuf.byteAt(len - 1) == '\n') { |
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110 | len--; |
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111 | } |
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112 | if (len > 0 && linebuf.byteAt(len - 1) == '\r') { |
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113 | len--; |
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114 | } |
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115 | if (len == 0) { |
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116 | // empty line detected |
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117 | endOfHeader = true; |
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118 | break; |
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119 | } |
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120 | lineCount++; |
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121 | if (lineCount > 1) { |
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122 | int ch = linebuf.byteAt(0); |
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123 | if (ch != CharsetUtil.SP && ch != CharsetUtil.HT) { |
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124 | // new header detected |
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125 | break; |
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126 | } |
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127 | } |
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128 | } |
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129 | } catch (MaxLineLimitException e) { |
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130 | throw new MimeException(e); |
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131 | } |
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132 | |
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133 | return fieldbuf; |
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134 | } |
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135 | |
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136 | protected boolean parseField() throws MimeException, IOException { |
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137 | int maxHeaderCount = config.getMaxHeaderCount(); |
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138 | // the loop is here to transparently skip invalid headers |
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139 | for (;;) { |
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140 | if (endOfHeader) { |
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141 | return false; |
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142 | } |
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143 | if (maxHeaderCount > 0 && headerCount >= maxHeaderCount) { |
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144 | throw new MaxHeaderLimitException("Maximum header limit exceeded"); |
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145 | } |
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146 | |
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147 | ByteArrayBuffer fieldbuf = fillFieldBuffer(); |
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148 | headerCount++; |
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149 | |
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150 | // Strip away line delimiter |
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151 | int origLen = fieldbuf.length(); |
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152 | int len = fieldbuf.length(); |
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153 | if (len > 0 && fieldbuf.byteAt(len - 1) == '\n') { |
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154 | len--; |
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155 | } |
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156 | if (len > 0 && fieldbuf.byteAt(len - 1) == '\r') { |
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157 | len--; |
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158 | } |
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159 | fieldbuf.setLength(len); |
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160 | |
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161 | try { |
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162 | field = new RawField(fieldbuf); |
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163 | if (field.isObsoleteSyntax()) { |
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164 | monitor(Event.OBSOLETE_HEADER); |
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165 | } |
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166 | body.addField(field); |
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167 | return true; |
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168 | } catch (MimeException e) { |
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169 | monitor(Event.INVALID_HEADER); |
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170 | if (config.isMalformedHeaderStartsBody()) { |
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171 | fieldbuf.setLength(origLen); |
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172 | LineReaderInputStream instream = getDataStream(); |
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173 | if (!instream.unread(fieldbuf)) throw new MimeParseEventException(Event.INVALID_HEADER); |
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174 | return false; |
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175 | } |
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176 | } |
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177 | } |
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178 | } |
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179 | |
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180 | /** |
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181 | * <p>Gets a descriptor for the current entity. |
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182 | * This method is valid if {@link #getState()} returns:</p> |
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183 | * <ul> |
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184 | * <li>{@link EntityState#T_BODY}</li> |
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185 | * <li>{@link EntityState#T_START_MULTIPART}</li> |
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186 | * <li>{@link EntityState#T_EPILOGUE}</li> |
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187 | * <li>{@link EntityState#T_PREAMBLE}</li> |
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188 | * </ul> |
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189 | * @return <code>BodyDescriptor</code>, not nulls |
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190 | */ |
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191 | public BodyDescriptor getBodyDescriptor() { |
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192 | switch (getState()) { |
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193 | case T_BODY: |
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194 | case T_START_MULTIPART: |
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195 | case T_PREAMBLE: |
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196 | case T_EPILOGUE: |
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197 | case T_END_OF_STREAM: |
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198 | return body; |
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199 | default: |
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200 | throw new IllegalStateException("Invalid state :" + stateToString(state)); |
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201 | } |
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202 | } |
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203 | |
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204 | /** |
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205 | * This method is valid, if {@link #getState()} returns {@link EntityState#T_FIELD}. |
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206 | * @return String with the fields raw contents. |
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207 | * @throws IllegalStateException {@link #getState()} returns another |
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208 | * value than {@link EntityState#T_FIELD}. |
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209 | */ |
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210 | public RawField getField() { |
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211 | switch (getState()) { |
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212 | case T_FIELD: |
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213 | return field; |
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214 | default: |
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215 | throw new IllegalStateException("Invalid state :" + stateToString(state)); |
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216 | } |
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217 | } |
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218 | |
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219 | /** |
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220 | * Monitors the given event. |
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221 | * Subclasses may override to perform actions upon events. |
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222 | * Base implementation logs at warn. |
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223 | * @param event <code>Event</code>, not null |
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224 | * @throws MimeException subclasses may elect to throw this exception upon |
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225 | * invalid content |
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226 | * @throws IOException subclasses may elect to throw this exception |
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227 | */ |
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228 | protected void monitor(Event event) throws MimeException, IOException { |
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229 | if (monitor.isListening()) { |
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230 | String message = message(event); |
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231 | if (monitor.warn(message, "ignoring")) { |
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232 | throw new MimeParseEventException(event); |
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233 | } |
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234 | } |
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235 | } |
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236 | |
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237 | /** |
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238 | * Creates an indicative message suitable for display |
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239 | * based on the given event and the current state of the system. |
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240 | * @param event <code>Event</code>, not null |
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241 | * @return message suitable for use as a message in an exception |
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242 | * or for logging |
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243 | */ |
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244 | protected String message(Event event) { |
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245 | final String message; |
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246 | if (event == null) { |
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247 | message = "Event is unexpectedly null."; |
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248 | } else { |
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249 | message = event.toString(); |
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250 | } |
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251 | |
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252 | int lineNumber = getLineNumber(); |
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253 | if (lineNumber <= 0) |
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254 | return message; |
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255 | else |
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256 | return "Line " + lineNumber + ": " + message; |
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257 | } |
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258 | |
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259 | @Override |
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260 | public String toString() { |
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261 | return getClass().getName() + " [" + stateToString(state) |
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262 | + "][" + body.getMimeType() + "][" + body.getBoundary() + "]"; |
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263 | } |
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264 | |
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265 | /** |
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266 | * Renders a state as a string suitable for logging. |
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267 | * @param state |
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268 | * @return rendered as string, not null |
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269 | */ |
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270 | public static final String stateToString(EntityState state) { |
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271 | final String result; |
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272 | switch (state) { |
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273 | case T_END_OF_STREAM: |
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274 | result = "End of stream"; |
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275 | break; |
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276 | case T_START_MESSAGE: |
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277 | result = "Start message"; |
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278 | break; |
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279 | case T_END_MESSAGE: |
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280 | result = "End message"; |
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281 | break; |
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282 | case T_RAW_ENTITY: |
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283 | result = "Raw entity"; |
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284 | break; |
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285 | case T_START_HEADER: |
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286 | result = "Start header"; |
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287 | break; |
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288 | case T_FIELD: |
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289 | result = "Field"; |
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290 | break; |
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291 | case T_END_HEADER: |
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292 | result = "End header"; |
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293 | break; |
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294 | case T_START_MULTIPART: |
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295 | result = "Start multipart"; |
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296 | break; |
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297 | case T_END_MULTIPART: |
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298 | result = "End multipart"; |
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299 | break; |
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300 | case T_PREAMBLE: |
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301 | result = "Preamble"; |
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302 | break; |
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303 | case T_EPILOGUE: |
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304 | result = "Epilogue"; |
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305 | break; |
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306 | case T_START_BODYPART: |
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307 | result = "Start bodypart"; |
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308 | break; |
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309 | case T_END_BODYPART: |
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310 | result = "End bodypart"; |
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311 | break; |
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312 | case T_BODY: |
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313 | result = "Body"; |
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314 | break; |
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315 | default: |
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316 | result = "Unknown"; |
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317 | break; |
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318 | } |
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319 | return result; |
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320 | } |
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321 | |
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322 | } |
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