1 | // Copyright 2012 Georg-August-Universität Göttingen, Germany |
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2 | // |
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3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
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4 | // you may not use this file except in compliance with the License. |
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5 | // You may obtain a copy of the License at |
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6 | // |
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7 | // http://www.apache.org/licenses/LICENSE-2.0 |
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8 | // |
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9 | // Unless required by applicable law or agreed to in writing, software |
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10 | // distributed under the License is distributed on an "AS IS" BASIS, |
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11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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12 | // See the License for the specific language governing permissions and |
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13 | // limitations under the License. |
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14 | |
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15 | package de.ugoe.cs.autoquest.httpmonitor; |
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16 | |
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17 | import java.io.File; |
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18 | import java.io.FileOutputStream; |
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19 | import java.io.IOException; |
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20 | import java.io.OutputStreamWriter; |
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21 | import java.io.PrintWriter; |
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22 | import java.text.DecimalFormat; |
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23 | import java.util.logging.Level; |
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24 | |
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25 | import javax.xml.bind.JAXBContext; |
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26 | import javax.xml.bind.JAXBException; |
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27 | import javax.xml.bind.Marshaller; |
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28 | |
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29 | import de.ugoe.cs.autoquest.plugin.http.logdata.HttpExchange; |
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30 | import de.ugoe.cs.autoquest.plugin.http.logdata.ObjectFactory; |
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31 | import de.ugoe.cs.util.console.Console; |
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32 | |
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33 | /** |
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34 | * <p> |
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35 | * dumps messages to a log file in the provided base log directory. The name of each finished log |
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36 | * file starts with the "httpmonitor_" followed by an index of the log file. An unfinished log file |
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37 | * has no index yet. A log file is finished if |
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38 | * <ul> |
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39 | * <li>the session is closed by a timeout</li> |
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40 | * <li>the HTTP monitor or proxy are normally shut down</li> |
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41 | * <li>on startup an unfinished log file is detected.</li> |
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42 | * <li>the {@link #MAXIMUM_LOG_FILE_SIZE} is reached</li> |
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43 | * </ul> |
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44 | * </p> |
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45 | * |
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46 | * @author Patrick Harms |
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47 | * @version 1.0 |
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48 | * |
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49 | */ |
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50 | public class HttpMonitorOutputWriter implements HttpMonitorComponent, HttpMonitorExchangeHandler { |
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51 | |
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52 | /** |
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53 | * the maximum size of an individual log file |
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54 | */ |
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55 | private static final int MAXIMUM_LOG_FILE_SIZE = 50000000; |
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56 | |
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57 | /** |
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58 | * the default log base directory if none is provided through the constructor |
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59 | */ |
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60 | private static final String DEFAULT_LOG_FILE_BASE_DIR = "logs"; |
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61 | |
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62 | /** |
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63 | * the currently used log file base directory |
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64 | */ |
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65 | private File logFileBaseDir; |
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66 | |
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67 | /** |
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68 | * the log file into which all messages are currently written |
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69 | */ |
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70 | private File logFile; |
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71 | |
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72 | /** |
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73 | * an output writer to be used for writing into the log file |
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74 | */ |
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75 | private PrintWriter outputWriter; |
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76 | |
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77 | /** |
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78 | * the time stamp of the last action taken on this writer (such as logging a message) |
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79 | */ |
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80 | private long lastUpdate; |
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81 | |
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82 | /** |
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83 | * <p> |
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84 | * initializes the writer with the log file base directory. |
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85 | * </p> |
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86 | * |
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87 | * @param logFileBaseDir the log file base directory, or null if the default directory shall |
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88 | * be taken |
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89 | */ |
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90 | public HttpMonitorOutputWriter(String logFileBaseDir) { |
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91 | if (logFileBaseDir == null) { |
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92 | this.logFileBaseDir = new File(DEFAULT_LOG_FILE_BASE_DIR); |
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93 | } |
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94 | else { |
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95 | this.logFileBaseDir = new File(logFileBaseDir); |
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96 | } |
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97 | |
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98 | lastUpdate = System.currentTimeMillis(); |
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99 | } |
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100 | |
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101 | /* (non-Javadoc) |
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102 | * @see de.ugoe.cs.autoquest.htmlmonitor.HttpMonitorComponent#init() |
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103 | */ |
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104 | @Override |
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105 | public synchronized void init() throws HttpMonitorException { |
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106 | if (outputWriter != null) { |
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107 | throw new IllegalStateException("already initialized. Call close() first"); |
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108 | } |
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109 | |
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110 | synchronized (HttpMonitorOutputWriter.class) { |
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111 | try { |
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112 | if (!logFileBaseDir.exists()) { |
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113 | if (!logFileBaseDir.mkdirs()) { |
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114 | throw new HttpMonitorException("log file directory " + logFileBaseDir + |
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115 | " can not be created"); |
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116 | } |
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117 | } |
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118 | else if (!logFileBaseDir.isDirectory()) { |
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119 | throw new HttpMonitorException("log file directory " + logFileBaseDir + |
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120 | " already exists as a file"); |
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121 | } |
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122 | |
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123 | logFile = new File(logFileBaseDir, getLogFileName(-1)); |
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124 | |
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125 | if (logFile.exists()) { |
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126 | rotateLogFile(); |
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127 | } |
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128 | |
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129 | createLogWriter(); |
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130 | } |
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131 | catch (IOException e) { |
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132 | throw new HttpMonitorException("could not open logfile " + logFile, e); |
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133 | } |
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134 | } |
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135 | |
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136 | lastUpdate = System.currentTimeMillis(); |
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137 | } |
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138 | |
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139 | /** |
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140 | * <p> |
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141 | * used to calculate a log file name. If the provided index is smaller 0, then no index |
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142 | * is added to the file name. A filename is e.g. "httpmonitor_001.log". |
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143 | * </p> |
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144 | * |
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145 | * @param index the index of the log file or -1 one, if no index shall be added |
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146 | * |
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147 | * @return the file name as described |
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148 | */ |
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149 | private String getLogFileName(int index) { |
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150 | String result = "httpmonitor"; |
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151 | |
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152 | if (index >= 0) { |
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153 | result += "_" + new DecimalFormat("000" ).format(index); |
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154 | } |
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155 | |
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156 | result += ".log"; |
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157 | |
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158 | return result; |
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159 | } |
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160 | |
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161 | /* (non-Javadoc) |
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162 | * @see de.ugoe.cs.autoquest.htmlmonitor.HttpMonitorComponent#start() |
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163 | */ |
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164 | @Override |
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165 | public synchronized void start() throws IllegalStateException, HttpMonitorException { |
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166 | lastUpdate = System.currentTimeMillis(); |
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167 | } |
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168 | |
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169 | /* (non-Javadoc) |
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170 | * @see HttpMonitorMessageListener#handleHttpMessage() |
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171 | */ |
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172 | @Override |
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173 | public synchronized void handleHttpExchange(HttpExchange httpExchange) { |
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174 | if (outputWriter == null) { |
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175 | throw new IllegalStateException("not initialized. Call init() first"); |
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176 | } |
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177 | |
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178 | try { |
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179 | JAXBContext jaxbContext = |
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180 | JAXBContext.newInstance(HttpExchange.class.getPackage().getName()); |
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181 | Marshaller marshaller = jaxbContext.createMarshaller(); |
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182 | |
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183 | marshaller.setProperty(Marshaller.JAXB_FRAGMENT, Boolean.TRUE); |
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184 | marshaller.marshal(new ObjectFactory().createHttpExchange(httpExchange), outputWriter); |
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185 | } |
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186 | catch (JAXBException e) { |
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187 | Console.traceln(Level.WARNING, "could not dump exchange to log file: " + e); |
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188 | Console.logException(e); |
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189 | } |
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190 | |
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191 | outputWriter.flush(); |
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192 | |
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193 | try { |
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194 | considerLogRotate(); |
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195 | } |
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196 | catch (IOException e) { |
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197 | throw new IllegalStateException("could not perform log rotation: " + e, e); |
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198 | } |
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199 | |
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200 | lastUpdate = System.currentTimeMillis(); |
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201 | } |
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202 | |
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203 | /** |
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204 | * <p> |
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205 | * checks, if the log file exceeded the {@link #MAXIMUM_LOG_FILE_SIZE}. If so, the current |
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206 | * log file is closed, the next log file name is determined and this new file is opened for |
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207 | * writing. |
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208 | * </p> |
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209 | */ |
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210 | private synchronized void considerLogRotate() throws IOException { |
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211 | if (logFile.length() > MAXIMUM_LOG_FILE_SIZE) { |
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212 | closeLogWriter(); |
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213 | rotateLogFile(); |
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214 | createLogWriter(); |
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215 | } |
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216 | } |
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217 | |
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218 | /** |
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219 | * <p> |
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220 | * renames the current log file to a new log file with the next available index. It further |
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221 | * sets the current log file to the default name, i.e. without index. |
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222 | * </p> |
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223 | */ |
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224 | private void rotateLogFile() { |
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225 | File clientLogDir = logFile.getParentFile(); |
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226 | File checkFile; |
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227 | |
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228 | int logFileIndex = -1; |
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229 | do { |
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230 | logFileIndex++; |
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231 | |
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232 | checkFile = new File(clientLogDir, getLogFileName(logFileIndex)); |
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233 | } |
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234 | while (checkFile.exists()); |
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235 | |
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236 | if (!logFile.renameTo(checkFile)) { |
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237 | Console.printerrln("could not rename log file " + logFile + " to " + checkFile + |
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238 | ". Will not perform log rotation."); |
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239 | } |
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240 | else { |
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241 | logFileIndex++; |
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242 | logFile = new File(clientLogDir, getLogFileName(-1)); |
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243 | } |
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244 | } |
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245 | |
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246 | /** |
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247 | * <p> |
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248 | * instantiates a writer to be used for writing messages into the log file. |
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249 | * </p> |
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250 | */ |
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251 | private void createLogWriter() throws IOException { |
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252 | FileOutputStream fis = new FileOutputStream(logFile); |
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253 | outputWriter = new PrintWriter(new OutputStreamWriter(fis, "UTF-8")); |
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254 | outputWriter.println("<?xml version=\"1.0\" encoding=\"UTF-8\"?>"); |
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255 | outputWriter.println |
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256 | ("<session xmlns=\"http://autoquest.informatik.uni-goettingen.de/httpexchange\" >"); |
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257 | } |
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258 | |
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259 | /** |
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260 | * <p> |
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261 | * closed the current writer if it is open. |
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262 | * </p> |
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263 | */ |
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264 | private void closeLogWriter() { |
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265 | if (outputWriter != null) { |
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266 | outputWriter.println("</session>"); |
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267 | outputWriter.flush(); |
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268 | outputWriter.close(); |
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269 | outputWriter = null; |
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270 | } |
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271 | } |
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272 | |
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273 | /* (non-Javadoc) |
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274 | * @see de.ugoe.cs.autoquest.htmlmonitor.HttpMonitorComponent#stop() |
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275 | */ |
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276 | @Override |
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277 | public synchronized void stop() { |
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278 | closeLogWriter(); |
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279 | rotateLogFile(); |
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280 | |
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281 | lastUpdate = System.currentTimeMillis(); |
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282 | } |
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283 | |
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284 | /** |
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285 | * <p> |
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286 | * return the time stamp of the last activity that happened on this writer. |
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287 | * </p> |
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288 | * |
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289 | * @return as described |
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290 | */ |
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291 | public long getLastUpdate() { |
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292 | return lastUpdate; |
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293 | } |
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294 | } |
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