[1374] | 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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[1561] | 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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[1374] | 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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[1444] | 255 | outputWriter.println |
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[1561] | 256 | ("<session xmlns=\"http://autoquest.informatik.uni-goettingen.de/httpexchange\" >"); |
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[1374] | 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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