[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 javax.servlet.Servlet; |
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| 18 | |
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| 19 | import de.ugoe.cs.util.console.Console; |
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| 20 | |
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| 21 | /** |
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| 22 | * <p> |
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| 23 | * The HTTP monitor starts a web server ({@link HttpMonitorServer}) that receives exchanges |
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[1991] | 24 | * of the HTTP proxy. In addition, it provides via get a unique ordering id for requests and |
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| 25 | * responses that can be used by the proxies when creating the exchanges. The exchanges are |
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| 26 | * logged using the {@link HttpMonitorLogManager}. The class assures that on shutdown e.g. caused |
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| 27 | * by CTRL-C the server and the log manager are stopped correctly. |
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[1374] | 28 | * </p> |
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| 29 | * |
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| 30 | * @author Patrick Harms |
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| 31 | */ |
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| 32 | public class HttpMonitor implements HttpMonitorComponent { |
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| 33 | |
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| 34 | /** |
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| 35 | * the port on which the webserver shall listen. Defaults to 8090. |
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| 36 | */ |
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| 37 | private int port = 8090; |
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| 38 | |
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| 39 | /** |
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| 40 | * the web server receiving the exchanges |
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| 41 | */ |
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| 42 | private HttpMonitorServer server; |
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| 43 | |
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| 44 | /** |
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| 45 | * the directory into which the log files shall be written |
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| 46 | */ |
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| 47 | private String logFileBaseDir; |
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| 48 | |
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| 49 | /** |
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| 50 | * the log manager being responsible for performing the logging |
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| 51 | */ |
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| 52 | private HttpMonitorLogManager logManager; |
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| 53 | |
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| 54 | /** |
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[1991] | 55 | * the id generator used for getting new unique ids |
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| 56 | */ |
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| 57 | private IdGenerator idGenerator; |
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| 58 | |
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| 59 | /** |
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[1374] | 60 | * the thread needed to handle CTRL-C events |
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| 61 | */ |
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| 62 | private Thread shutdownHook; |
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| 63 | |
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| 64 | /** |
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| 65 | * <p> |
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| 66 | * initializes the monitor with the command line arguments. Those may be the log directory |
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| 67 | * as first argument and the port to listen on as second |
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| 68 | * </p> |
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| 69 | * |
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| 70 | * @param commandLineArguments the command line arguments when starting the monitor using |
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| 71 | * the {@link Runner} |
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| 72 | */ |
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| 73 | public HttpMonitor(String[] commandLineArguments) { |
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| 74 | if (commandLineArguments.length > 0) { |
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| 75 | this.logFileBaseDir = commandLineArguments[0]; |
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| 76 | Console.println("putting logs into directory " + this.logFileBaseDir); |
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| 77 | } |
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| 78 | |
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| 79 | if (commandLineArguments.length > 1) { |
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| 80 | try { |
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| 81 | this.port = Integer.parseInt(commandLineArguments[1]); |
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| 82 | } |
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| 83 | catch (NumberFormatException e) { |
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| 84 | Console.println("ignoring invalid port specification " + commandLineArguments[1]); |
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| 85 | } |
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| 86 | Console.println("listening on port " + this.port); |
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| 87 | } |
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| 88 | } |
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| 89 | |
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| 90 | /* (non-Javadoc) |
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| 91 | * @see de.ugoe.cs.autoquest.htmlmonitor.HttpMonitorComponent#init() |
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| 92 | */ |
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| 93 | @Override |
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| 94 | public synchronized void init() throws HttpMonitorException { |
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| 95 | if (server != null) { |
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| 96 | throw new IllegalStateException("already initialized."); |
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| 97 | } |
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| 98 | |
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| 99 | try { |
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[1991] | 100 | idGenerator = new SimpleIdGenerator(); |
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| 101 | idGenerator.init(); |
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| 102 | |
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[1374] | 103 | logManager = new HttpMonitorLogManager(logFileBaseDir); |
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| 104 | logManager.init(); |
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| 105 | |
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[1991] | 106 | Servlet servlet = new HttpMonitorServlet(logManager, idGenerator); |
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[1374] | 107 | server = new HttpMonitorServer(port, servlet); |
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| 108 | server.init(); |
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| 109 | |
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| 110 | shutdownHook = new Thread(new ShutdownHook(server, logManager)); |
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| 111 | } |
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| 112 | catch (HttpMonitorException e) { |
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| 113 | Console.printerrln("could not initialize HTTP monitor: " + e); |
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| 114 | Console.logException(e); |
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| 115 | } |
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| 116 | } |
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| 117 | |
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| 118 | /* (non-Javadoc) |
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| 119 | * @see de.ugoe.cs.autoquest.htmlmonitor.HttpMonitorComponent#start() |
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| 120 | */ |
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| 121 | @Override |
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| 122 | public synchronized void start() { |
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| 123 | if (server == null) { |
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| 124 | throw new IllegalStateException("not initialized."); |
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| 125 | } |
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| 126 | |
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| 127 | try { |
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| 128 | Runtime.getRuntime().addShutdownHook(shutdownHook); |
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[1991] | 129 | idGenerator.start(); |
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[1374] | 130 | logManager.start(); |
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| 131 | server.start(); |
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| 132 | } |
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| 133 | catch (HttpMonitorException e) { |
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| 134 | Console.printerrln("could not start HTTP monitor: " + e); |
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| 135 | Console.logException(e); |
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| 136 | } |
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| 137 | } |
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| 138 | |
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| 139 | /* (non-Javadoc) |
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| 140 | * @see de.ugoe.cs.autoquest.htmlmonitor.HttpMonitorComponent#stop() |
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| 141 | */ |
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| 142 | @Override |
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| 143 | public synchronized void stop() { |
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| 144 | if (server == null) { |
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| 145 | throw new IllegalStateException("not initialized."); |
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| 146 | } |
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| 147 | |
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| 148 | Runtime.getRuntime().removeShutdownHook(shutdownHook); |
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| 149 | server.stop(); |
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| 150 | logManager.stop(); |
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[1991] | 151 | idGenerator.stop(); |
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[1374] | 152 | |
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| 153 | server = null; |
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| 154 | logManager = null; |
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[1991] | 155 | idGenerator = null; |
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[1374] | 156 | } |
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| 157 | |
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| 158 | } |
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