[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.proxy; |
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| 16 | |
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| 17 | import java.nio.ByteBuffer; |
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| 18 | import java.util.ArrayList; |
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| 19 | import java.util.HashMap; |
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| 20 | import java.util.List; |
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| 21 | import java.util.Map; |
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| 22 | import java.util.Timer; |
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| 23 | import java.util.TimerTask; |
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| 24 | import java.util.logging.Level; |
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| 25 | |
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| 26 | import javax.servlet.http.HttpServletRequest; |
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| 27 | import javax.servlet.http.HttpServletResponse; |
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| 28 | |
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| 29 | import de.ugoe.cs.autoquest.httpmonitor.HttpMonitorComponent; |
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| 30 | import de.ugoe.cs.autoquest.httpmonitor.HttpMonitorException; |
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| 31 | import de.ugoe.cs.autoquest.httpmonitor.HttpMonitorExchangeHandler; |
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| 32 | import de.ugoe.cs.autoquest.httpmonitor.exchange.Status; |
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| 33 | import de.ugoe.cs.util.console.Console; |
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| 34 | |
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| 35 | /** |
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| 36 | * <p> |
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| 37 | * TODO update comment |
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| 38 | * The log manager handles different {@link HttpMonitorOutputWriter}s to perform the logging |
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| 39 | * of recorded messages. It initializes a new writer if the first message for a specific |
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| 40 | * client is received and it closes a writer if for a specific period of time no further message |
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| 41 | * of the same client was received. The writers themselves consider log rotation. For handling |
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| 42 | * messages, the {@link HttpMonitorExchangeHandler} mechanism provided by the |
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| 43 | * {@link HttpMonitorServer} is used. |
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| 44 | * </p> |
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| 45 | * |
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| 46 | * @author Patrick Harms |
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| 47 | */ |
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| 48 | class ExchangeListenerManager implements HttpMonitorComponent { |
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| 49 | |
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| 50 | /** |
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| 51 | * the timeout after which a writer of an inactive client is closed |
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| 52 | */ |
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| 53 | private static final int SESSION_TIMEOUT = 10 * 60 * 1000; |
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| 54 | |
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| 55 | /** |
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| 56 | * |
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| 57 | */ |
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| 58 | private HttpMonitorExchangeHandler exchangeHandler; |
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| 59 | |
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| 60 | /** |
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| 61 | * the mapping of client ids to the respective writers. |
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| 62 | */ |
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| 63 | private Map<HttpServletRequest, ExchangeListener> listeners; |
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| 64 | |
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| 65 | /** |
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| 66 | * a timer used to detect exchange timeouts |
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| 67 | */ |
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| 68 | private Timer listenerTimer; |
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| 69 | |
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| 70 | /** |
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| 71 | * |
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| 72 | * |
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| 73 | */ |
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| 74 | ExchangeListenerManager(HttpMonitorExchangeHandler exchangeHandler) { |
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| 75 | this.exchangeHandler = exchangeHandler; |
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| 76 | } |
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| 77 | |
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| 78 | /* (non-Javadoc) |
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| 79 | * @see de.ugoe.cs.autoquest.htmlmonitor.HtmlMonitorComponent#init() |
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| 80 | */ |
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| 81 | @Override |
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| 82 | public synchronized void init() throws IllegalStateException, HttpMonitorException { |
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| 83 | Console.traceln(Level.FINER, "initializing exchange listener manager"); |
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| 84 | |
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| 85 | if (listeners != null) { |
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| 86 | throw new IllegalStateException("already initialized"); |
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| 87 | } |
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| 88 | |
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| 89 | listeners = new HashMap<HttpServletRequest, ExchangeListener>(); |
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| 90 | listenerTimer = new Timer(); |
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| 91 | } |
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| 92 | |
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| 93 | /* (non-Javadoc) |
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| 94 | * @see de.ugoe.cs.autoquest.htmlmonitor.HtmlMonitorComponent#start() |
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| 95 | */ |
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| 96 | @Override |
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| 97 | public synchronized void start() throws IllegalStateException, HttpMonitorException { |
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| 98 | Console.traceln(Level.FINER, "starting exchange listener manager"); |
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| 99 | |
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| 100 | if (listeners == null) { |
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| 101 | throw new IllegalStateException("not initialized"); |
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| 102 | } |
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| 103 | |
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| 104 | listenerTimer.schedule |
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| 105 | (new ListenerMonitorTimerTask(), SESSION_TIMEOUT / 2, SESSION_TIMEOUT / 2); |
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| 106 | } |
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| 107 | |
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| 108 | /* (non-Javadoc) |
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| 109 | * @see de.ugoe.cs.autoquest.htmlmonitor.HtmlMonitorComponent#stop() |
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| 110 | */ |
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| 111 | @Override |
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| 112 | public synchronized void stop() { |
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| 113 | Console.traceln(Level.FINER, "stopping exchange listener manager"); |
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| 114 | |
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| 115 | if (listenerTimer != null) { |
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| 116 | listenerTimer.cancel(); |
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| 117 | } |
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| 118 | |
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| 119 | if (listeners != null) { |
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| 120 | for (ExchangeListener listener : listeners.values()) { |
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| 121 | listener.onFinish(Status.TIMEOUT); |
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| 122 | } |
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| 123 | } |
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| 124 | |
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| 125 | listeners = null; |
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| 126 | } |
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| 127 | |
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| 128 | /** |
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| 129 | * |
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| 130 | */ |
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| 131 | public void onRequest(HttpServletRequest request) throws IllegalStateException { |
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| 132 | ensureListener(request).onRequest(request); |
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| 133 | } |
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| 134 | |
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| 135 | /** |
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| 136 | * |
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| 137 | */ |
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| 138 | public void onRequestContent(HttpServletRequest request, ByteBuffer data) |
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| 139 | throws IllegalStateException |
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| 140 | { |
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| 141 | ensureListener(request).onRequestContent(data); |
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| 142 | } |
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| 143 | |
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| 144 | /** |
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| 145 | * |
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| 146 | */ |
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| 147 | public void onResponse(HttpServletRequest request, HttpServletResponse response) |
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| 148 | throws IllegalStateException |
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| 149 | { |
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| 150 | ensureListener(request).onResponse(response); |
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| 151 | } |
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| 152 | |
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| 153 | /** |
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| 154 | * |
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| 155 | */ |
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| 156 | public void onResponseContent(HttpServletRequest request, ByteBuffer data) |
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| 157 | throws IllegalStateException |
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| 158 | { |
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| 159 | ensureListener(request).onResponseContent(data); |
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| 160 | } |
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| 161 | |
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| 162 | /** |
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| 163 | * |
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| 164 | */ |
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| 165 | public void onFinish(HttpServletRequest request, Status status) throws IllegalStateException { |
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| 166 | ensureListener(request).onFinish(status); |
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| 167 | Console.traceln(Level.FINEST, "removing exchange listener for " + request); |
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| 168 | listeners.remove(request); |
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| 169 | } |
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| 170 | |
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| 171 | /** |
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| 172 | * |
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| 173 | */ |
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| 174 | private ExchangeListener ensureListener(HttpServletRequest request) { |
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| 175 | ExchangeListener listener = listeners.get(request); |
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| 176 | |
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| 177 | if (listener == null) { |
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| 178 | synchronized (this) { |
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| 179 | listener = listeners.get(request); |
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| 180 | if (listener == null) { |
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| 181 | Console.traceln(Level.FINEST, "creating exchange listener for " + request); |
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| 182 | listener = new ExchangeListener(exchangeHandler); |
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| 183 | listeners.put(request, listener); |
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| 184 | } |
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| 185 | } |
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| 186 | } |
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| 187 | |
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| 188 | return listener; |
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| 189 | } |
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| 190 | |
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| 191 | /** |
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| 192 | * <p> |
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| 193 | * internal timer task used for detecting session timeouts of clients |
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| 194 | * </p> |
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| 195 | * |
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| 196 | * @author Patrick Harms |
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| 197 | */ |
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| 198 | public class ListenerMonitorTimerTask extends TimerTask { |
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| 199 | |
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| 200 | /* (non-Javadoc) |
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| 201 | * @see java.lang.Runnable#run() |
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| 202 | */ |
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| 203 | @Override |
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| 204 | public void run() { |
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| 205 | synchronized (ExchangeListenerManager.this) { |
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| 206 | List<HttpServletRequest> timeoutRequests = new ArrayList<HttpServletRequest>(); |
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| 207 | for (Map.Entry<HttpServletRequest, ExchangeListener> entry : listeners.entrySet()) { |
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| 208 | ExchangeListener listener = entry.getValue(); |
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| 209 | |
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| 210 | if (System.currentTimeMillis() - listener.getLastUpdate() > SESSION_TIMEOUT) { |
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| 211 | timeoutRequests.add(entry.getKey()); |
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| 212 | } |
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| 213 | } |
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| 214 | |
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| 215 | for (HttpServletRequest request : timeoutRequests) { |
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| 216 | ExchangeListener listener = listeners.remove(request); |
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| 217 | listener.onFinish(Status.TIMEOUT); |
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| 218 | } |
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| 219 | } |
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| 220 | } |
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| 221 | |
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| 222 | } |
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| 223 | |
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| 224 | } |
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