doc/examples/java-jul/ApplicationContextExample.java

   1 /*
   2  * Copyright (C) 2016 - EfficiOS Inc., Alexandre Montplaisir <alexmonthy@efficios.com>
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a copy
   5  * of this software and associated documentation files (the "Software"), to
   6  * deal in the Software without restriction, including without limitation the
   7  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
   8  * sell copies of the Software, and to permit persons to whom the Software is
   9  * furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  17  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  19  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  20  * IN THE SOFTWARE.
  21  */
  22
  23 import java.io.IOException;
  24 import java.util.logging.Handler;
  25 import java.util.logging.Logger;
  26
  27 import org.lttng.ust.agent.context.ContextInfoManager;
  28 import org.lttng.ust.agent.context.IContextInfoRetriever;
  29 import org.lttng.ust.agent.jul.LttngLogHandler;
  30
  31 /**
  32  * Example program defining a application context retriever, which allows
  33  * attaching application-defined contexts to trace events.
  34  *
  35  * FIXME Use custom context names, and several names/types
  36  *
  37  * <p>
  38  * Usage:
  39  * <ul>
  40  * <li>$ lttng create</li>
  41  * <li>$ lttng enable-event -j -a</li>
  42  * <li>$ lttng add-context -j -t '$app.myprovider:mystringcontext'</li>
  43  * <li>$ lttng add-context -j -t '$app.myprovider:myshortcontext'</li>
  44  * <li>$ lttng start</li>
  45  * <li>(run this program)</li>
  46  * <li>$ lttng stop</li>
  47  * <li>$ lttng view</li>
  48  * <li>$ lttng destroy</li>
  49  * </ul>
  50  * </p>
  51  *
  52  * The events present in the resulting trace should carry the context
  53  * information defined in the example retriever.
  54  *
  55  * @author Alexandre Montplaisir
  56  */
  57 public class ApplicationContextExample {
  58
  59         /** Class-wide JUL logger object */
  60         private static final Logger LOGGER = Logger.getLogger(ApplicationContextExample.class.getName());
  61
  62         private static final String RETRIEVER_NAME = "myprovider";
  63         private static final String CONTEXT_NAME_STRING = "mystringcontext";
  64         private static final String CONTEXT_NAME_SHORT = "myshortcontext";
  65
  66         private static class ExampleContextInfoRetriever implements IContextInfoRetriever {
  67
  68                 @Override
  69                 public Object retrieveContextInfo(String key) {
  70                         if (CONTEXT_NAME_SHORT.equals(key)) {
  71                                 return (short) 42;
  72                         } else if (CONTEXT_NAME_STRING.equals(key)) {
  73                                 return "context-value!";
  74                         } else {
  75                                 return null;
  76                         }
  77                 }
  78
  79         }
  80
  81         /**
  82          * Application start
  83          *
  84          * @param args
  85          *            Command-line arguments
  86          * @throws IOException
  87          * @throws InterruptedException
  88          */
  89         public static void main(String args[]) throws IOException, InterruptedException {
  90                 /* Instantiate and attach a logger object */
  91                 Handler lttngHandler = new LttngLogHandler();
  92                 LOGGER.addHandler(lttngHandler);
  93
  94                 /* Instantiate and register the context retriever */
  95                 IContextInfoRetriever cir = new ExampleContextInfoRetriever();
  96                 ContextInfoManager.getInstance().registerContextInfoRetriever(RETRIEVER_NAME, cir);
  97
  98                 /*
  99                  * Make sure you have a LTTng session running with the appropriate
 100                  * events and contexts enabled! See the class Javadoc.
 101                  */
 102
 103                 /* Trigger a tracing event using the JUL Logger created before. */
 104                 LOGGER.info("Log event #1");
 105                 LOGGER.warning("Log event #2");
 106                 LOGGER.severe("Log event #3");
 107
 108                 /* Unregister our context retriever, and dispose the log handler */
 109                 ContextInfoManager.getInstance().unregisterContextInfoRetriever(RETRIEVER_NAME);
 110                 lttngHandler.close();
 111         }
 112 }