| 1 | /* |
| 2 | * Copyright (C) 2015 - EfficiOS Inc., Alexandre Montplaisir <alexmonthy@efficios.com> |
| 3 | * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com> |
| 4 | * |
| 5 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 6 | * of this software and associated documentation files (the "Software"), to |
| 7 | * deal in the Software without restriction, including without limitation the |
| 8 | * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or |
| 9 | * sell copies of the Software, and to permit persons to whom the Software is |
| 10 | * furnished to do so, subject to the following conditions: |
| 11 | * |
| 12 | * The above copyright notice and this permission notice shall be included in |
| 13 | * all copies or substantial portions of the Software. |
| 14 | * |
| 15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 16 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 17 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 18 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 19 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| 20 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| 21 | * IN THE SOFTWARE. |
| 22 | */ |
| 23 | |
| 24 | import java.io.IOException; |
| 25 | import java.util.logging.Handler; |
| 26 | import java.util.logging.Logger; |
| 27 | |
| 28 | import org.lttng.ust.agent.jul.LttngLogHandler; |
| 29 | |
| 30 | /** |
| 31 | * Example application using the LTTng-UST Java JUL agent. |
| 32 | * |
| 33 | * <p> |
| 34 | * Basically all that is required is to instantiate a {@link LttngLogHandler} |
| 35 | * and to attach it to a JUL {@link Logger}. Then use the Logger normally to log |
| 36 | * messages, which will be sent to UST as trace events. |
| 37 | * <p> |
| 38 | * </p> |
| 39 | * {@link Logger} names are used as event names on the UST side. This means that |
| 40 | * by enabling/disabling certain events in the tracing session, you are |
| 41 | * effectively enabling and disabling Loggers on the Java side. Note that this |
| 42 | * applies only to {@link LttngLogHandler}'s. If other handlers are attached to |
| 43 | * the Logger, those will continue logging events normally. |
| 44 | * </p> |
| 45 | * |
| 46 | * @author Alexandre Montplaisir |
| 47 | * @author David Goulet |
| 48 | */ |
| 49 | public class Hello { |
| 50 | |
| 51 | /** Class-wide JUL logger object */ |
| 52 | private static final Logger LOGGER = Logger.getLogger(Hello.class.getName()); |
| 53 | |
| 54 | /** |
| 55 | * Application start |
| 56 | * |
| 57 | * @param args |
| 58 | * Command-line arguments |
| 59 | * @throws IOException |
| 60 | * @throws InterruptedException |
| 61 | */ |
| 62 | public static void main(String args[]) throws IOException, InterruptedException { |
| 63 | |
| 64 | /* Instantiate a LTTngLogHandler object, and attach it to our logger */ |
| 65 | Handler lttngHandler = new LttngLogHandler(); |
| 66 | LOGGER.addHandler(lttngHandler); |
| 67 | |
| 68 | /* |
| 69 | * Gives you time to do some lttng commands before any event is hit. |
| 70 | */ |
| 71 | Thread.sleep(5000); |
| 72 | |
| 73 | /* Trigger a tracing event using the JUL Logger created before. */ |
| 74 | LOGGER.info("Hello World, the answer is " + 42); |
| 75 | |
| 76 | /* |
| 77 | * From this point on, the above message will be collected in the trace |
| 78 | * if the event "Hello" is enabled for the JUL domain using the lttng |
| 79 | * command line or the lttng-ctl API. For instance: |
| 80 | * |
| 81 | * $ lttng enable-event -j Hello |
| 82 | */ |
| 83 | |
| 84 | /* |
| 85 | * A new logger is created here and fired after. Typically with JUL, you |
| 86 | * use one static Logger per class. This example here can represent a |
| 87 | * class being lazy-loaded later in the execution of the application. |
| 88 | * |
| 89 | * The agent has an internal timer that is fired every 5 seconds in |
| 90 | * order to enable events that were not found at first but might need to |
| 91 | * be enabled when a new Logger appears. Unfortunately, there is no way |
| 92 | * right now to get notified of that so we have to actively poll. |
| 93 | * |
| 94 | * Using the --all command for instance, it will make this Logger |
| 95 | * available in a LTTng trace after the internal agent's timer is fired. |
| 96 | * (lttng enable-event -j -a). |
| 97 | */ |
| 98 | Logger helloLogDelayed = Logger.getLogger("hello_delay"); |
| 99 | |
| 100 | /* |
| 101 | * Attach a handler to this new logger. |
| 102 | * |
| 103 | * Using the same handler as before would also work. |
| 104 | */ |
| 105 | Handler lttngHandler2 = new LttngLogHandler(); |
| 106 | helloLogDelayed.addHandler(lttngHandler2); |
| 107 | |
| 108 | System.out.println("Firing hello delay in 10 seconds..."); |
| 109 | Thread.sleep(10000); |
| 110 | helloLogDelayed.info("Hello World delayed..."); |
| 111 | |
| 112 | System.out.println("Cleaning Hello"); |
| 113 | |
| 114 | /* |
| 115 | * Do not forget to close() all handlers so that the agent can shutdown |
| 116 | * and the session daemon socket gets cleaned up explicitly. |
| 117 | */ |
| 118 | lttngHandler.close(); |
| 119 | lttngHandler2.close(); |
| 120 | } |
| 121 | } |