/*
- * Copyright (C) 2015 - EfficiOS Inc., Alexandre Montplaisir <alexmonthy@efficios.com>
- * Copyright (C) 2014 - Christian Babeux <christian.babeux@efficios.com>
+ * SPDX-License-Identifier: MIT
*
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to
- * deal in the Software without restriction, including without limitation the
- * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
- * sell copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
- * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
- * IN THE SOFTWARE.
+ * Copyright (C) 2015 EfficiOS Inc.
+ * Copyright (C) 2015 Alexandre Montplaisir <alexmonthy@efficios.com>
+ * Copyright (C) 2014 Christian Babeux <christian.babeux@efficios.com>
*/
import java.io.IOException;
import org.apache.log4j.Appender;
import org.apache.log4j.BasicConfigurator;
import org.apache.log4j.Logger;
+import org.apache.log4j.Level;
import org.lttng.ust.agent.log4j.LttngLogAppender;
/**
- * Example application using the LTTng-UST Java JUL agent.
+ * Example application using the LTTng-UST Java log4j agent.
+ *
+ * <p>
+ * To obtain LTTng trace events, you should run the following sequence of
+ * commands:
+ * </p>
+ *
+ * <ul>
+ * <li>$ lttng create</li>
+ * <li>$ lttng enable-event -l -a</li>
+ * <li>$ lttng start</li>
+ * <li>(run this program)</li>
+ * <li>$ lttng stop</li>
+ * <li>$ lttng view</li>
+ * <li>$ lttng destroy</li>
+ * </ul>
*
* @author Alexandre Montplaisir
* @author Christian Babeux
* @param args
* Command-line arguments
* @throws IOException
- * @throws InterruptedException
+ * If the required native libraries cannot be found. You may
+ * have to specify "-Djava.library.path=..." on the "java"
+ * command line.
*/
- public static void main(String args[]) throws IOException, InterruptedException {
+ public static void main(String args[]) throws IOException {
+
+ /*
+ * Set lowest level to make sure all event levels are logged.
+ * Any jar can override the default log4j rootLogger level
+ * and a logger with no explicit level defaults to the non-null
+ * parent level. Events could be ignored if the inherited value
+ * is to low.
+ * e.g BSF -> https://issues.apache.org/jira/browse/BSF-24
+ */
+ HELLO_LOG.setLevel(Level.ALL);
+
/* Start with the default Log4j configuration, which logs to console */
BasicConfigurator.configure();
/*
- * Add a LTTng log appender to the logger, which will also send the
- * logged events to UST.
+ * Instantiate a LTTng log appender and attach it to the logger, which
+ * will now send the logged events to UST.
*/
Appender lttngAppender = new LttngLogAppender();
HELLO_LOG.addAppender(lttngAppender);
*/
// PropertyConfigurator.configure(fileName);
- /*
- * Gives you time to do some lttng commands before any event is hit.
- */
- Thread.sleep(5000);
-
- /* Trigger a tracing event using the Log4j Logger created before. */
+ /* Trigger some tracing events using the Log4j Logger created before. */
HELLO_LOG.info("Hello World, the answer is " + 42);
+ HELLO_LOG.info("Another info event");
+ HELLO_LOG.error("An error event");
- System.out.println("Firing second event in 5 seconds...");
- Thread.sleep(5000);
- HELLO_LOG.info("Hello World delayed...");
-
+ /* Cleanup */
+ HELLO_LOG.removeAppender(lttngAppender);
lttngAppender.close();
}
}