Refactor Java agent to let applications manage the log handlers

[deliverable/lttng-ust.git] / doc / examples / java-log4j / Hello.java

diff --git a/doc/examples/java-log4j/Hello.java b/doc/examples/java-log4j/Hello.java
index c0393392e96bea7a9d402d088b441391fdd3bdb3..c51d4d4013b1d7d7979de3ec65ea6487cf1dcc14 100644 (file)
--- a/doc/examples/java-log4j/Hello.java
+++ b/doc/examples/java-log4j/Hello.java
@@ -1,4 +1,5 @@
 /*
+ * Copyright (C) 2015 - EfficiOS Inc., Alexandre Montplaisir <alexmonthy@efficios.com>
  * Copyright (C) 2014 - Christian Babeux <christian.babeux@efficios.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -20,47 +21,60 @@
  * IN THE SOFTWARE.
  */
 
+import java.io.IOException;
+
+import org.apache.log4j.Appender;
 import org.apache.log4j.BasicConfigurator;
 import org.apache.log4j.Logger;
-import org.lttng.ust.agent.LTTngAgent;
+import org.lttng.ust.agent.log4j.LttngLogAppender;
 
 /**
  * Example application using the LTTng-UST Java JUL agent.
  *
+ * @author Alexandre Montplaisir
  * @author Christian Babeux
  */
 public class Hello {
 
-       /* Of course :) */
-       private static final int answer = 42;
-
-       static Logger helloLog = Logger.getLogger(Hello.class);
-
-       private static LTTngAgent lttngAgent;
+       private static final Logger HELLO_LOG = Logger.getLogger(Hello.class);
 
        /**
         * Application start
         *
         * @param args
         *            Command-line arguments
-        * @throws Exception
+        * @throws IOException
+        * @throws InterruptedException
         */
-       public static void main(String args[]) throws Exception {
+       public static void main(String args[]) throws IOException, InterruptedException {
+               /* Start with the default Log4j configuration, which logs to console */
                BasicConfigurator.configure();
-               lttngAgent = LTTngAgent.getLTTngAgent();
+
+               /*
+                * Add a LTTng log appender to the logger, which will also send the
+                * logged events to UST.
+                */
+               Appender lttngAppender = new LttngLogAppender();
+               HELLO_LOG.addAppender(lttngAppender);
+
+               /*
+                * Here we've set up the appender programmatically, but it could also be
+                * defined at runtime, by reading a configuration file for example:
+                */
+               // 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 JUL Logger created before. */
-               helloLog.info("Hello World, the answer is " + answer);
+               /* Trigger a tracing event using the Log4j Logger created before. */
+               HELLO_LOG.info("Hello World, the answer is " + 42);
 
-               System.out.println("Firing hello delay in 5 seconds...");
+               System.out.println("Firing second event in 5 seconds...");
                Thread.sleep(5000);
-               helloLog.info("Hello World delayed...");
+               HELLO_LOG.info("Hello World delayed...");
 
-               lttngAgent.dispose();
+               lttngAppender.close();
        }
 }