The agent can be built in three different configurations:

1) Java agent with JUL support:

$ ./configure --enable-java-agent-jul

2) Java agent with Log4j support:

$ export CLASSPATH=$CLASSPATH:/path/to/log4j.jar
$ ./configure --enable-java-agent-log4j

3) Java agent with JUL + Log4j support

$ export CLASSPATH=$CLASSPATH:/path/to/log4j.jar
$ ./configure --enable-java-agent-all

To build the agent with log4j support, make sure that the log4j jar
is in your Java classpath.

The configure script will automatically detect the appropriate Java
binaries to use in order to build the Java agent.

Enabling the JUL support will build a "lttng-ust-agent-jul.jar" file. Enabling
the log4j support will build a "lttng-ust-agent-log4j.jar". Both of these jars
depend on a third "lttng-ust-agent-common.jar", which will always be built.

All these archives will be installed in the arch-agnostic "$prefix/share/java"
path, e.g: "/usr/share/java". You need to make sure the .jar for the logging
API you want to use (either lttng-ust-agent-jul.jar or -log4j.jar) is on your
application's classpath.

Both logging libraries also require an architecture-specific shared object
(e.g: "liblttng-ust-jul-jni.so"), which is installed by the build system when
doing "make install". Make sure that your Java application can find this shared
object with the "java.library.path" property.

In order to enable the agent in your Java application, you simply have to add
this as early as you can in the runtime process.

import org.lttng.ust.agent.LTTngAgent;
[...]
	private static LTTngAgent lttngAgent;
	[...]
	lttngAgent = LTTngAgent.getLTTngAgent();

This will initialize automatically the singleton LTTngAgent, and will
return when the session daemon registration is done. If no session daemon is
available, the execution will continue and the agent will retry every
3 seconds.