X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;f=contents%2Fusing-lttng%2Finstrumenting%2Fjava-application.md;h=af516647d114bf7f04ace80e0ac4703b304694ef;hb=3b5b45ec9eeae44744acb849c1a04eddd9d971c4;hp=51809807288ac023b700a7c4dc7ea2a02a4e65a4;hpb=5e0cbfb01373c18e521217342fd8a9159cc186b1;p=lttng-docs.git
diff --git a/contents/using-lttng/instrumenting/java-application.md b/contents/using-lttng/instrumenting/java-application.md
index 5180980..af51664 100644
--- a/contents/using-lttng/instrumenting/java-application.md
+++ b/contents/using-lttng/instrumenting/java-application.md
@@ -3,29 +3,42 @@ id: java-application
---
LTTng-UST provides a _logging_ back-end for Java applications using
-Java Util Logging (JUL). This back-end is called the _LTTng-UST JUL agent_ and is
-responsible for communications with an LTTng session daemon.
+either
+java.util.logging
+(JUL), or
+Apache log4j 1.2.
+This back-end is called the _LTTng-UST Java agent_, and is responsible
+for communications with an LTTng session daemon.
-From the user's point of view, once the LTTng-UST JUL agent has been
-initialized, JUL loggers may be created and used as usual. The agent
-adds its own handler to the _root logger_, so that all loggers may
-generate LTTng events with no effort.
+
+
+ Note:The latest stable version of LTTng
+ does not support Log4j 2.
+
+
-Common JUL features are supported using the `lttng` tool
+From the user's point of view, once the LTTng-UST Java agent has been
+initialized, JUL and log4j loggers may be created and used as usual.
+The agent adds its own handler to the _root logger_, so that all
+loggers may generate LTTng events with no effort.
+
+Common JUL/log4j features are supported using the `lttng` tool
(see [Controlling tracing](#doc-controlling-tracing)):
* listing all logger names
* enabling/disabling events per logger name
- * JUL log levels
+ * JUL/log4j log levels
-Here's an example:
+Here's an example using **`java.util.logging`**:
~~~ java
import java.util.logging.Logger;
-import org.lttng.ust.jul.LTTngAgent;
+import org.lttng.ust.agent.LTTngAgent;
public class Test
{
+ private static final int answer = 42;
+
public static void main(String[] argv) throws Exception
{
// create a logger
@@ -38,7 +51,7 @@ public class Test
logger.info("some info");
logger.warning("some warning");
Thread.sleep(500);
- logger.finer("finer information...");
+ logger.finer("finer information; the answer is " + answer);
Thread.sleep(123);
logger.severe("error!");
@@ -48,26 +61,63 @@ public class Test
}
~~~
-The LTTng-UST JUL agent Java classes are packaged in a JAR file named
-`liblttng-ust-jul.jar`. It is typically located in
-`/usr/lib/lttng/java`. To compile the snippet above
+Here's the same example, this time using **log4j**:
+
+~~~ java
+import org.apache.log4j.Logger;
+import org.apache.log4j.BasicConfigurator;
+import org.lttng.ust.agent.LTTngAgent;
+
+public class Test
+{
+ private static final int answer = 42;
+
+ public static void main(String[] argv) throws Exception
+ {
+ // create and configure a logger
+ Logger logger = Logger.getLogger(Test.class);
+ BasicConfigurator.configure();
+
+ // call this as soon as possible (before logging)
+ LTTngAgent lttngAgent = LTTngAgent.getLTTngAgent();
+
+ // log at will!
+ logger.info("some info");
+ logger.warn("some warning");
+ Thread.sleep(500);
+ logger.debug("debug information; the answer is " + answer);
+ Thread.sleep(123);
+ logger.error("error!");
+ logger.fatal("fatal error!");
+
+ // not mandatory, but cleaner
+ lttngAgent.dispose();
+ }
+}
+~~~
+
+The LTTng-UST Java agent classes are packaged in a JAR file named
+`liblttng-ust-agent.jar`. It is typically located in
+`/usr/lib/lttng/java`. To compile the snippets above
(saved as `Test.java`), do:
-javac -cp /usr/lib/lttng/java/liblttng-ust-jul.jar Test.java
+javac -cp /usr/lib/lttng/java/liblttng-ust-agent.jar:$LOG4JCP Test.java
-You can run the resulting compiled class:
+where `$LOG4JCP` is the log4j 1.2 JAR file path, if you're using log4j.
+
+You can run the resulting compiled class like this:
-java -cp /usr/lib/lttng/java/liblttng-ust-jul.jar:. Test
+java -cp /usr/lib/lttng/java/liblttng-ust-agent.jar:$LOG4JCP:. Test
Note:OpenJDK 7
is used for development and continuous integration, thus this
- version is directly supported. However, the LTTng-UST JUL agent has
+ version is directly supported. However, the LTTng-UST Java agent has
also been tested with OpenJDK 6.