jetty-documentation/src/main/asciidoc/administration/logging/example-apache-log4j.adoc - jetty - Git at Google

 //  ========================================================================
 //  Copyright (c) 1995-2017 Mort Bay Consulting Pty. Ltd.
 //  ========================================================================
 //  All rights reserved. This program and the accompanying materials
 //  are made available under the terms of the Eclipse Public License v1.0
 //  and Apache License v2.0 which accompanies this distribution.
 //
 //      The Eclipse Public License is available at
 //      http://www.eclipse.org/legal/epl-v10.html
 //
 //      The Apache License v2.0 is available at
 //      http://www.opensource.org/licenses/apache2.0.php
 //
 //  You may elect to redistribute this code under either of these licenses.
 //  ========================================================================

 [[example-logging-log4j]]
 === Example: Logging with Apache Log4j

 It is possible to have the Jetty Server logging configured so that Log4j controls the output of logging events produced by Jetty.
 This is accomplished by configuring Jetty for logging to http://logging.apache.org/log4j/[Apache Log4j] via http://slf4j.org/manual.html[Slf4j] and the http://slf4j.org/manual.html#swapping[Slf4j binding layer for Log4j].

 A convenient replacement `logging` module has been created to bootstrap your `${jetty.base}` directory for logging with log4j.

 [source, screen, subs="{sub-order}"]
 ....
 [mybase]$ mkdir modules
 [mybase]$ cd modules

 [modules]$ curl -O https://raw.githubusercontent.com/jetty-project/logging-modules/master/log4j-1.2/logging.mod
   % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                  Dload  Upload   Total   Spent    Left  Speed
 100   720  100   720    0     0   2188      0 --:--:-- --:--:-- --:--:--  2188
 [modules]$ cd ..

 [mybase]$ java -jar /opt/jetty-dist/start.jar --add-to-start=logging
 INFO: logging         initialised in ${jetty.base}/start.ini (appended)
 MKDIR: ${jetty.base}/logs
 DOWNLOAD: http://central.maven.org/maven2/org/slf4j/slf4j-api/1.6.6/slf4j-api-1.6.6.jar to lib/logging/slf4j-api-1.6.6.jar
 DOWNLOAD: http://central.maven.org/maven2/org/slf4j/slf4j-log4j12/1.6.6/slf4j-log4j12-1.6.6.jar to lib/logging/slf4j-log4j12-1.6.6.jar
 DOWNLOAD: http://central.maven.org/maven2/log4j/log4j/1.2.17/log4j-1.2.17.jar to lib/logging/log4j-1.2.17.jar
 DOWNLOAD: https://raw.githubusercontent.com/jetty-project/logging-modules/master/log4j-1.2/log4j.properties to resources/log4j.properties
 DOWNLOAD: https://raw.githubusercontent.com/jetty-project/logging-modules/master/log4j-1.2/jetty-logging.properties to resources/jetty-logging.properties
 INFO: resources       initialised transitively
 INFO: resources       enabled in     ${jetty.base}/start.ini

 [mybase]$ java -jar /opt/jetty-dist/start.jar
 ....

 The replacement `logging.mod` performs a number of tasks.

 .  `mybase` is a `${jetty.base}` directory.
 .  The jetty-distribution is unpacked (and untouched) into `/opt/jetty-dist/` and becomes the `${jetty.home}` directory for this demonstration.
 .  The `curl` command downloads the replacement `logging.mod` and puts it into the `${jetty.base}/modules/` directory for use by mybase only.
 .  The `start.jar --add-to-start=logging` command performs a number of steps to make the logging module available to the `${jetty.base}` configuration.
 ..  The `--module=logging` command is added to the `${jetty.base}/start.ini` configuration.
 ..  Required `${jetty.base}` directories are created: `${jetty.base}/logs` and `${jetty.base}/resources`
 ..  Required libraries are downloaded (if not present already): slf4j-api, slf4j-log4j, and log4j itself.
 * The libraries are put in the `${jetty.base}/lib/logging/` directory.
 ..  Required configuration files are downloaded (if not present already): `jetty-logging.properties`, and `log4j.properties`
 * The configuration files are placed in the `${jetty.base}/resources/` directory.

 At this point the Jetty `mybase` is configured so that the Jetty server itself will log using log4j, using the log4j configuration found in `mybase/resources/log4j.properties`.

 The server classpath can be verified by using the `start.jar --list-config` command.

 In essence, Jetty is now configured to emit its own logging events to slf4j, and slf4j itself is using the static log binder found in `slf4j-log4j12.jar`, making all Jetty + Slf4j + Log4j events emitted by the Jetty server go to Log4j for routing (to console, file, syslog, etc...).
	// ========================================================================
	// Copyright (c) 1995-2017 Mort Bay Consulting Pty. Ltd.
	// ========================================================================
	// All rights reserved. This program and the accompanying materials
	// are made available under the terms of the Eclipse Public License v1.0
	// and Apache License v2.0 which accompanies this distribution.
	//
	// The Eclipse Public License is available at
	// http://www.eclipse.org/legal/epl-v10.html
	//
	// The Apache License v2.0 is available at
	// http://www.opensource.org/licenses/apache2.0.php
	//
	// You may elect to redistribute this code under either of these licenses.
	// ========================================================================

	[[example-logging-log4j]]
	=== Example: Logging with Apache Log4j

	It is possible to have the Jetty Server logging configured so that Log4j controls the output of logging events produced by Jetty.
	This is accomplished by configuring Jetty for logging to http://logging.apache.org/log4j/[Apache Log4j] via http://slf4j.org/manual.html[Slf4j] and the http://slf4j.org/manual.html#swapping[Slf4j binding layer for Log4j].

	A convenient replacement `logging` module has been created to bootstrap your `${jetty.base}` directory for logging with log4j.

	[source, screen, subs="{sub-order}"]
	....
	[mybase]$ mkdir modules
	[mybase]$ cd modules

	[modules]$ curl -O https://raw.githubusercontent.com/jetty-project/logging-modules/master/log4j-1.2/logging.mod
	% Total % Received % Xferd Average Speed Time Time Time Current
	Dload Upload Total Spent Left Speed
	100 720 100 720 0 0 2188 0 --:--:-- --:--:-- --:--:-- 2188
	[modules]$ cd ..

	[mybase]$ java -jar /opt/jetty-dist/start.jar --add-to-start=logging
	INFO: logging initialised in ${jetty.base}/start.ini (appended)
	MKDIR: ${jetty.base}/logs
	DOWNLOAD: http://central.maven.org/maven2/org/slf4j/slf4j-api/1.6.6/slf4j-api-1.6.6.jar to lib/logging/slf4j-api-1.6.6.jar
	DOWNLOAD: http://central.maven.org/maven2/org/slf4j/slf4j-log4j12/1.6.6/slf4j-log4j12-1.6.6.jar to lib/logging/slf4j-log4j12-1.6.6.jar
	DOWNLOAD: http://central.maven.org/maven2/log4j/log4j/1.2.17/log4j-1.2.17.jar to lib/logging/log4j-1.2.17.jar
	DOWNLOAD: https://raw.githubusercontent.com/jetty-project/logging-modules/master/log4j-1.2/log4j.properties to resources/log4j.properties
	DOWNLOAD: https://raw.githubusercontent.com/jetty-project/logging-modules/master/log4j-1.2/jetty-logging.properties to resources/jetty-logging.properties
	INFO: resources initialised transitively
	INFO: resources enabled in ${jetty.base}/start.ini

	[mybase]$ java -jar /opt/jetty-dist/start.jar
	....

	The replacement `logging.mod` performs a number of tasks.

	. `mybase` is a `${jetty.base}` directory.
	. The jetty-distribution is unpacked (and untouched) into `/opt/jetty-dist/` and becomes the `${jetty.home}` directory for this demonstration.
	. The `curl` command downloads the replacement `logging.mod` and puts it into the `${jetty.base}/modules/` directory for use by mybase only.
	. The `start.jar --add-to-start=logging` command performs a number of steps to make the logging module available to the `${jetty.base}` configuration.
	.. The `--module=logging` command is added to the `${jetty.base}/start.ini` configuration.
	.. Required `${jetty.base}` directories are created: `${jetty.base}/logs` and `${jetty.base}/resources`
	.. Required libraries are downloaded (if not present already): slf4j-api, slf4j-log4j, and log4j itself.
	* The libraries are put in the `${jetty.base}/lib/logging/` directory.
	.. Required configuration files are downloaded (if not present already): `jetty-logging.properties`, and `log4j.properties`
	* The configuration files are placed in the `${jetty.base}/resources/` directory.

	At this point the Jetty `mybase` is configured so that the Jetty server itself will log using log4j, using the log4j configuration found in `mybase/resources/log4j.properties`.

	The server classpath can be verified by using the `start.jar --list-config` command.

	In essence, Jetty is now configured to emit its own logging events to slf4j, and slf4j itself is using the static log binder found in `slf4j-log4j12.jar`, making all Jetty + Slf4j + Log4j events emitted by the Jetty server go to Log4j for routing (to console, file, syslog, etc...).