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How to Define a Module Dependency and Use log4j in an Application

  • Author:
  • Contributors: Sande Gilda, Pete Muir
  • Last Update: Nov 08, 2013
  • Level: Beginner
  • Technologies:JBoss Modules
  • Target Product:EAP

What is it?

This simple JSF 2.0 application shows how to use container defined modules to limit the size of the application package. It also shows how to use common versions of certain classes at runtime.

Applications must often depend on third-party libraries. By default, Java EE packages allow you to include dependencies in a deployable unit which can lead to uncontrolled growth of the deployable unit. This can be avoided by the use of container defined modules. A module is nothing more than a container managed binary dependency which is shared by all deployed applications. For more informatin on class loading and modules please refer to "About Modules and the New Modular Class Loading System used in JBoss EAP 6" in the Development Guide for JBoss Enterprise Application Platform.

This example is very simple. It declares dependency on the Apache Log4j module which allows it to use a custom logging framework. This is achieved with a simple addition to the xml file: src/main/webapp/WEB-INF/jboss-deployment-structure.xml. For more information about this file please refer to the the Development Guide for JBoss Enterprise Application Platform.

System requirements

The application this project produces is designed to be run on Red Hat JBoss Enterprise Application Platform 6.1 or later.

All you need to build this project is Java 6.0 (Java SDK 1.6) or later, Maven 3.0 or later.

Configure Maven

If you have not yet done so, you must Configure Maven before testing the quickstarts.

Start the JBoss Server

  1. Open a command line and navigate to the root of the JBoss server directory.
  2. The following shows the command line to start the server:

     For Linux:   JBOSS_HOME/bin/standalone.sh
     For Windows: JBOSS_HOME\bin\standalone.bat
    

Build and Deploy the Quickstart

NOTE: The following build command assumes you have configured your Maven user settings. If you have not, you must include Maven setting arguments on the command line. See Build and Deploy the Quickstarts for complete instructions and additional options.

  1. Make sure you have started the JBoss Server as described above.
  2. Open a command line and navigate to the root directory of this quickstart.
  3. Type this command to build and deploy the archive:

     mvn clean install jboss-as:deploy
    
  4. This will deploy target/jboss-log4j.war to the running instance of the server.

Access the application

The application will be running at the following URL: http://localhost:8080/jboss-log4j/.

Undeploy the Archive

  1. Make sure you have started the JBoss Server as described above.
  2. Open a command line and navigate to the root directory of this quickstart.
  3. When you are finished testing, type this command to undeploy the archive:

     mvn jboss-as:undeploy
    

Run the Quickstart in JBoss Developer Studio or Eclipse

You can also start the server and deploy the quickstarts from Eclipse using JBoss tools. For more information, see Use JBoss Developer Studio or Eclipse to Run the Quickstarts

Debug the Application

If you want to debug the source code or look at the Javadocs of any library in the project, run either of the following commands to pull them into your local repository. The IDE should then detect them.

    mvn dependency:sources
    mvn dependency:resolve -Dclassifier=javadoc

Recent Changelog

  • Nov 8, 2013(Sande Gilda):Bz1028448 Add spaces to end of metadata so it renders with a line break in HTML
  • Oct 8, 2013(Sande Gilda):BZ1011833 Add HTML versions of README files and fix deployment instructions
  • Oct 2, 2013(Sande Gilda):README add Product Versions metadata remove versions in text remove temp repo from settings.xml
  • Sep 24, 2013(Sande Gilda):Remove references to web profile
  • Sep 24, 2013(Sande Gilda):Remove references to JBoss AS 7 from the quickstarts
  • Sep 23, 2013(Sande Gilda):Update metadata source URLs to new repository
  • Sep 13, 2013(Sande Gilda):JDF 487 Remove as from quickstart artifactId and archive names and access URLs in README files
  • Jun 12, 2013(Sande Gilda):Modify README file internal links to use generated anchors. Remove hard coded anchors. Fixed obsolete links and other markdown rendering problems
  • Feb 12, 2013(Sande Gilda):Add quickstart source repository of record to the README files
  • Sep 11, 2012(Sande Gilda):Add target product https issues.jboss.org browse JDF 108
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