Apache TomEE - Tomcat with a kick

Editor's Notes

• #2: [Quick introduction] http://openejb.apache.org/3.0/apache-tomee.html Welcome to Apache TomEE – Tomcat with a kick. In this presentation we will introduce and demonstrate Apache TomEE, and show how you can leverage all the additional features available in the JavaEE 6 platform, without having to move away from Tomcat. We have got time for questions at the end, but please do feel free to ask any questions as we go along, and we'll do our best to answer them.
• #6: So, what is Apache TomEE? In short, its a stack that's assembled and maintained by the Apache OpenEJB project. TomEE aims to provide a fully certified Java EE 6 Web profile stack based on Tomcat, allowing you to use Java EE features in your lightweight Tomcat applications. Although TomEE is assembled by the OpenEJB team, its based on a number of different Apache projects shown on the slide. You may be familiar with or using some of these projects already. Even if you're not using EJBs in your projects, Apache TomEE still provides a range of functionality you may find useful.
• #8: Obviously there are a number of different Java EE servers available today, and a number of open source offerings. How is TomEE different from other implementations? Well, we take a different approach to building the server – many implementations will use Tomcat to provide a servlet features, and will strip it down and embed it in their own server. TomEE does the opposite – OpenEJB and all the other components are embedded into Tomcat, and nothing is taken away. This offers a number of advantages: Firstly, TomEE is able to leverage all the functionality that Tomcat provides, such as JNDI and security. Secondly, TomEE is still lightweight – the zip is around 37MB, and does not have any additional memory requirements over Tomcat to run. Finally, the environment will be completely familiar to existing Tomcat users, meaning that your existing tooling should still work. For example, there isn't a TomEE Eclipse plugin or Netbeans plugin – the existing out-of-the-box plugins for Tomcat 7 also work with TomEE.
• #11: Although we're introducing Apache TomEE as a new bundle, it has actually been around for a while, first making an appearance in 2006, and was inspired by OpenEJB's embeddable nature. Previously it has been known as the “OpenEJB-Tomcat integration”, and was (and still is) available as a drop-in .war file for any version of Tomcat back to 5.5. In addition to the drop-in .war, TomEE is now available as a pre-built bundle which requires no installation or configuration. Also worth mentioning, Apache TomEE is actually the origin of the “EJBs in war files” that is new in the JavaEE 6 specification. David, our PMC chair, participates in the JCP that provides the EJB specification and has done since EJB 2.1.
• #13: I'll now demonstrate how easy it is to get started with Apache TomEE, using the pre-built bundle. [Demo] - Unzip - Explain folder structure: - bin – untouched, shell scripts have the usual options - conf – server.xml is the same, one extra listener. Can configure ports, hosts, engines, threadpools etc in here. Extra file openejb.xml – this is where most TomEE configuration happens – this is where global resources are defined. Tomcat-users.xml – we use Tomcat security. - logs – untouched – extra file openejb.log ends up in here, useful for troubleshooting (rarely, we hope!) - webapps – works the same way as it does for Tomcat. Drop your directories/wars in here! Also supports EAR files too. Set of Tomcat apps, plus two extras: Ejb-examples – sample application from OpenEJB repository. Simple example showing a few JavaEE features – not very functional, but useful for testing. OpenEJB – where the magic happens. Note extra lib directory, some jars can be swapped out. Provides a dashboard to test the setup and examine the JNDI tree.
• #16: Now that we have a TomEE server up and running, I'll show you one of the example applications from OpenEJB, and deploy that to TomEE. The example I'm going to show you is the Moviefun example, and this is available from the subversion repository here. The application itself is very simple – a database of movies, catalogued by title, director, genre and year, and each one having a rating out of ten. It demonstrates a number of Java EE features, such as SL EJB session bean with a no-interface view, persistence with JPA, dependency injection, webservices and JMS. [Code] - Show Movie POJO - SLSB - Annotated servlet - JSF controller [Demo] - Stop existing server - Create WTP server - Configure to use openejb war too - Deploy and start server in debug mode - Show interface, setup db, browse web app. - Show breakpoint
• #19: One thing that might have struck you during the demo, is that we unzipped TomEE, deployed and used a database-based web application, all without doing any configuration at all – not even specifying a database to use. TomEE will use some default resources specified in conf/openejb.xml, including HSQLDB as a default datasource, which is why we didn't need to configure a database for the moviefun example. This is great for development, but you might want to use a different database in production, for example, MySQL. To do this we just need to add the MySQL connector jar to the Tomcat/lib folder, and add a datasource resource for the persistence context. The file is very easy to edit, its an XML/properties format. The xml tags match the annotations you'd use for dependency inject (for example @Resource) and type matches the simple name of the object type. [Example] Show database configuration in text editor
• #20: Rather than providing its own security implementation, TomEE makes full use of the security features that are part of Tomcat. Any Catalina realm is supported or you can provide your own security module using the login.config file. For example, to add some simple security to the moviefun application, all we would need to do is: 1. Add some users to the tomcat-users.xml file 2. Add the necessary @DefineRoles and @RolesAllowed annotations on MoviesImpl 3. Add some security config to do HTTP Basic authentication to web.xml Webservice security is also looked after – username/password based security (HTTP basic, or WS-Security) uses the same Tomcat security. Certificate based security is also available. Samples are available to demonstrate this.
• #23: By default, persistence in TomEE is taken care of by Apache OpenJPA. TomEE will deploy any persistence.xml files automatically. As well session EJBs, persistence units can also be injected into servlets and managed beans as well. Other JPA providers can also be used in TomEE, hibernate is particularly popular.
• #25: TomEE provides transaction support. Even if you aren't using EJBs, simply inject an UserTransaction @Resource into your servlets or MangedBeans.
• #27: JMS support is provided by Apache ActiveMQ. Topics and queues can be configured in conf/openejb.xml. These resources will be injected into EJBs / Servlets etc, if you use the @Resource annotation. [Show EJB from moviefun again] JMS topics and queues can be accessed externally by connecting to port 61616. The moviefun example includes a notification application which subscribes to a JMS topic which is notified when a movie is deleted from the database. [Run the notifier] [Delete my least favourite movie ever, Zoolander, from the application. Notice the popup].
• #28: [2 minutes] Webservice support is provided using Apache CXF. Both POJO and EJB webservices are supported, and is simply a matter of adding the @WebService annotation. [Show EJB again, highlight annotation] The moviefun example includes 2 Perl scripts that connect to the application via the webservice. [Show code and demonstrate] Webservice security is supported, either by requiring HTTP authentication, or WS-Security headers. There are a number of webservice examples available in the OpenEJB svn repository.
• #29: EJBs deployed in TomEE can also be accessed remotely using an EJB client. One nice feature of this is that TomEE uses HTTP/HTTPS as the protocol, so your rich applications can connect directly to EJBs without needing other firewall ports to be opened up. There's some sample code to do this on the slide. As long as you include the openejb-client jar in your client application, nothing else is needed. If you need to secure your EJBs, you can pass a username and password in the InitialContext properties.
• #31: Finally – if you're into functional testing, I wanted to demonstrate a technique I have used. OpenEJB's embeddable nature makes it great for testing EJBs in a junit test. You can take this one step further and use Apache TomEE with the Maven T7MP plugin. This allows you to start a TomEE instance (well, Tomcat 7 with the OpenEJB war) for your test run. Combined with an in-memory database and something like Selenium or HtmlUnit, you can run your application completely embedded within your Maven build, allowing you to run your tests completely in isolation of your development environment. This technique can be useful in providing a consistent environment for tests, and not having to worry about different setups between developer machines. [Show POM] [Show integration test]
• #33: That's the end of the presentation, thanks for joining us, and we hope you have found it useful. We'll try and answer any questions now. Please feel to join us on the mailing lists if you have questions later on, or if you want to participate!
• #34: I previously mentioned that Apache TomEE is aiming to be a certified web profile implementation. Work on the certification process is underway. Unfortunately we can't say what the status of the work is at the moment, as its subject to a non-disclosure agreement. We do have an interesting setup to run the TCK tests against TomEE, using lots of instances on the Amazon EC2 cloud. Again, unfortunately, we can't show you the setup, which is a shame, as it allows us to run the necessary tests very quickly, giving us fast feedback.