These are frameworks for different layers. JSF is for the view (web) layer, it’s a component oriented framework (every part of a page is a component, it has state) like Wicket or Tapestry, and unlike Action frameworks like Spring MVC, Struts or Stripes Books: Core JavaServer Faces (3rd Edition) Tutorials: CoreServlets.com EJB 3.x is a … Read more
A JavaBean is just a plain old Java object that conforms to certain conventions including the use of accessor functions (getFoo/setFoo) for member access, provision of a default constructor and a few other things like that. An Enterprise JavaBean is a component in a Java EE application server which comes in several flavours, the details … Read more
First of all, Spring and EJB(+JTA) are competing technologies and usually not to be used together in the same application. Choose the one or the other. Spring or EJB(+JTA). I won’t tell you which to choose, I will only tell you a bit of history and the facts so that you can easier make the … Read more
Check out EJB 3.1 @Asynchronous methods. This is exactly what they are for. Small example that uses OpenEJB 4.0.0-SNAPSHOTs. Here we have a @Singleton bean with one method marked @Asynchronous. Every time that method is invoked by anyone, in this case your JSF managed bean, it will immediately return regardless of how long the method … Read more
They were most likely looking for examples of web frameworks – for example, JSF is a component-based framework, and Struts is a request-based framework. Request-based frameworks generally make it clear through their APIs that they’re working with parsing an HTML request / generating an HTML response, while Component-based frameworks attempt to abstract this away and … Read more
First of all, “J2EE” is an obsolete abbreviation, it is now simply called “Java Enterprise Edition” or Java EE. Contrary to the servlet container (e.g. Tomcat), “full” Java EE application servers contain also an EJB container. EJB are Enterprise Java Beans and you can read a lot about them for example here (chapter IV). EJBs … Read more
EJBs are built on top of RMI. Both imply Java clients and beans. If your clients need to be written in something else (e.g., .NET, PHP, etc.) go with web services or something else that speaks a platform-agnostic wire protocol, like HTTP or XML over HTTP or SOAP. If you choose RMI, you don’t need … Read more
I am not sure this is supposed to work. So either: Option 1: Use the injection provider SPI Implement a provider that will do the lookup and inject the EJB. See: @EJB injection. Example for com.sun.jersey:jersey-server:1.17 : import com.sun.jersey.core.spi.component.ComponentContext; import com.sun.jersey.core.spi.component.ComponentScope; import com.sun.jersey.spi.inject.Injectable; import com.sun.jersey.spi.inject.InjectableProvider; import javax.ejb.EJB; import javax.naming.Context; import javax.naming.InitialContext; import javax.ws.rs.ext.Provider; import java.lang.reflect.Type; … Read more
The rules are (from memory): Bean has a @LocalBean annotation -> bean has a no-interface view Bean has a @Local annotation -> bean has a local view Bean has a @Remote annotation -> bean has a remote view Bean has no view annotations, but directly implements an interface which has a @Local annotation -> bean … Read more
Remote client view When your EJB and its clients will be in a distributed environment – meaning EJBs and clients will reside on separate Java virtual machines. Example : EJBs hosted on a WebSphere Application Server and Servlets that consume EJB APIs hosted on a Tomcat server. Local client view Only when it is guaranteed … Read more