User suexec asked ##java about accessing an EJB from a JSP template.
User dreamreal (i.e., your author) put together a simple application (rather imaginatively called “suexec-war” ) to explore the possibilities. The application was built from Adam Bien‘s minimalistic Java EE 7 Maven archetype, deployed into Wildfly 10.0.
It turns out that to the best of my understanding, injection of an EJB into a JSP is simply unsupported. The JSP can use JNDI to acquire an EJB via JNDI (see source) but the CDI injection never worked.
Next, I wrote a simple servlet (called, of all things, TestServlet.java). Here, the @EJB MyEJB ejb worked like a charm.
To render, I used the Handlebars template library just for kicks; Freemarker (or even JSP itself) would have worked just as well, but I wanted to play with something different.
The process would have been the same no matter what templating library was chosen: you’d take the values you wanted to render and store them somewhere such that the rendering engine could access them. In my case, I could have built a composite object (or even asked Handlebars to call the greet() method itself, using the ejb value) but I was aiming for simplicity rather than optimal behavior, following whaley’s “Make it work, make it pretty, make it fast” principle (from “Suffering-oriented programming” )- this is rough code, meant to serve more as a smoke test than an actual example of a great application, so I left off at “make it work,” leaving even “make it pretty” to others.
Comments and improvements welcomed.
Tag: java ee 7
Interesting Links, 5 Feb 2016
- “O Java EE 7 Application Servers, Where Art Thou?” is a humorously-titled summary of the state of Java EE 7 deployment options, covering the full and web profiles for Java EE 7. It’s the sort of thing one wants to know, honestly: great job, Antonio.
- From Stack Overflow, “How to get started with Akka streams?” is a Scala question, not a Java one, but Akka has a Java implementation as well. The first answer (accepted, upvoted) is a fantastic explanation. I may port it to pure Java just for example’s sake…
- From our friends at DZone, Orson Charts 1.5 is Open Source announces that Orson Charts 1.5 has been released, and it’s available under the GPLv3 (a commercial license is available for people who don’t want the restrictions of the GPL). It’s a 3D charting library, not a 2D charting library, and they say if you need 2D charts, you should use JFreeChart – Orson Charts looks great on first impressions, though. (It’s worth noting that apparently both Orson Charts and JFreeChart were from the same author.)
- More from DZone: Application Security for Java Developers is a summary of security concerns. It’s really more of a short “have you thought of this?” post – useful, but not very deep.