Once i was thinking about writing Enterprise Java Beans(EJBs) with the Scala programming language. This should be easy as Scala greatly incorporates with existing Java code bases. But let’s create a small test to verify this!
For this example, i am using Apache TomEE 1.5.1 as a JEE Web Profile certified server and Scala 2.10 to create a small stateless session bean and invoke it from a servlet. The stateless bean is injected to the servlet using CDI. I use IntelliJ 12 as my favorite IDE.
Here is the Scala code for the stateless session bean:
package de.mirkosertic.scala
import javax.ejb.Stateless
import util.Random
@Stateless
class StatelessBean {
val random = Random
def sayHello() = "Hello " + random.nextInt
}I use the JEE @Stateless annotation to mark the Scala class as a stateless session bean. The bean has a public sayHello() method, which just returns the string “Hello ” concatenated with a random number. Here is the JEE servlet which uses the JEE bean:
package de.mirkosertic.java;
import de.mirkosertic.scala.StatelessBean;
import javax.ejb.EJB;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
@WebServlet("/servlet")
public class TestServlet extends HttpServlet {
@EJB
StatelessBean statelessBean;
@Override
protected void doGet(HttpServletRequest aRequest, HttpServletResponse aResponse) throws ServletException, IOException {
PrintWriter theWriter = aResponse.getWriter();
theWriter.print("<html><body>");
theWriter.print(statelessBean.sayHello());
theWriter.print("</body></html>");
}
}After compiling it and invoking it from the browser, we see a “Hello” text with a random number. It is working! We can create Enterprise Java Beans with Scala, so we have Enterprise Scala Beans :-)
Git revision: 63a36b0