= New in OpenEJB 3.0
:index-group: EJB
:jbake-date: 2018-12-05
:jbake-type: page
:jbake-status: published

== EJB 3.0

OpenEJB 3.0 supports the EJB 3.0 specification as well as the prior EJB
2.1, EJB 2.0, and EJB 1.1. New features in EJB 3.0 include:

* Annotations instead of xml
* No home interfaces
* Business Interfaces
* Dependency Injection
* Intercpetors
* Java Persistence API
* Service Locator (ala SessionContext.lookup)
* POJO-style beans

EJB 2.x features since OpenEJB 1.0 also include: - MessageDriven Beans -
Container-Managed Persistence (CMP) 2.0 - Timers

The two aspects of EJB that OpenEJB does not yet support are: - Web
Services (JAX-WS, JAX-RPC) - CORBA

JAX-WS and CORBA support will be added in future releases. Support for
the JAX-RPC API is not a planned feature.

= Extensions to EJB 3.0

== CMP via JPA

Our CMP implementation is a thin layer over the new Java Persistence API
(JPA). This means when you deploy an old style CMP 1.1 or CMP 2.1 bean
it is internally converted and ran as a JPA bean. This makes it possible
to use both CMP and JPA in the same application without any coherence
issues that can come from using two competing persistence technologies
against the same data. Everything is ultimately JPA in the end.

== Extended Dependency Injection

Dependency Injection in EJB 3.0 via `@Resource` is largely limited to
objects provided by the container, such as DataSources, JMS Topics and
Queues. It is possible for you to supply your own configuration
information for injection, but standard rules allow for only data of
type String, Character, Boolean, Integer, Short, Long, Double, Float and
Byte. If you needed a URL, for example, you'd have to have it injected
as a String then convert it yourself to a URL. This is just plain silly
as the conversion of Strings to other basic data types has existed in
JavaBeans long before Enterprise JavaBeans existed.

OpenEJB 3.0 supports injection of any data type for which you can supply
a JavaBeans PropertyEditor. We include several built-in PropertyEditors
already such as Date, InetAddress, Class, File, URL, URI, Map, List and
more.

[source,java]
----
import java.net.URI;
import java.io.File;
import java.util.Date;

@Stateful 
public class MyBean {
    @Resource URI blog;
    @Resource Date birthday;
    @Resource File homeDirectory;
}
----

== The META-INF/env-entries.properties

Along the lines of injection, one of the last remaining things in EJB 3
that people need an ejb-jar.xml file for is to supply the value of
env-entries. Env Entries are the source of data for all user supplied
data injected into your bean; the afore mentioned String, Boolean,
Integer, etc. This is a very big burden as each env-entry is going to
cost you 5 lines of xml and the complication of having to figure out how
to add you bean declaration in xml as an override of an existing bean
and not accidentally as a new bean. All this can be very painful when
all you want is to supply the value of a few `@Resource` String fields in
you bean class.

To fix this, OpenEJB supports the idea of a
META-INF/env-entries.properties file where we will look for the value of
things that need injection that are not container controlled resources
(i.e. datasources and things of that nature). You can configure you ejbs
via a properties file and skip the need for an ejb-jar.xml and it's 5
lines per property madness.

[source,properties]
----
blog = http://acme.org/myblog
birthday = locale=en_US style=MEDIUM Mar 1, 1954
homeDirectory = /home/esmith/
----

== Support for GlassFish descriptors

Unit testing EJBs with OpenEJB is a major feature and draw for people,
even for people who may still use other app servers for final deployment
such as Geronimo or GlassFish. The descriptor format for Geronimo is
natively understood by OpenEJB as OpenEJB is the EJB Container provider
for Geronimo. However, OpenEJB also supports the GlassFish descriptors
so people using GlassFish as their final server can still use OpenEJB
for testing EJBs via plain JUnit tests in their build and only have one
set of vendor descriptors to maintain.

== JavaEE 5 EAR and Application Client support

JavaEE 5 EARs and Application Clients can be deployed in addition to ejb
jars. EAR support is limited to ejbs, application clients, and
libraries; WAR files and RAR files will be ignored. Per the JavaEE 5
spec, the META-INF/application.xml and META-INF/application-client.xml
files are optional.

== Application Validation for EJB 3.0

Incorrect usage of various new aspects of EJB 3.0 are checked for and
reported during the deployment process preventing strange errors and
failures.

As usual validation failures (non-compliant issues with your
application) are printed out in complier-style "all-at-once" output
allowing you to see and fix all your issues in one go. For example, if
you have 10 `@PersistenceContext` annotations that reference an invalid
persistence unit, you get all 10 errors on the _first_ deploy rather
than one failure on the first deploy with 9 more failed deployments to
go.

Validation output comes in three levels. The most verbose level will
tell you in detail what you did wrong, what the options are, and what to
do next... even including valid code and annotation usage tailored to
your app that you can copy and paste into your application. Very ideal
for beginners and people using OpenEJB in a classroom setting.

== Most configurable JNDI names ever

= General Improvements

== Online Deployment ## Security Service ## Connection Pooling ##
Configuration Overriding ## Flexible JNDI Name Formatting ## Cleaner
Embedding ## Tomcat 6 Support ## Business locals remotable

If you want to make business local interfaces remotable, you can set
this property:

[source,properties]
----
  openejb.remotable.businessLocals=true
----

Then you can lookup your business local interfaces from remote clients.

You'd still have to ensure that the you pass back and forth is
serializable.