{section}{column}
( this is a first draft )

h1. Features

This Service-Engine (SE) allows to expose Talend jobs as services into Petals and to execute them inside the bus.
This component supports jobs created with both Talend Open Studio and Talend Integration Suite. It also provides several mechanisms to pass information and data to a job.

Before going further, it must be clear that no configuration for this component is intended to be created by hand.
And neither by the Petals Studio. In fact, only Talend Open Studio and Talend Integration Suite have the ability to generate a correct configuration for this component.
However, which one of these tool created the configuration is not important for this service-engine.

Before installing the bc-ejb component, you must check in your $\{PETALS_HOME}/conf/server.properties configuration file if the property "petals.classloaders.isolated=true" is set and uncommented. The BC-EJB component need the isolated classloaders to work correctly.

The component can be configured through its JBI descriptor file like this :
{code:lang=xml}<?xml version="1.0" encoding="UTF-8"?>
<jbi:jbi xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:petalsCDK="http://petals.ow2.org/components/extensions/version-4.0"
xmlns:jbi="http://java.sun.com/xml/ns/jbi" version="1.0">

<jbi:component type="binding-component" component-class-loader-delegation="parent-first">

<jbi:identification>
<jbi:name>petals-bc-ejb</jbi:name>
<jbi:description>an EJB Binding Component sending messages to local or distant EJB instances</jbi:description>
</jbi:identification>

<jbi:component-class-name>org.ow2.petals.bc.ejb.EjbBC</jbi:component-class-name>
<jbi:component-class-path>
<jbi:path-element/>
</jbi:component-class-path>
<jbi:bootstrap-class-name>org.ow2.petals.component.framework.DefaultBootstrap</jbi:bootstrap-classname>
<jbi:bootstrap-class-path>
<jbi:path-element/>
</jbi:bootstrap-class-path>

<petalsCDK:acceptor-pool-size>5</petalsCDK:acceptor-pool-size>
<petalsCDK:processor-pool-size>10</petalsCDK:processor-pool-size>
<petalsCDK:ignored-status>NOTHING_IGNORED</petalsCDK:ignored-status>
<shared-library>petals-sl-ejb</shared-library>
<petalsCDK:jbi-listener-class-name>org.ow2.petals.bc.ejb.listener.JBIListener</petalsCDK:jbi-listener-class-name>
</jbi:component>
</jbi:jbi>{code}


This component doesn't have any specific configuration parameters.&nbsp;

You can customize the component configuration by changing the following common parameters.
{include:0 CDK Component Configuration Table}
{warning}
EJB binding component can only handle outgoing message (JBI \-> EJB), so you can't specify an external-listenerclass-name.{warning}

h1. Service Configuration


h2. Send a JBI message to an external EJB

When a JBI message is received on an endpoint linked to an EJB, the message is transformed into a RMI message, then&nbsp;sent to the linked EJB.


!petals-bc-ejb.png!


The RMI message is created following these steps :
# The JBI message payload is mapped to Java objects. These objects (and their types) are used as operation parameters&nbsp;for the RMI call. The mapping is done thanks to the PEtALS-JAXB-Databinding library. For more information about&nbsp;XML databinding feel free to read the chapter entitled XML to Java binding.
# The JBI message exchange operation local part is used as the EJB method to invoke.
# If a security subject is provided by the JBI message it is used as authentication information during the RMI invokation.

In order to reach the remote EJB, the component need to get an RMI stub of the EJB from a JNDI server. The JNDI name of the target EJB is defined in the parameter ejb.jndi.name.

The external EJB is called and the response is processed by the PEtALS-JAXB-Databinding library and then returned&nbsp;to the JBI environment.

h2. Service Unit descriptor

The Service Unit descriptor file ( jbi.xml ) looks like this :
{code:lang=xml}<?xml version="1.0" encoding="UTF-8"?>

<!--
JBI descriptor for the PEtALS' "petals-bc-ejb" component (EJB).
Originally created for the version 1.1 of the component.
-->

<jbi:jbi version="1.0"
xmlns:ejb="http://petals.ow2.org/components/ejb/version-1.1"
xmlns:generatedNs="http://application.localisation.watersupply.petals.ow2.org/"
xmlns:jbi="http://java.sun.com/xml/ns/jbi"
xmlns:petalsCDK="http://petals.ow2.org/components/extensions/version-4.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

<!-- Import a Service into PEtALS or Expose a PEtALS Service => use a BC. -->
<jbi:services binding-component="true">

<!-- Import a Service into PEtALS => provides a Service. -->
<jbi:provides
interface-name="generatedNs:LocalisationFinderBusinessServicePortType"
service-name="generatedNs:LocalisationFinderBusinessService"
endpoint-name="LocalisationFinderBusinessServiceEndpoint">

<!-- CDK specific elements -->
<petalsCDK:wsdl>Localisation.wsdl</petalsCDK:wsdl>

<!-- Component specific elements -->
<ejb:ejb.jndi.name>LocalisationFinderBusinessService</ejb:ejb.jndi.name>
<ejb:java.naming.factory.initial>org.jnp.interfaces.NamingContextFactory</ejb:java.naming.factory.initial>
<ejb:java.naming.provider.url>jnp://localhost:1099/</ejb:java.naming.provider.url>
<ejb:ejb.version>2.1</ejb:ejb.version>
<ejb:ejb.home.interface>org.ow2.petals.watersupply.localisation.application.LocalisationFinderBusinessServiceRemoteHome</ejb:ejb.home.interface>
<ejb:marshalling.engine>jaxb</ejb:marshalling.engine>
<ejb:security.name />
<ejb:security.principal />
<ejb:security.credencials />

</jbi:provides>
</jbi:services>
</jbi:jbi>
{code}

| security.credencials | Password | \- | No |
| marshalling.engine | The marshalling engine to use | jaxb | Yes |
{table-plus}

{include:0 CDK SU Provide Configuration}
{include:0 CDK Interceptor configuration for SU}

h2. Service Unit content&nbsp;


The service unit must contain a JAR archive including the EJB Interface (and EJB Home Interface for a 2.x EJB) and all specific Java classes used by this interface.

It is also highly recommended to provide a WSDL description of your EJB interface. This WSDL description will be used as Service Description for the JBI Endpoint linked to your EJB.

The directory structure of a SU for the BC-EJB must look like this :

{noformat}my-su-ejb.zip
+ META-INF
- jbi.xml
- my-ejb-wsdl-description.wsdl
- my-ejb.jar
- my-ejb-dependency1.jar
- my-ejb-dependency2.jar


h2. Provider restrictions


h2. Provider usage{noformat}

h1.