Getting Started with Simple wso2 ESB EJB Mediator Sample

The EJB mediator calls an external Enterprise JavaBean(EJB) and stores the result in the message payload or in a message context property. Currently, this mediator supports EJB3 Stateless Session Beans and Stateful Session Beans.

Before Start first look what is EJB Mediator and what is EJB now Let's see how to Run a Simple Hello Name using EJB Mediator. in order to run the the sample we need to configure our Environment So the Requirements are

• WSO2 ESB
• JBoss
• HelloName Demo

In the context of EJB the the implementation is focused on statefull and stateless session beans, so later when dicussing the sample scenarios and will dig in to the details on how to configure those with the WSO2 Ejb mediator

So let us now focus now on configuring EJB service invocation with WSO2 ESB.

Configure the ESB

• Please download Jboss 7(jboss-as-7.1.1.Final Latest)  we do have test this with different application servers but for this demonstration we will be using Jboss 7 there you need to  copy jboss-client.jar to ESB_HOME/repository/components/lib
• Please find the HelloName.jar (Ejb service) you will be find the HelloName  jar attached with this article (will discuss what this demo service and its implementation separately) please copy the HelloName.jar file to  JBOSS_HOME/standalone/deployments/  and  ESB_HOME/repository/components/lib
• As next step you may have to configure AS connection properties and the you will be able define them in  synapse.properties (ESB_HOME/repository/conf ) it has following properties which is required to communicate with the AS,depending on the application server which you may use the configuration parameteres might get change, the following is required when you need to connect EJB services hosted in Jboss AS 7
• Start ESB and Jboss AS

Configure Ejb Mediator for stateless bean

Idea of this demo such as when requests closest location he has to pass the name and  in this scenario when the requests comes first we need to invoke the sayHello method which is exposed as EJB service, and to invoke the method it requires to check HelloWorld so it we picking the name and pass it to ejb Container and the return result will be assign to the synapse property context  and using enrich mediator we can transform the incoming request as requires by the source, let see how this can be configured in ESB level

ejb Proxy

<?xml version="1.0" encoding="UTF-8"?>
<proxy xmlns="http://ws.apache.org/ns/synapse"
       name="ejb"
       transports="https,http"
       statistics="disable"
       trace="disable"
       startOnLoad="true">
   <target>
      <inSequence>
         <property name="response" value="init" scope="default" type="STRING"/>
         <log level="custom">
            <property name="response" value="{//name}"/>
         </log>
         <ejb beanstalk="jack"
              class="org.NewBeanRemote"
              method="sayHello"
              target="response"
              jndiName="ejb:/EJBModule3/NewBean!org.NewBeanRemote">
            <args>
               <arg xmlns:m="http://org" value="{//m:name}"/>
            </args>
         </ejb>
         <payloadFactory media-type="xml">
            <format>
               <ejb xmlns="">
                  <response>$ctx.response</response>
               </ejb>
            </format>
            <args/>
         </payloadFactory>
         <respond/>
      </inSequence>
   </target>
   <description/>
</proxy>

in above proxy we need to set beanstalk , class, method, target and  jndiName we already looked about these parameters in previous post about EJB Mediator. here my beanstalk id is jack bu we can set unique id for that the important thing is we are going to use this name in synapse properties to set the property values. my class name is org.NewBeanRemote and method name is sayHello . the value which my method returning is naming as response in target finally we can catch the jndi name from JBoss server console.

synapse property

synapse.beanstalks=jack
synapse.beanstalks.jack.java.naming.factory.url.pkgs=org.jboss.ejb.client.naming
synapse.beanstalks.jack.cache.warn.limit.stateless=5
synapse.beanstalks.jack.cache.warn.limit.stateful=5
synapse.beanstalks.jack.cache.timeout.stateless=1
synapse.beanstalks.jack.cache.timeout.stateful=1

after  set the synapse properties value we will sent the below request to the proxy which we create as ejb.

Soap Request

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
  <soapenv:Body>
    <sayHello xmlns="http://org">
<name>rajjaz</name>
    </sayHello>
  </soapenv:Body>
</soapenv:Envelope>  

 if everything success you will get bellow response to your soap Request

Soap Response

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
   <soapenv:Body>
      <ejb>
         <response>Hello rajjaz</response>
      </ejb>
   </soapenv:Body>
</soapenv:Envelope>

Debug Log

[2015-10-09 10:39:09,699] DEBUG - wire >> "POST /services/ejb.ejbHttpSoap11Endpoint HTTP/1.1[\r][\n]"
[2015-10-09 10:39:09,700] DEBUG - wire >> "Accept-Encoding: gzip,deflate[\r][\n]"
[2015-10-09 10:39:09,700] DEBUG - wire >> "Content-Type: text/xml;charset=UTF-8[\r][\n]"
[2015-10-09 10:39:09,700] DEBUG - wire >> "SOAPAction: "urn:mediate"[\r][\n]"
[2015-10-09 10:39:09,701] DEBUG - wire >> "Content-Length: 201[\r][\n]"
[2015-10-09 10:39:09,701] DEBUG - wire >> "Host: rajjaz-ThinkPad-T540p:8280[\r][\n]"
[2015-10-09 10:39:09,701] DEBUG - wire >> "Connection: Keep-Alive[\r][\n]"
[2015-10-09 10:39:09,702] DEBUG - wire >> "User-Agent: Apache-HttpClient/4.1.1 (java 1.5)[\r][\n]"
[2015-10-09 10:39:09,702] DEBUG - wire >> "[\r][\n]"
[2015-10-09 10:39:09,702] DEBUG - wire >> "<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">[\n]"
[2015-10-09 10:39:09,702] DEBUG - wire >> "  <soapenv:Body>[\n]"
[2015-10-09 10:39:09,702] DEBUG - wire >> "    <sayHello xmlns="http://org">[\n]"
[2015-10-09 10:39:09,702] DEBUG - wire >> "<name>rajjaz</name>[\n]"
[2015-10-09 10:39:09,702] DEBUG - wire >> "    </sayHello>[\n]"
[2015-10-09 10:39:09,702] DEBUG - wire >> "  </soapenv:Body>[\n]"
[2015-10-09 10:39:09,703] DEBUG - wire >> "</soapenv:Envelope>"
[2015-10-09 10:39:09,707] DEBUG - ProxyServiceMessageReceiver Proxy Service ejb received a new message from : 127.0.0.1
[2015-10-09 10:39:09,708] DEBUG - ProxyServiceMessageReceiver Message To: /services/ejb.ejbHttpSoap11Endpoint
[2015-10-09 10:39:09,708] DEBUG - ProxyServiceMessageReceiver SOAPAction: urn:mediate
[2015-10-09 10:39:09,708] DEBUG - ProxyServiceMessageReceiver WSA-Action: urn:mediate
[2015-10-09 10:39:09,708] DEBUG - ProxyService Setting default fault-sequence for proxy
[2015-10-09 10:39:09,708] DEBUG - ProxyServiceMessageReceiver Using the anonymous in-sequence of the proxy service for mediation
[2015-10-09 10:39:09,708] DEBUG - SequenceMediator Start : Sequence <anonymous>
[2015-10-09 10:39:09,708] DEBUG - SequenceMediator Sequence <SequenceMediator> :: mediate()
[2015-10-09 10:39:09,708] DEBUG - SequenceMediator Mediation started from mediator position : 0
[2015-10-09 10:39:09,708] DEBUG - SequenceMediator Building message. Sequence <SequenceMediator> is content aware
[2015-10-09 10:39:09,709] DEBUG - PropertyMediator Start : Property mediator
[2015-10-09 10:39:09,709] DEBUG - PropertyMediator Setting property : response at scope : default to : init (i.e. constant : init)
[2015-10-09 10:39:09,709] DEBUG - PropertyMediator End : Property mediator
[2015-10-09 10:39:09,709] DEBUG - LogMediator Start : Log mediator
[2015-10-09 10:39:09,709]  INFO - LogMediator response = {//name}
[2015-10-09 10:39:09,710] DEBUG - LogMediator End : Log mediator
[2015-10-09 10:39:09,933] DEBUG - PayloadFactoryMediator #mediate. Transformed payload format>>> <pfPadding><ejb><response>Hello rajjaz</response></ejb></pfPadding>
[2015-10-09 10:39:09,933] DEBUG - RespondMediator Start : Respond Mediator
[2015-10-09 10:39:09,940] DEBUG - RespondMediator End : Respond Mediator
[2015-10-09 10:39:09,940] DEBUG - SequenceMediator End : Sequence <anonymous>
[2015-10-09 10:39:09,941] DEBUG - wire << "HTTP/1.1 200 OK[\r][\n]"
[2015-10-09 10:39:09,941] DEBUG - wire << "Host: rajjaz-ThinkPad-T540p:8280[\r][\n]"
[2015-10-09 10:39:09,941] DEBUG - wire << "SOAPAction: "urn:mediate"[\r][\n]"
[2015-10-09 10:39:09,941] DEBUG - wire << "Accept-Encoding: gzip,deflate[\r][\n]"
[2015-10-09 10:39:09,941] DEBUG - wire << "Content-Type: text/xml;charset=UTF-8; charset=UTF-8[\r][\n]"
[2015-10-09 10:39:09,941] DEBUG - wire << "Date: Fri, 09 Oct 2015 05:09:09 GMT[\r][\n]"
[2015-10-09 10:39:09,941] DEBUG - wire << "Transfer-Encoding: chunked[\r][\n]"
[2015-10-09 10:39:09,941] DEBUG - wire << "Connection: Keep-Alive[\r][\n]"
[2015-10-09 10:39:09,941] DEBUG - wire << "[\r][\n]"
[2015-10-09 10:39:09,941] DEBUG - wire << "ce[\r][\n]"
[2015-10-09 10:39:09,941] DEBUG - wire << "<?xml version='1.0' encoding='UTF-8'?><soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"><soapenv:Body><ejb><response>Hello rajjaz</response></ejb></soapenv:Body></soapenv:Envelope>[\r][\n]"
[2015-10-09 10:39:09,941] DEBUG - wire << "0[\r][\n]"
[2015-10-09 10:39:09,941] DEBUG - wire << "[\r][\n]"

Source

References

• http://www.dushantech.com/2012/06/syntaxhighlighter.html
• http://docs.wso2.com/display/ESB490/EJB+Mediator

WSO2 ESB EJB Mediator

The EJB mediator calls an external Enterprise JavaBean(EJB) and stores the result in the message payload or in a message context property. Currently, this mediator supports EJB3 Stateless Session Beans and Stateful Session Beans.

 

 

 

 Syntax

<ejb beanstalk="string" class="string" [sessionId="string"] [remove="true | false"] 
  [method="string"] [target="string | {xpath}"] [jndiName="string"] /> 
    <args> 
      <arg (value="string | {xpath}")/>* 
    </args> 
</ejb>

This is how EJB Mediator will be in proxy

Parameter Name	Description
Add Argument	Can be used to define the arguments which is required for the particular ejb method to be invoked Expression/Value.
Beanstalk ID	Reference to the application server specific connection source information, which is defined at the synapse.properties.
Class	This required the remote interface definition provided in the EJB 3.0 (EJB service invocation remote/home interface).
JNDI Name	The Java Naming and Directory Interface (JNDI) is an application programming interface (API) for accessing different kinds of naming and directory services. JNDI is not specific to a particular naming or directory service. It can be used to access many different kinds of systems including file systems; distributed objects systems such as CORBA, Java RMI, and EJB; and directory services such as LDAP, Novell NetWare, and NIS+.
Remove	This parameter specifies whether the Enterprise Entity Manager should remove the EJB context related parameters once the state full/stateless session is invoked.
Session ID	When the EJB context is invoked in the form state-full bean then the related ejb session status specified will be stored in here. Possible values are as follows. Value: If this is selected, the session ID can be entered as a static value. Expression: If this is selected, an XPath expression can be entered to evaluate the session ID.
Target	If a particular EJB method returns, then the return object can be saved against the the name provided in the target at the synapse property context.

 

Sample ejb Syntax

    <ejb beanstalk="rajjaz"
              class="org.NewBeanRemote"
              method="sayHello"
              target="response"
              jndiName="ejb:/EJBModule3/NewBean!org.NewBeanRemote">
            <args>
               <arg xmlns:m="http://org" value="{//m:name}"/>
            </args>
         </ejb>

above one is the sample catch the value come as name and pass it to the method sayHello in ejb class JNDI Named as NewBeanRemote then it will catch the output come within response tag.

the values for the JNDI Properties will be set the Synapse.properties

Synapse.properties

synapse.beanstalks=rajjaz
synapse.beanstalks.rajjaz.java.naming.factory.url.pkgs=org.jboss.ejb.client.naming
synapse.beanstalks.rajjaz.cache.warn.limit.stateless=5
synapse.beanstalks.rajjaz.cache.warn.limit.stateful=5
synapse.beanstalks.rajjaz.cache.timeout.stateless=1
synapse.beanstalks.rajjaz.cache.timeout.stateful=1  

lets discuss how to run helloworld sample using WSO2 ESB ejb mediator in next post

Source code

References

• https://docs.wso2.com/display/ESB490/EJB+Mediator#EJBMediator-Example

Getting Started with Simple Remote EJB 3.X Server Sample

This sample will give you a simple working experience with EJB client server . here I’m using netbeans as IDE and JBoss 5.1 as my EJB Container. and I created seperate client for Stateful an Stateless EJB sessions  in order to make easy the development .We'll create a ejb module project named EJBTestServer.

1. In NetBeans IDE, select ,File > New Project Select project type under category,Java EE, Project type as Ejb Module. Click Next > button. Enter project name as EJBTestServer and location. Click Next > button.

 

Select Server as JBoss Application Server. Click Finish button.

above step will give the simple skeleton for the ejb project. our next step is to add the beans to ejb so lets create a Session Bean.

Create a sample EJB

To create a simple EJB, we'll use NetBeans "New" wizard. In example below, We'll create a stateless ejb class named NewSessionBean under EJBTestServer  project. Select project EJBTestServer in project explorer window and right click on it. Select, New > Session Bean.

Enter session bean name and package name. Click Finish button. You'll see the following ejb classes created by NetBeans.

• NewSessionBean - stateless session bean
• NewSessionBeanLocal - local interface for session bean

I am changing local interface to remote interface as we're going to access our ejb in a console based application. Remote/Local interface are used to expose business methods that an ejb has to implement.

NewSessionBeanLocal is renamed to NewSessionBeanRemote and NewSessionBean implements NewSessionBeanRemote interface.

 NewSessionBeanRemote.java

package org1;

import javax.ejb.Remote;

/**
 *
 * @author rajjaz
 */
@Remote
public interface NewSessionBeanRemote {
    public String display();
    public String sayHello(String name);
}

NewSessionBean.java

package org1;

import javax.ejb.Stateless;

/**
 *
 * @author rajjaz
 */
@Stateless
public class NewSessionBean implements NewSessionBeanRemote {

    // Add business logic below. (Right-click in editor and choose
    // "Insert Code > Add Business Method")
        public String display(){
        return "Hello JBoss";
    }
    public String sayHello(String name){
        this.count++;
        return "Hello " + name;
    }
}

Do the above way to create the bean for the Stateful Session also

• NewStatefulSessionBean - stateful session bean
• NewStatefulSessionBeanRemote - local interface for session bean

 NewStatefulSessionBeanRemote.java

package org1;

import javax.ejb.Remote;

/**
 *
 * @author rajjaz
 */
@Remote
public interface NewStatefulSessionBeanRemote {
        void increment();

    void decrement();

    int getCount();
}

NewStatefulSessionBean.java

package org1;

import javax.ejb.Remote;
import javax.ejb.Stateful;

/**
 *
 * @author rajjaz
 */
@Stateful
@Remote(NewStatefulSessionBeanRemote.class)
public class NewStatefulSessionBean implements NewStatefulSessionBeanRemote {

    // Add business logic below. (Right-click in editor and choose
    // "Insert Code > Add Business Method")
    
    
    private int count = 0;

    @Override
    public void increment() {
        this.count++;
    }

    @Override
    public void decrement() {
        this.count--;
    }

    @Override
    public int getCount() {
        return this.count;
    }
}

Now Right Click on project and click on Clean and Build then you will get the below output

ant -f /home/rajjaz/NetBeansProjects/EJBTestServer -Dnb.internal.action.name=rebuild clean dist
init:
undeploy-clean:
deps-clean:
Deleting directory /home/rajjaz/NetBeansProjects/EJBTestServer/build
Deleting directory /home/rajjaz/NetBeansProjects/EJBTestServer/dist
clean:
init:
deps-jar:
Created dir: /home/rajjaz/NetBeansProjects/EJBTestServer/build/classes
Copying 2 files to /home/rajjaz/NetBeansProjects/EJBTestServer/build/classes/META-INF
Created dir: /home/rajjaz/NetBeansProjects/EJBTestServer/build/empty
Compiling 4 source files to /home/rajjaz/NetBeansProjects/EJBTestServer/build/classes
compile:
library-inclusion-in-archive:
Created dir: /home/rajjaz/NetBeansProjects/EJBTestServer/dist
Building jar: /home/rajjaz/NetBeansProjects/EJBTestServer/dist/EJBTestServer.jar
dist:
BUILD SUCCESSFUL (total time: 0 seconds)

next to that deply the project. if project was successfully deployed you will get the below output

14:33:30,677 INFO  [EJBContainer] STARTED EJB: org1.NewSessionBean ejbName: NewSessionBean
14:33:30,680 INFO  [JndiSessionRegistrarBase] Binding the following Entries in Global JNDI:

 NewSessionBean/remote - EJB3.x Default Remote Business Interface
 NewSessionBean/remote-org1.NewSessionBeanRemote - EJB3.x Remote Business Interface

14:33:30,693 INFO  [SessionSpecContainer] Starting jboss.j2ee:jar=EJBTestServer.jar,name=NewStatefulSessionBean,service=EJB3
14:33:30,693 INFO  [EJBContainer] STARTED EJB: org1.NewStatefulSessionBean ejbName: NewStatefulSessionBean
14:33:30,697 INFO  [JndiSessionRegistrarBase] Binding the following Entries in Global JNDI:

 NewStatefulSessionBean/remote - EJB3.x Default Remote Business Interface
 NewStatefulSessionBean/remote-org1.NewStatefulSessionBeanRemote - EJB3.x Remote Business Interface

14:33:38,933 WARN  [InterceptorsFactory] EJBTHREE-1246: Do not use InterceptorsFactory with a ManagedObjectAdvisor, InterceptorRegistry should be used via the bean container
14:33:38,933 WARN  [InterceptorsFactory] EJBTHREE-1246: Do not use InterceptorsFactory with a ManagedObjectAdvisor, InterceptorRegistry should be used via the bean container

That's all now our project was successfully deployed on Jboss Server our next step step is create simple client to test this server

Server Source Code

Create a simple Client