BPEL Example Ja

Overview of the ServiceMix 1.x BPEL Example

This document describes how to run ServiceMix's BPEL example and provides details about what it does. For information on the business use case, please refer to: Use Case for BPEL.

The BPEL example illustrates the following:

• an example of declarative programming
• how to perform BPEL integration with ServiceMix

The XML code for the BPEL example is located in the ServiceMix installation directory under the examples\bpel directory in the servicemix.xml file. It is recommended that you refer to the servicemix.xml file while reading this document.

This example will start a component which sends a SOAP message to a JmsServiceComponent which forwards the request to the PXE BPEL engine and waits for a response. A simple JMS client is provided so that messages can sent and received from the JMSService. This example uses PXE integration to demonstrate the use of BPEL with ServiceMix.

Prerequisites to Run the BPEL Example

The following must be installed to run this example:

• Java Standard Edition 5.0
• Ant - http://ant.apache.org.
• PXE - We support WS-BPEL via the PXE BPEL Engine from FiveSight.

Running the BPEL Example

First, run ServiceMix with a JNDI context configured so that PXE can be deployed.

PXE has a JBI component and deployment unit which can be auto-deployed in any JBI compliant container. To use PXE with ServiceMix put the PXE deployment unit into the install directory in the BPEL example directory and the component will be auto-deployed in ServiceMix. This has already been done - look in the install directory under the servicemix_install_dir\examples\bpel directory to see PXE jar file.

From a command shell, go to the BPEL example directory:

cd [servicemix_install_dir]\examples\bpel

where servicemix_install_dir is the directory in which ServiceMix was installed.

Then type:

[servicemix_install_dir]\bin\servicemix servicemix.xml

OR

..\..\bin\servicemix servicemix.xml

You should now have PXE deployed with a JBI service engine together with a deployment unit for a specific BPEL process.

Send the business process messages to trigger it. Compile and run a simple JMS client. The client is built and run from source using Ant. Execute 'ant from BPEL's directory, servicemix_install_dir\examples\bpel to run the JMS client:

ant

Ant will compile and run the simple JMS client which performs a JMS based request-response into the ServiceMix container before returning the results to the console.

Stopping the BPEL Example

To terminate the BPEL example type "CTRL-C" in the command shell in which it is running and answer "y" to the "Terminate batch job (y/n)?" question.

How it Works

The diagram below illustrates the logical flow of the program through the BPEL components.

The logical flow of the program is:

1. The JMSClient through ActiveMQConnectionFactory connects to topic "demo.org.servicemix.source" and sends a text message from message.soap file.
2. myComponent being a subscriber of topic "demo.org.servicemix.source", receives the message.
3. myComponent implementation class JmsServiceComponent sends the message over the ServiceMix bus to the PxeBpelEngine by executing its onMessage method. The destinationService property defines the destination of the message (destinationService is found in the servicemix.xml file.
4. PxeBpelEngine sends a response again through SericeMix bus, the NMR.
5. myComponent uses the jmsTemplate bean to publish the message.
6. jmsTemplate uses the jmsFactory bean to get a connection to the port associated with the JMS topic called "demo.org.servicemix.source." The message is published on the "demo.org.servicemix.source" topic.
7. JMSClient being a subscriber of topic "demo.org.servicemix.source", receives the message.

Logginginformation is written to the console as files are transmitted. Typical output looks like the following:

 
 
ServiceMix ESB: 1.0.1

Loading ServiceMix from file: servicemix.xml
[INFO] XmlBeanDefinitionReader - -Loading XML bean definitions from file [C:\Program Files\servicemix-1.0.1\examples\file-binding\servicemi.xml]
[INFO] FileSystemXmlApplicationContext - -Bean factory for application context [org.springframework.context.support.FileSystemXmlApplication
Context;hashCode=7486844]: org.springframework.beans.factory.support.DefaultListableBeanFactory defining beans [workManager,jbi]; root of BeanFactory hierarchy
[INFO] FileSystemXmlApplicationContext - -2 beans defined in application context 
[org.springframework.context.support.FileSystemXmlApplicationContext;hashCode=7486844]
[INFO] CollectionFactory - -JDK 1.4+ collections available
[INFO] CollectionFactory - -Commons Collections 3.x available
[INFO] FileSystemXmlApplicationContext - -Unable to locate MessageSource with name 'messageSource': using default [org.springframework.conte
xt.support.DelegatingMessageSource@1d6776d]
[INFO] FileSystemXmlApplicationContext - -Unable to locate ApplicationEventMulticaster with name 'applicationEventMulticaster': using defaul
t [org.springframework.context.event.SimpleApplicationEventMulticaster@4fce71]
[INFO] DefaultListableBeanFactory - -Pre-instantiating singletons in factory [org.springframework.beans.factory.support.DefaultListableBeanF
actory defining beans [workManager,jbi]; root of BeanFactory hierarchy]
[INFO] DefaultListableBeanFactory - -Creating shared instance of singleton bean 'workManager'
[INFO] DefaultListableBeanFactory - -Creating shared instance of singleton bean 'jbi'
Created MBeanServer with ID: 203c31:106bd250a5b:-7fff:Lisas:1
[INFO] SpringInitialContextFactory - -Loading JNDI context from: class path resource [jndi.xml]
[INFO] XmlBeanDefinitionReader - -Loading XML bean definitions from class path resource [jndi.xml]
[INFO] XmlBeanFactory - -Creating shared instance of singleton bean 'jndi'
RMIConnectorServer started at: service:jmx:rmi://lisas/jndi/rmi://localhost:1099/defaultJBIJMX
[INFO] JBIContainer - -ServiceMix JBI Container (http://servicemix.org/) name: defaultJBI running version: ServiceMix.
[INFO] JBIContainer - -Activating component for: [container=defaultJBI,name=fileSender,id=fileSender] with service: fileSender component: org.servicemix.components.file.FileWriter@b1cc87
[INFO] ComponentContextImpl - -Component: fileSender activated endpoint: fileSender : fileSender
[INFO] JBIContainer - -Activating component for: [container=defaultJBI,name=filePoller,id=filePoller] with service: filePoller component: or
g.servicemix.components.file.FilePoller@183e7de
[INFO] ComponentContextImpl - -Component: filePoller activated endpoint: filePoller : filePoller
[INFO] DeliveryChannel - -default destination serviceName for filePoller = fileSender

Note: In the servicemix.xml file, the "destinationService" attribute of the filePoller component is "foo:fileSender." The last line of output (above) shows the NMR using that to deliver the normalized message to fileSender.

Details

The following table provides more details about the function of each component and bean in the servicemix.xml file.

Summarizing, when the ServiceMix container instantiates an MBean it firsts sets the property values if there are any, then calls the init() method of the class and its' parent classes, if applicable. Then it calls the start() method of the class. When a Spring bean starts up, the properties are set and then the afterPropertiesSet() method is called.

Related Documentation

For more information on the following topics please see:

• NMR

• Spring