Post on 07-Apr-2015
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Using State-Engine as an SCA Spring component in SOA Suite 11g
OOW 2010
Guido Schmutz,Technology Manager / Partner Trivadis AG
23.09.2010, San Francisco
© 2009SOA Suite 11g Spring Component / Apache Commons SCXML
Introduction
Guido Schmutz Working for Trivadis for more than 13 years
leading and independent IT service company operating in Germany, Austria and Switzerland
Oracle ACE Director for Fusion Middleware and SOA Co-Author of different books Consultant, Trainer Software Architect for Java,
Oracle, SOA and EDA
More than 20 years of software development experience
Contact: guido.schmutz@trivadis.com Blog: http://guidoschmutz.wordpress.com/
© 2009
About Trivadis
3
Swiss IT consulting company
13 locations in Switzerland, Germany and Austria
~ 540 employees
Key figures 2008
Services for more than 650 clients in over 1‘600 projects
Over 150 service level agreements
More than 5‘000 training participants
Research and development budget:
CHF 6.0 Mio. / EUR 3.6 Mio.
© 2009
Idea for this session
Test what you can really to with the Spring Component A bit more than just another HelloWorld sample Test Drive it with a more complex use case
Integrate an existing implemementation (Apache Commons SCXML library) into SOA Suite as an Spring Component By that show that a state engine offers another (sometimes better?)
approach for documenting (business) processes
Just a Proof of Concept for myself !!
Have a „sexy“ presentation topic for OOW 2010 ;-)
SOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
Result
Not successfull !
Issues with the classloader when trying to initiate the Commons SCXML (ClassNotFoundException)!
I‘m talking to the Oracle Development to see how to solve that!SOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
Summary
There can be issues with the classloader
Make sure that you test what you want to integrate right upfront
So this is it !???
Of course not, just changed my topic slightly and I will present some interesting use cases with the Spring Component in SOA Suite 11g and in a 2nd part the Apache Commons SCXML library!
SOA Suite 11g Spring Component / Apache Commons SCXML
Lessons learnt: Do not create sexy and fancy abstracts just to get accepted to OOW ;-) Or make sure before that it‘s somehowachievable....
Basel · Baden · Bern · Lausanne · Zürich · Düsseldorf · Frankfurt/M. · Freiburg i. Br. · Hamburg · München · Stuttgart · Wien
SOA Suite 11g Spring Component /Apache Commons SCXML
OOW 2010
Guido Schmutz,Technology Manager / Oracle ACE Director
Partner Trivadis AG
23.09.2010, San Francisco
© 2009
Agenda
Data are always part of the game.
Spring Component of SOA Suite 11g Introduction Hello World “Advanced” Use Cases
State Machine and Apache Commons SCXML What are State Machines What is Apache Commons SCXML
SOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
SOA Suite 11gR1 PS2 Architecture
9
Oracle Restricted and Confidential
Unified Runtime
BPMNBPMN
Policy ManagerOptimized
binding
Human Workflow
(+AMX, AG, Orgn)
Human Workflow
(+AMX, AG, Orgn)
Business Rules
Business Rules
Oracle Service Bus
Common JCA-based connectivity infrastructure
RepositoryRepository
EM console+BPMN Screens
BAM
B2B
MediatorMediator
Workspace Process Portal(WC spaces)
MS Office
Create and Submit Order
ProcessPayment
NotifyUser
DownloadVideo
Wait3 days
Call Customer
Customer
Customer
Sales Rep
Copy toS3
Create and Submit Order
ProcessPayment
NotifyUser
DownloadVideo
Wait3 days
Call Customer
Customer
Customer
Sales Rep
Copy toS3
BPM Studio(with Business and IT views)
Shared BPMN Model
Business View
BPA
BPMN 2.0, BPEL
Rich End User InteractionWeb based customization
Process Composer
BPELBPEL
ProcessAnalytics
Proc Cubes
SpringSpring
© 2009
The Spring component
„Officially“ introduced with SOA Suite 11g PS2
Allows to publish Java Interfaces implemented by Spring beans as a service that can be used inside a composite application
By that part of the logic required in a SOA composite can be easily
implemented in Java an used like any other service component a Spring Ban can be reused within the composite and even outside the
composite either as an EJB or as a Web Service
Additionally the Java beans in the Spring Context component can call services exposed by other Service components and Adapter bindings Java bean can retrieve records from a database table using the DB
adapterSOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
Agenda
Data are always part of the game.
Spring Component of SOA Suite 11g Introduction Hello World “Advanced” Use Cases
State Machine and Apache Commons SCXML What are State Machines What is Apache Commons SCXML
SOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
The HelloWorldImpl POJO used inside a Spring component
Hello World – Step 1
SOA Suite 11g Spring Component / Apache Commons SCXML
Lessons learnt: Make sure to compile classes before wiring!
© 2009
Hello World – Step 2
Add the GreetingProvider strategy interface to provide an extended greeting message
SOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
Hello World – Step 3
Implement the GreetingProvider as a separate Spring component and wire it to the HelloWorld component
© 2009
Hello World – Step 4
Implement the GreetingProvider as a Mediator component and wire it to the HelloWorld component
Lessons learnt: if you delete a wire, the <sca:reference> elementis also removed
© 2009
<sca:service> Element
Declares a Spring bean that SCA exposes as a service
Takes the following attributes Name
the name of the service (required) Type
The fully qualified Java type of the Java class to be exposed as an SCA service (required)
Target The bean to be exposed as a service (required)
SOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
<sca:reference> Element
Declares a Spring bean representing an SCA service external to the Spring application context
Takes the follwing attributes Name
The name of the reference (required) Type
The fully-qualified Java type of the interface or class representing the remote service (required)
Default The target bean for the reference if none is specified (optional)
SOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
Callback
the concept of callbacks does not exist in the spring framework
For Oracle SOA Suite a callback is specified as a 2nd port type for interface.wsdl or a 2nd Java name for interface.java
The spring metadata has only sca:services and sca:references and no way to specify a callback
To design a callback with spring, you must provide sca:services and sca:references with a specific name create a sca:service and sca:reference using naming conventions of
someService and someServiceCallback Oracle SOA Suite recognizes this convention and creates a callback
SOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
Agenda
Data are always part of the game.
Spring Component of SOA Suite 11g Introduction Hello World “Advanced” Use Cases
State Machine and Apache Commons SCXML What are State Machines What is Apache Commons SCXML
SOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
Use Case 1: Accessing the Spring Context
Use Case: Want to access/lookup another bean from the spring context
Idea: Implement the Lifecycle Interface
SOA Suite 11g Spring Component / Apache Commons SCXML
Lessons learnt: Only a BeanFactory and not an ApplicationContextis created!
© 2009
Use Case 2: Groovy Script
Use Case: Want to use the Spring Dynamic Language Support to execute a Groovy Script
Idea: use the <lang:groovy> tag and reference the script and put the external libraries in SCA-INF/lib of the SOA project
SOA Suite 11g Spring Component / Apache Commons SCXML
Lessons learnt: Classloader is not my friend!
© 2009
Use Case 3: Executing Task asynchronously
Use Case: Want to execute a possible long running Java method asynchronously
Idea: use the Spring TaskExecutor abstraction
SOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
Use Case 4: Schedule a Job
Use Case: Want to Schedule a job/task/service to run repeatedly
Idea: use a Timer to schedule the call of a „service references“
SOA Suite 11g Spring Component / Apache Commons SCXML
Lessons learnt: „free-floating“ Spring bean (timerFactory) is not initialized! it need to referenced from a bean which is externalized as a service!
© 2009
Use Case 5: Schedule Job torun delayed
Use Case: Want to schedule a method/service to run delayed
Idea: use a Timer and schedule the call of a „service references“ through a service call
SOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
Use Case 6: Caching
Use Case: Want to cache some information and access it in a next request
Idea: use a Map and store the information in there
Could be further extended by using Oracle Coherence to get access to the Grid !
SOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
Summary
Spring Component is a very nice and long awaited feature!
Uses cases for it are endless….. Just presented some use cases to whet your appetite!
Only use the Spring Component if there is no out-of-the-box feature offered by SOA Suite itself
Make sure that your external library works before you invest too much time!
Actual books where you’llfind more informationabout SOA Suite:
SOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
Agenda
Data are always part of the game.
Spring Component of SOA Suite 11g Introduction Hello World “Advanced” Use Cases
State Machine and Apache Commons SCXML What is a State Machine What is Apache Commons SCXML
SOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
Indroduction
A state describes the condition of an object at a given point in its lifetime
"A state is a condition or situation during the life of an object during which it satisfies some condition, performs some activity, or waits for some event"
[Booch et al. (1999) UML Language User Guide, p291]
A state diagram describes all possible states of an object & the paths to get from one state to another when an external event is received
SOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
What is a state machine ?
A state machine diagram models the behaviour of a single object/system
specifies the sequence of events that an object/system goes through during its lifetime in response to events
SOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
Building Blocks
Start and End States
State Actions
Transitions
Self Transitions
SOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
Building Blocks
Compound States History State
SOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
Building Blocks
Concurrent Blocks
SOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
Agenda
Data are always part of the game.
Spring Component of SOA Suite 11g Introduction Hello World “Advanced” Use Cases
State Machine and Apache Commons SCXML What is a State Machine What is Apache Commons SCXML
SOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
What is State Chart XML (SCXML)
Generic and environment agnostic markup language for state machine definition W3C Working Draft (13 May 2010) http://www.w3.org/TR/scxml/
Based on UML 2.0 and Harel State transition tables
SOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
SCXML features
States and transitions Composite, Orthogonal and Final Events, guards and targets
Data Model Pluggable data representation and expression language
Executable content On entry, exit or transition Extensible
External communications module Send, cancel Invoke, Finalize
HistorySOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
Apache Commons SCXML
http://commons.apache.org/scxml/
Implements State Chart XML (SCXML)
The only Java engine which implements SCXML (as far as I know)
The "standard actions" defined by the SCXML specification are <var>, <assign>, <log>, <send>, <cancel>, <if>, <elseif>,
<else>. SOA Suite 11g Spring Component / Apache Commons SCXML
© 2009
State Actions
SOA Suite 11g Spring Component / Apache Commons SCXML
stm state-action
first
+ entry / log entering+ exit / log exiting
next
Final
Initial
to.next
© 2009
Transitions (simple, condition, self)
SOA Suite 11g Spring Component / Apache Commons SCXML
stm transitions
main
processing
Initial
Final
to.processing[counter >= 4]
fi le.received[counter < 4]
© 2009
Parallel States
SOA Suite 11g Spring Component / Apache Commons SCXML
stm parallel
parallel
[para-1]
[para-2]
para11
Initial
para12
para21 para22
Synch
to.para12
to.para22
© 2009
Timeout with Custom Action
SCXML can be extended with custom action Used for timeout transitions
SOA Suite 11g Spring Component / Apache Commons SCXML
stm timeout
start-state expired
next
Initial
to.next
timeout[after2sec]
to.start
© 2009
Send action
<send> can used to send events and data to external systems, including external SCXML Interpreters, or to raise events in the current SCXML session
SOA Suite 11g Spring Component / Apache Commons SCXML
stm send-internal
main
+ entry / signal event "to.processing"
processing Error
Initial
Final
to.processing error.send.targetunavailable
© 2009
Using SCXML in a SOA
Implemented a Spring Wrapper around Commons SCXML
Exposed a Web Service interface through Spring-WS
Created Publisher compontents to publish/signal events via Event Delivery Network (EDN) or Web Services
SOA Suite 11g Spring Component / Apache Commons SCXML
cmp SOA-State-Engine
l istenerStateEnginecreateInstance
triggerEvent
listener
send
EDNPublisher
signal
WebServ icePublisher
signal
Basel · Baden · Bern · Lausanne · Zürich · Düsseldorf · Frankfurt/M. · Freiburg i. Br. · Hamburg · München · Stuttgart · Wien
Thank you!
ODTUG 2010
Guido Schmutz,Technology Manager / Partner Trivadis AG
29.6.2010, Washington