Assure Ecommerce and Retail Operations Uptime with ThousandEyes
Prakash Narayan Killer S O Aapps Using J2 E E
1. This Presentation Courtesy of the
International SOA Symposium
October 7-8, 2008 Amsterdam Arena
www.soasymposium.com
info@soasymposium.com
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2. SOA & Java EE:
Developing killer SOA
applications using the Java EE
Platform
Prakash Narayan
Sun Microsystems
3. Goal
Visualizing and developing composite
applications using BPEL, SOA and
Java EE
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5. Applications
• Developers need to build end-to-end applications
> Front-end user interfaces
> Middle-tier business logic
> Back-end resources
• With the right approach, developers can...
> Reuse existing parts
> Build new parts
> Glue old and new parts together
• With the wrong approach, developers must...
> Reimplement functionality existing elsewhere
> Spend massive effort to evolve applications
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6. Applications
• Real-world applications are...
> ...not Web applications
> ...not Java EE applications
> ...not Swing forms
> ...not Web services
> ...not BPEL processes
> ...not SOA
> ...not JBI
> ...not RDBMSs
> ...not (your favorite technology)
• Real-world applications use many or all of these
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7. Applications
• Traditional model of application development
> Point technologies, products, and APIs
> For example: EJB, Spring, Hibernate, JSF, Servlets, Struts, etc.
> Lots of glue written by developers
> Requires a great deal of expertise & time
> Inflexible
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8. Composite Applications
• A way to compose applications from reusable parts
• Comprised of heterogeneous parts
> Some existing parts
> Some new parts
> Some glue to connect these parts
• Composite applications are Applications!
> Composite applications != SOA
• Composite applications employ SOA principles
> Features exposed as Web services
> Standards-based interaction between services
> Are themselves composable 7
10. What Are Services?
• Black-box components with well-defined interfaces
> Performs some arbitrary function
> Can be implemented in myriad ways
• Accessed using XML message exchanges
> Using well-known message exchange patterns (MEPs)
• Services are self-describing
• Metadata in the form of WSDL describes...
> Abstract interfaces
> Concrete endpoints
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11. What Can Services Do?
• Perform business logic
• Transform data
• Route messages
• Query databases
• Apply business policy
• Handle business exceptions
• Prepare information for use by a user interface
• Orchestrate conversations between multiple services
• …
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12. How Are Services Implemented?
• Enterprise JavaBeans™ (EJB™) technology
• BPEL
• XSLT
• SQL
• Business rules
• Mainframe transaction
• EDI transform
• Humans (yes, really!)
• …
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15. Purchase Service Functions
WS WS
DL/
Buyer DL/
Supplier
Soa
Endpointp Soa
Endpointp
Buyer
BPE Supplier
BP E
L
Conversation L
Conversation
E JB
Transaction Fees
Rout
ing T
Supplier Routing
abl
e
XQ
Supplier
uer
y
Selection XSL
Product
T
Conversion
R
Buyerule
Credit
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16. Service Oriented Architecture (SOA)
• An architectural principle for structuring systems
into coarse-grained services
• Technology-neutral best practice
• Emphasizes the loose coupling of services
• New services are created from existing ones
in a synergistic fashion
• Strong service definitions are critical
• Services can be re-composed when business
requirements change
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17. Benefits of SOA
• Flexible (Agile) IT
> Adaptable to changing business needs
• Faster time to market
> Reuse existing code
> Minimize new development
• Business- and process-driven
> Enables new business opportunities
• Greater ROI
> Leverage existing IT assets
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19. Java EE 5 Overview
• Key development features
> EJB 3.0
> Annotated “plain old Java object” (POJO) Web services
> Powerful Java Persistence API (JPA) for O-R mapping
> JAX-WS 2.1 and JAXB 2.1
> Samples and blueprints
• Open ESB Starter Kit
> Java Business Integration (JBI) runtime
> BPEL service engine
> SOAP-over-HTTP binding component
• GlassFish V2
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20. Java EE Services
• Use EJB 3.0 to develop standards-based worker
services
> Perform business logic
> Access JDBC resources
> Call other Web services, including BPEL processes
> Transactional
> Secure
• JAX-WS 2.1 and JAXB 2.1
> Full support for XML Schema
> Document-centric services
• Call these services from BPEL processes
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21. EJB 3.0 Example
@Stateless()
@WebService()
public class LoanProcessor {
@WebMethod
public String processApplication(...,
@WebParam(name="applicantAge") int applicantAge,...) {
int MINIMUM_AGE_LIMIT = 18; int MAXIMUM_AGE_LIMIT = 65;
String result = "Loan Application APPROVED."
if (applicantAge < MINIMUM_AGE_LIMIT) {
result = "Loan Application REJECTED - Reason:
Under-aged "+applicantAge+". Age needs to be "+
over"+MINIMUM_AGE_LIMIT+" years to qualify.";
return result;
}
...
}
} 20
23. Need for Business Process
• Developing the web services and exposing the
functionality (via WSDL) is not sufficient
• Example:
> Concert ticket purchase Web service has 3 operations,
which need to be performed in the following order
> Getting a price quote
> Purchase a ticket
> Confirmation and cancellation
• We also need a way to orchestrate these functionality
> Sequencing
> Conditional action
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24. Business Processes
• Any technology for implementing real-world
business processes needs to...
> Coordinate asynchronous communication between
services
> Correlate message exchanges between partners
> Exchange messages in a universal form
> Process activities in parallel
> Manipulate/transform data between partners
> Support long-running business transactions
> Handle exceptions
> Provide compensation to undo previous actions
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25. What is BPEL?
• BPEL = Business Process Execution Language
> XML-based language used to specify business
processes based on Web services
> Orchestrates partner Web services
• BPEL processes describe...
> Long-running, stateful, transactional conversations
• BPEL is one language for implementing a service
> A BPEL service is itself a WSDL-described service
> Can be used from other services or BPEL processes like
any other Web service
• BPEL processes are easy to write and change
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26. What is BPEL?
• Cannot “do” much without other services
> Orchestrates other WSDL-described Web services
> Can't access non-Web service components
> Other partner services do the real work
> These are called functional services or worker services
• Excels at...
> Parallelism
> Long-running conversations
> Sending and receiving Web service messages
> Complex decision logic
> Fault handling and compensating logic
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27. BPEL: Relationship to Partners
WSDL
Partner Service
Partner Service
Partner Service
Orchestrating Process
(BPEL) Partner Service
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28. BPEL: Relationship to Partners
WSDL Inventory
Checker Service
Credit checker
Service
Customer
Service
Orchestrating Process Another Partner
(BPEL) Service
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29. Example Business Process
Receive <PO> <sequence>
Invoke <InventoryService> Invoke <CreditService> <flow>
Reply <Invoice> </sequence>
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31. BPEL Works With WSDL
• Web services are described in WSDL
> Operations are message exchanges
> Each operation represents an individual unit of action
• We need a way to orchestrate these operations with
multiple web services in the right order to perform a
Business process
> Sequencing, conditional behavior etc.
• BPEL provides standard-based orchestration of
these operations
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32. BPEL “Fixes” WSDL
• WSDL describes an unordered set of operations
> Operations are grouped as interfaces
> Operations are individual message exchanges
• Semantics of the interface are missing in WSDL
> Order of invocation
> Concurrency
> Choreography with external entities
• BPEL can supply these missing semantics
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34. NetBeans IDE 6.1
● Support for composite applications in NetBeans 6.1
● Design BPEL business processes to orchestrate:
● Java EE Web services
● External Web services
● Other BPEL processes
● Develop secure, identity-enabled Java EE Web
services
● Visualize, analyze, and edit real-world XML
Schema, WSDL, and XML instance documents
● Download: http://www.netbeans.org
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35. Web Service Orchestration
● Visually author BPEL 2.0 business processes with
the BPEL Designer
● Step-through debugging support
● Built-in testing capability for unit testing
● “Beyond syntax” validation of Schema, WSDL, and BPEL
● BPEL Mapper
● Visually create complex XPath expressions without coding
● Deploy to the built-in BPEL engine
● JBI-based BPEL service engine + SOAP/HTTP bindings
● Running within the bundled GlassFish V2 Server
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37. BPEL Module Project
• BPEL Module project is a group of source files
which includes
> XML Schema (*.xsd) files
> WSDL files
> BPEL files
• Within a BPEL Module project, you can author a
business process compliant with the WS-BPEL 2.0
language specification.
• Will be added to a Composite application as a JBI
module
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38. Composite Application Project
• Composite Application project is a project whose
primary purpose is to assemble a deployment unit
for the Java Business Integration (JBI) server
> BPEL Module projects must be added to a Composite
Application project in order to be deployed to the BPEL
runtime.
• The Composite Application Project can also be
used to create and execute test cases that can then
be run, in JUnit fashion, against the deployed BPEL
processes.
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39. Composite Application Project
• With a Composite Application project, you can:
> Assemble an application that uses multiple project types
(BPEL, XSLT, IEP, SQL, etc.)
> Configure external/edge access protocols (SOAP, JMS,
SMTP, and others)
> Build JBI deployment packages
> Deploy the application image to the target JBI server
> Monitor the status of JBI server components and
applications
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41. Summary
• SOA enables flexible and agile enterprise
application architecture
• Services can be created and used using Java EE
• BPEL is a service orchestration language
for creating composite applications
• Services can be re-implemented using other
technologies as long as service interfaces
are preserved without changing consumers
• Java Business Integration (JBI) is the enabling
infrastructure
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43. Call to Action!
• Download NetBeans IDE 6.1 :
http://download.netbeans.org/netbeans/6.1/final/
• Join Sun Developer Network (SDN) for up-to-date
SOA information:
http://developers.sun.com
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