2. Agenda
This session describes how
developers using Java™ Platform,
Enterprise Edition can create
composite applications using BPEL
with current Java EE tools and
application servers that support Java
Business Integration
3. Agenda
Why Services
Why Composite Applications
BPEL in the Mix
A Java EE Based Composite Application
Summary
4. Why Services?
SOA = an architectural principle for structuring
systems that
SOA emphasizes the de-coupling of system
components
New services are created from existing ones in a
synergistic fashion
Strong service definitions are critical
Services can be subsequently re-composed in
response to changing business requirements
5. What Are Services?
A function accessed using XML message
exchange
Message exchanges have well known
exchange patterns
Services are self-describing, usingmetadata
(WSDL)
6. What Does a Service Do?
Transform data
Route messages
Query databases
Orchestrate conversations
Apply business logic
Apply business policy
Handle business exceptions
Solicit approvals
…
7. How Is a Service Implemented?
• XSLT
• Enterprise JavaBeans™ (EJB™) technology
• BPEL
• SQL
• XQuery
• Routing table
• Business rules
• EDI transform
• …
8. Service Oriented Architecture
In April 2006 the Object Management Group's (OMG) SOA Special Interest Group adopted
the following definition for SOA
Service Oriented Architecture is an architectural style for a Community of providers
and consumers of services to achieve mutual value, that
– Allows participants in the communities to work together with minimal co-
dependence or technology dependence
– Specifies the contracts to which organizations, people and technologies must
adhere in order to participate in the community
– Provides for business value and business processes to be realized by the
community
– Allows for a variety of technologies to be used to facilitate interactions within the
community
9. Service Oriented Architecture
In March 2006 the OASIS group SOA Reference Model released its first
public review draft.
This defines the basic principles of SOA that apply at all levels of a service
architecture, from business vision through to technical and
infrastructure implementation
– Service Oriented Architecture; a paradigm for organizing and
utilizing distributed capabilities that may be under the control of
different ownership domains.
– It provides a uniform means to offer, discover, interact with and use
capabilities to produce desired effects consistent with measurable
preconditions and expectations
10. Principles of SOA
Services share a formal contract
Services are loosely coupled
Services abstract underlying logic
Services are composable
Services are reusable
Services are autonomous
Services are stateless
Services are discoverable
11. 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
– New business opportunities
Greater ROI
– Leverage existing IT asset
12. Composite Applications
Composite applications are...applications!
Comprised of heterogeneous parts
– Some existing parts
– Some new parts
Composite applications != SOA
Composite applications employ SOA principles
– Features exposed as Web services
– Standards-based interaction between services
– Described by standards-based artifacts
– Are themselves composable
16. Composite Applications—Summary
A composite application is a collection of existing and
independently developed applications and new business logic,
orchestrated together into a brand new solution of a business
problem that none alone can solve
Such an application looks to the user like a regular new
interactive application, yet in reality it may be only 10 percent
new and 90 percent an assembly of pre-existing components or
data;
The “glue” that brings a composite application together is
integration technology
17. WS-BPEL Works With WSDL
Web Services Business Process Execution Language
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
18. What is BPEL?
XML-based language used to specify business
processes based on Web Services
BPEL processes describe
– Long running, stateful, transactional, conversations
between two or more partner web services
BPEL is key to implementing SOA Big Rules
– Conversational
– Mostly Async
– XML Document-based
– Orchestrated
19. BPEL Is a Web Service
Sequencing Language
Process defines “conversation” flow chart
– Conversation consists of only WSDL-described
message exchanges
– BPEL provides and consumes WSDL defined
services
Process instance is a particular conversation
following the chart
– Execution systems can support multiple
concurrent conversations
20. BPEL “Fixes” WSDL
WSDL: unordered set of operations
– Operations are message exchanges
• Need rules for ordering
• Support for sequencing
• Support for concurrency
• Choreography with external entities
21. Orchestration vs. Choreography
Orchestration
– An executable business process describing a flow from the
perspective and under control of a single endpoint
(commonly: Workflow)
– BPEL handles Orchestration
Choreography (WSDL)
– The observable public exchange of messages, rules of
interaction and agreements between two or more business
process endpoints
– WSDL handles Choreography
23. Business Process Needs To...
Co-ordinate asynchronous
communication between
services
Correlate message
exchanges between parties
Implement parallel
processing of activities
Implement compensation
logic(Undo operations)
Manipulate/transform data
between partner interactions
Support for long running
business transactions and
activities
Handle exception handling
Need for universal data
model for message
exchange
26. BPEL: Basic Activities
<invoke>
To invoke a one-way or request/response operation on a
portType offered by a partner
<receive>
To do a blocking wait for a matching message to arrive
Can be the instantiator of the business process
<reply>
To send a message in reply to a message that was
received through a <receive>
The combination of a <receive> and a <reply> forms a
request-response operation on the WSDL portType for the
process
27. BPEL: Basic Activities
<assign>
– Can be used to update the values of variables with new data
<throw>
– Generates a fault from inside the business process
<wait>
– Allows you to wait for a given time period or until a certain time
has passed
<empty>
– Allows you to insert a "no-op" instruction into a business process
– This is useful for synchronization of concurrent activities, for
instance
28. BPEL: Structured Activities
• <sequence>
Perform activities in sequential order
• <flow>
Perform activities in parallel
• <switch>
Conditional choice of activities
• <scope>
Enclose multiple activities in a single scope
32. Why Do You Care on BPEL?
• In SOA-enabled environment, you are more likely to
build an application by orchestration various services
via BPEL
• You will probably use BPEL design tool to create a
BPEL document
• The BPEL document is then executed by BPEL
engine
– Highly likely in JBI enabled platform
46. Runtime: Java EE Platform
and Java Business Integration
Java Business Integration serves as messaging
infrastructure
Java EE web services interact through Java Business
Integration
Java Business Integration bindings allow remote consumers
and providers
Add other service technologies as Java Business
Integration components
Transparent to programmer using Java EE
technology
Reuse without re-coding
49. Web Service Orchestration
Author, design, deploy and test business processes
with the BPEL Designer
– Supports the BPEL 2.0 constructs
– Adds powerful methods for visual authoring
– Step through debugging support
– Built in testing capability for unit testing
BPEL Mapper for BPEL variable assignments
– Quickly generate XPath expressions
Deploy to the built in BPEL engine
– Running as a service engine in the JBI environment within
the provided Sun Java System Application Server
50. Summary
SOA enables flexible and agile enterprise application
architecture
Services can be created and used using a variety of
Java EE technologies
BPEL is a service orchestration language for
creating stateful composite applications
Services can be re-implemented using other
technologies as long as service interface is
preserved without changing consumers
Java Business Integration is the enabling
infrastructure