Spring and SOA (2006)

Spring and SOA

Merelbeke, 7/11/2006

Agenda What is SOA

JAXB2, Spring WS en XFire

JBI and the ESB

ServiceMix

About SOASERVICE ORIENTED ARCHITECTURE

What is “Service Oriented Architecture”?

"Things should be made as simple as possible, but no simpler." -- Albert Einstein

Applications build on Loosely Coupled Services◦ Distributed resources◦ Made available as independent services◦ Services that are interoperable ◦ Interoperability based on contracts

Separation of Concerns

Elements of SOA

Stages of SOA

Fundamental SOA Only basic services

◦ Data-centric: exposes resources◦ Logic-centric: encapsulate business rules

Resources are never shared between services

Better Maintainability

Networked SOA Introduce intermediate services

◦ Techonology Gateways◦ Adapters◦ Façades (?)◦ Decorating services

Easier integration into Application frontends

More Flexibility

Process-Enabled SOA Introduce process-centric service(s)

◦ Statefull intermediate service◦ Hides process state from application frontend◦ Process state can be shared for multiple users◦ Can be event driven

Application frontend concentrates on User Interface (GUI or B2B)

Full Separation of Concerns

Implementing basic Services

Implementing Services Traditional Web Services: RPC

◦ Remote Procedure Call

SOA Web Services: contract first◦ First define the messages, then implement the code◦ Maximum interoperability

JAXB 2: Java Architecture for XML Binding

Java 6 standard extension for Java/XML Binding SchemaGen: generate xsd/wsdl from java pojo’s

◦ Customisable with javax.xml.bind annotations◦ javax.jws @WebService/ @WebMethod annotations

XJC: generate java from xsd/wsdl◦ Generate pojo’s with javax.xml.bind/javax.jws annotations◦ Customisable with xsd annotations or binding files◦ Plugin API for e.g. naming conventions or generating EJB3

annotations ◦ Ant task, maven plugin, eclipse plugin

Code example

Implementing services with XFire and Spring

Codehaus XFire: next generation java SOAP◦ Support for newest standards:

◦ JAXB 2.0: annotation based XML binding◦ JSR-181/JAX-WS 2.0: annotations for WSDL generation

◦ POJO based◦ Integration with Spring-core and Spring-MVC

Code example

Implementing services with Spring-WS

Document-driven web services◦ Can use XML directly as SAX, DOM, StAX…

◦ For efficiency, flexibility

◦ Can plugin Castor/JAXB/JiBX Marshallers

Similar architecture as Spring-MVC◦ Configurable Dispatcher◦ Endpoints as Controllers◦ Mappings/Filters/Interceptors…

Code example

JBI and the ESBJAVA BUSINESS INTEGRATION

About JBI Standards based API for Service Bus in a SOA

Normalized Message Router API

Container API for deploying Service Engines and Binding Components◦ Service Engine

◦ Business logic service◦ Transformation service◦ Integration of multiple services

◦ Binding Component◦ Connectivity to external services◦ Consumer or provider

JBI Message interfaces NormalizedMessage

◦ content: XML◦ attachments: name -> Mime content◦ properties: name -> object◦ security subject: authentication subject

MessageExchange: W3C Message exchange patterns◦ messages: name -> normalized message◦ exchange id: GUID◦ endpoint: service endpoint◦ service, interface name, operation: QName◦ subinterfaces: InOnly, InOptionalOut, InOut, RobustInOnly◦ status: ACTIVE, DONE, ERROR

JBI Component interfaces

Component◦ Lifecycle interface for service units

ServiceEndpoint◦ Addres of a service◦ List of interfaces◦ List of operations

ComponentContext◦ Callbacks for service units◦ Get delivery channel: accept/send MessageExchange◦ Get other ServiceEndpoints

ServiceMix JBI ContainerAN AGILE ENTERPRISE SERVICE BUS POWERED BY SPRING

ServiceMix JBI Container

Bindings for common Java Technologies◦ SOAP Bindings: plain HTTP/SOAP, jsr-181, X-Fire, ...◦ JMS Binding for plain JMS and JMS+SOAP◦ Quartz scheduler consumer binding◦ FTP provider and consumer◦ Bindings for JavaMail, HTTP, RSS, jabber ...

Service Engines◦ Generic Routing patterns: router, filter, splitter, aggregator, ...◦ XSLT transformation◦ Support for BPEL engines: Intalio PXE en Apache ODE◦ Support for Oracle XSQL

JBI Component Adaptors for POJO’s◦ Real POJO’s: use reflection◦ Implement JBI interfaces or use annotations

Using ServiceMix Deployment options

◦ Standalone container with hot-deploy◦ Bundled with Apache Geronimo J2EE container◦ JBoss deployer

Spring based configuration◦ XML namespaces avant la lettre

Code example