1. Web-Services-based Systems Architecture, Design and Implementation
B.Ramamurthy
11/17/2018

2. Goals Artifacts of a large scale distributed system
Architecting a services-based system
Design issues in services-based system
Anything else…
11/17/2018

3. Develop/Deploy(DD) Cycle
Service
Endpoint
Interface
wscompile
Portable
Artifacts
WSDL
Model
wsdeploy
Deployment
Descriptors
Cooked WAR
11/17/2018

4. Invocation Model (client side) or Invoke Cycle
wscompile
Portable
Artifacts
WSDL
Implementation
-specific
Artifacts
Client
Invoke web service
11/17/2018

5. Client Scenarios Service endpoint interface Web service 2 WSDL
JSP
Client
Java App.
Client
Servlet
Client
11/17/2018

6. Artifacts: the server/container
Host with an IP (and ports)
Web servers, servlet servers, application servers
All can be bundled into one
More than one can be installed in a “host” machine at different port s
Each has a context root, the path of which represents the root page for that server
Each has an admin console for managing the server resources such a data source and message queues.
Elegant way to access the resources in a deployed unit is through the container (server).
For java, you will define JNDI (Java Naming and Directory Interface) names for the resources.
Portability of deployable units (Ex: ‘Component technology’: Enterprise Java beans)
11/17/2018

7. Artifacts: the data Relational data base; object relational database
Data modeling (Entity-Relationship modeling)
Tables
Operations
Data access objects (DAO)
Enterprise java beans (EJB)
Enterprise information system (Amazon.com webservices, yahoo feeds)
Legacy systems
Device data (sensors)
RSS, ATOM, XML and text feeds
11/17/2018

8. Artifacts: the services
WS creation for consumption:
Typically create a service from language-dependent interface/class (Ex: Java interface + class)
Generate WSDL for publication and consumption.
WS consumption using a published WSDL.
Generate the language-dependent classes from WSDL
Understand thoroughly the various components of the WSDL: messages, port type, bindings, server (server, port), etc.
Protocols: SOAP, REST (For project 1 you may use either)
11/17/2018

9. Artifacts: the clients
Simple applications to rich client (ex: RIA rich internet application)
Internationalization (languages, monitory units, etc.)
HTTP monitors, cookies and counters
Preference profiles
11/17/2018

10. Component Technology
We need an application architecture that works well in the new E-commerce age.
Programmer productivity, cost-effective deployment, rapid time to market, seamless integration, application portability, scalability, security are some of the challenges that component technology tries to address head on.
Enterprise Java Beans is Sun’s server component model that provides portability across application servers, and supports complex systems features such as transactions, security, etc. on behalf of the application components.
EJB is a specification provided by Sun and many third party vendors have products compliant with this specification: BEA systems, IONA, IBM, Oracle.
11/17/2018
B. Ramamurthy

11. Two-tier applications
Presentation
Logic
Business
Database
Server
11/17/2018
B. Ramamurthy

12. Three-tier Applications
Presentation
Logic
Business
Database
Server
11/17/2018
B. Ramamurthy

13. J2EE Application Programming Model for Web-based applications
Web Service
Business Logic
Web
Application
Database
Server
Enterprise
Java Beans
EJB container
Web Container
Web
client
11/17/2018
B. Ramamurthy

14. J2EE Application Programming Model for Three-tier Applications
Presentation
Components
Database
Server
Enterprise
Java Beans
EJB container
Application
Container
Business Logic
11/17/2018
B. Ramamurthy

15. J2EE Application Programming Model for Web-based Applets
Web Service
Business Logic
Web
Application
Container
Enterprise
Java Beans
EJB container
Browser
Database
Server
Applet
internet
11/17/2018
B. Ramamurthy