Web Services Dynamic Invocation application

Table of Contents

• Overview of the Sample Application
• Application Usecase Diagram
• User Notes with Screen Shots
• Installation and Configuration
• Description of the Sample Files

This sample is an e-Business application that demonstrates Dynamic Invocation of Web Services. As we are aware, Web Services allow heterogeneous applications to invoke published methods through standard HTTP protocol. Most of the remote invocation technologies in the past operated at binary level and required tight coupling (Eg. Java RMI or CORBA) . However, Web Services have revolutionized all this with the use of XML, SOAP and HTTP. Web Services are loosely coupled because the data interchange happens in XML format over HTTP. We have two options by which we can consume Web Services

• Static Invocation
  Static invocation uses pre-generated stub. This stub corresponds to a WSDL specification agreed in advance.
  
  
• Dynamic Invocation
  Dynamic invocation generates the stub at the time of the method invocation. This stub is generated by parsing the WSDL document that describes the Web Service.
  

Oracle9iAS Web Services

Oracle provides complete infrastructure for development and deployment of Web Services. Oracle9i JDeveloper allows rapid development of Web Services. Oracle9iAS serves as the hosting platform where Web Services are hosted. Oracle9iAS containers for J2EE, an integral part of Oracle9iAS acts as the container where Web Services are deployed. Oracle provides necessary support classes that enable the developer to consume and develop a Web Service with minimal effort.

Oracle9iAS UDDI registry

As part of its Web Services products stack Oracle provides its own UDDI (Universal Description, Discovery and Integration) registry. Oracle's UDDI implementation runs on top of Oracle9iAS. UDDI registry allows service providers to publish their Web Services. UDDI registry allows clients to search these Web Services and find the service and WSDL url's. Once these locations are known, users can generate necessary stubs and consume these Web Services.

More about this application

This sample acts an insurance portal. Since there are hundreds of insurance service providers, people will always be interested in knowing if they are getting the best deal in insurance premiums. This application creates three vendors who sell insurance products. The only restriction on participating service providers is that they must host one Web Service that implements "QuoteService" interface. These service providers should register their services in the UDDI registry so that this portal can find all service providers.

This application browses through UDDI registry and maintains a list of all insurance vendors who provide "QuoteService". When user requests any information, this portal generates the stubs necessary for service invocation dynamically and retrieves the data. This data may be reformatted or sorted so that users have up-to-date information about the insurance products they are searching for.

When this sample is installed, it creates 3 database users. These users correspond to 3 insurance service providers.

1. GoodLife Insurance INC.
2. Fargo Insurance INC.
3. Western Insurance INC.

Every insurance provider provides a "QuoteService" implementation, so, there are 3 "QuoteService" providers. WSDL url and Service url of each of these Web Services is then added to UDDI registry along with related information. This application is ready to run once UDDI enquiry url for the UDDI registry is supplied to the QuoteAnalyzer component.

Users can go to the home page of this portal and have following search options.

Generic Search:

1. Get listing of all car insurance plans from all vendors.
2. Get listing of all life insurance plans from all vendors.
3. Get listing of all health insurance plans from all vendors.

Vendor Search:

1. Get listing of all car insurance plans from a particular vendor.
2. Get listing of all life insurance plans from a particular vendor.
3. Get listing of all health insurance plans from a particular vendor.
   

Best Search:

1. Get listing of all car insurance plans sorted in ascending order with respect to their premium.
2. Get listing of all life insurance plans sorted in ascending order with respect to their premium.
3. Get listing of all health insurance plans sorted in ascending order with respect to their premium.
   

This section shows the user a glimpse of the application.

Login screen when the application is invoked for the first time. (Ref Figure 1.1)

Figure 1.1

Refer to Install.html in the sample jar for step-by-step instructions on extracting files, installing and configuring any other systems to  successfully run this application.

The directory structure of the deliverable WebServiceDII.jar will be as shown below

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