WEB SERVICE INTRODUCTION

WEB SERVICES

Web service is a way of calling methods of one application (Which is deployed in Web server) from another application.

    

Advantages:

The main advantage of web service is the web service consumer need not to have the platform under which web service is deployed.

For example the web service which is developed under Microsoft Dotnet can easily invoke and get output by java client.

The key point beyond this is

All web services are available to consumers as XML files. And we call them as WSDL (Web service description language)

All technologies are following same standards while generating the WSDL file. So WSDL which is generated by the technology like MS.net can easily invoked by java client.

The standard protocol they are following is SOAP protocol.

• SOAP is a communication protocol which defines message format.
• The information in WSDL in the format of SOAP. (Simple Object Access Protocol)
• And client should be in network like internet or LAN.

And we may have different transports in network. The transports may be

1) HTTP

2) JMS etc.

If transport is HTTP then we call that as SOAP over HTTP.

If transport is JMS then,SOAP over JMS.

This means the WSDL file containing SOAP information can be transported between Web service provider and web service Consumer by the transport HTTP or JMS over network.

The concept of Web service can be achieved by TIBCO BW also.

• Tibco BW can consume webservice as a client for Web service.
• Tibco BW can provide service as Web service provider.

When Tibco BW acts as Web service provider

The business logic can be exposed as Web service with the help of

1. Soap event source (or)
2. Service resource.

SOAP event source is helpful only in the case when we are exposing single process definition as web service.

if we use service resource we can expose multiple process definitions as a web service over different transports for each process definition