1. Web Services Martin Smítka

2. Description The main idea behind Web Services is that back-end application comunicate with another back-end application without human interference. Web Services are based on standardized technologies of W3C (World Wide Web Consortium)

3. Web Service architecture

4. Cornerstone Technologies Cornerstone Technologies HTTP (Hypertext Transfer Protocol) HTTP (Hypertext Transfer Protocol) XML (eXtensible Markup Language) XML (eXtensible Markup Language) SOAP (Service-Oriented Access Protocol)SOAP (Service-Oriented Access Protocol)SOAP (Service-Oriented Access Protocol)SOAP (Service-Oriented Access Protocol) WSDL (Web Services Definition Language)WSDL (Web Services Definition Language)WSDL (Web Services Definition Language)WSDL (Web Services Definition Language) UDDI (Universal Description, Discovery and Integration)UDDI (Universal Description, Discovery and Integration)UDDI (Universal Description, Discovery and Integration)UDDI (Universal Description, Discovery and Integration)

5. WSDL WSDL document is well-formed XML document that contains list of publicly accessible functions with related input and output parametrs, binding and adress information for Web Service (usually URI) and list of transport protocols for invoking service.

6. UDDI UDDI is distributed repository that clients search to find Web Services. White pages - There are stored information about service providers and description of the business. White pages - There are stored information about service providers and description of the business. Yellow pages - There are stored classification of the company and service provided according to standard taxonomies. Yellow pages - There are stored classification of the company and service provided according to standard taxonomies. Green pages - There are stored technical information about the service provided including the location adress. Green pages - There are stored technical information about the service provided including the location adress.

7. SOAP SOAP provides lightweight protocol for exchanging data, invoking applications remotely and handling exceptions. SOAP provides lightweight protocol for exchanging data, invoking applications remotely and handling exceptions.

8. Security over SOAP SOAP messages are being sent over secured HTTP is not adequate method of security implementation for a few reasons: Secured HTTP can be established only between two end points. If SOAP message must cross more jumps, the secured HTTP can not be used.Secured HTTP can be established only between two end points. If SOAP message must cross more jumps, the secured HTTP can not be used. If SOAP message is processed by more than one back-end application secured HTTP can not be used.If SOAP message is processed by more than one back-end application secured HTTP can not be used. If there is need to encrypt/sign only part of a message or there is need to encrypt/sign more parts by different encryption methods.If there is need to encrypt/sign only part of a message or there is need to encrypt/sign more parts by different encryption methods.

9. Drawbacks of Web Services Nghiem [Ng 2003] divides drawbacks into these groups: Audit trail – an audit trail provides a journal to resolve exception conditions or to confirm commitments of one or both parties.Audit trail – an audit trail provides a journal to resolve exception conditions or to confirm commitments of one or both parties. Guaranteed delivery – ensures that a message is guaranteed to be delivered to the recipient.Guaranteed delivery – ensures that a message is guaranteed to be delivered to the recipient. Provisioning – in delivering Web Services to the enterprise, a common challenge is how to turn the service on for an authorized user and turn the service off.Provisioning – in delivering Web Services to the enterprise, a common challenge is how to turn the service on for an authorized user and turn the service off. Security enforcement – users should be able to access only those services for which they are authorizedSecurity enforcement – users should be able to access only those services for which they are authorized VersioningVersioning Service-level agreement (SLA terms) – in order to enforce an SLA, there must be metrics that record the reliability and performance of the two endpoints.Service-level agreement (SLA terms) – in order to enforce an SLA, there must be metrics that record the reliability and performance of the two endpoints.

10. Web Services Networks They connect individual Web Services under one infrastructure targeting above mentioned problems.

11. Benefits of WS Networks Protocol mediation Protocol mediation Data transformation Data transformation Compression Compression Streaming Streaming Persistent messaging Persistent messaging Security features Security features Diagnosticity Diagnosticity

12. Web Services Thank you for your attention