In this post,we will see introduction to SOAP web services.
Web service Tutorial Content:
Part-1:Introduction to web services Part-2:SOAP web service introduction Part-3:RESTful web service introduction Part-4:SOAP web service example in java using eclipse Part-5:JAX-WS web service eclipse tutorial Part-6:JAX-WS web service deployment on tomcat Part-7:Create RESTful web service in java(JAX-RS) using jersey
Simple Object Access Protocol (SOAP) is a standard protocol specification for message exchange based on XML. Communication between the web service and client happens using XML messages.
A simple web service architecture have two components
- Service provider
- Location of webservices server
- Functions available,signature and return types of function.
- Communication protocol
- Input output formats
What is WSDL?WSDL stands for Web Service Description Language. It is an XML file that describes
the technical details of how to implement a web service, more specifically the URI,
port, method names, arguments, and data types. Since WSDL is XML, it is both
human-readable and machine-consumable, which aids in the ability to call and bind to
services dynamically.using this WSDL file we can understand things like,
- Port / Endpoint – URL of the web service
- Input message format
- Output message format
- Security protocol that needs to be followed
- Which protocol the web service uses
Ways to access web service:
There are two ways to access web service.
- If Service provider knows client:If service provider knows its client then it will provide its wsdl to client and client will be able to access web service.
- Service provider register its WSDL to UDDI and client can access it from UDDI:UDDI stands for Universal Description, Discovery and Integration.It is a directory service. Web services can register with a UDDI and make themselves available through it for discovery.So following steps are involved.
- Service provider registers with UDDI.
- Client searches for service in UDDI.
- UDDI returns all service providers offering that service.
- Client chooses service provider
- UDDI returns WSDL of chosen service provider.
- Using WSDL of service provider,client accesses web service.