What are Big or SOAP Web Services?
We saw What are Web Services in our previous post, Big web services is one of the web services type which can be developed using JAX-WS implementation of Java EE 6.
It uses XML messages that follow the Simple Object Access Protocol (SOAP) standard, an XML language defining a message architecture and message formats. Such systems often contain a machine-readable description of the operations offered by the service, written in the Web Services Description Language (WSDL), an XML language for defining interfaces syntactically. Below image (courtesy) shows how communication between Client and Service happens using SOAP or Big web services
As in above diagram to communicate with web services, client must know some information for e.g.
- Location of webservices deployed server.
- Different functions available, functions signature and return types of function.
- Communication protocol used to communicate.
- Input and output formats
Different ways to share WSDL with clients:
There are two different types to share your WSDL:
- Clients which are going to consume web services are known in advance, then WSDL is provided to clients and clients can easily consume exposed services.
- Service provider can register its WSDL to UDDI and whomsoever wants to consume those services can search it on UDDI (Universal Description, Discovery and Integration). Below mentioned steps are done to do registering and searching on UDDI.
- Service provider registers its services with UDDI.
- Client searches for a particular service in UDDI.
- UDDI then 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.