Search notes:
web service
Web services allow to
- query
- store
- calculate/manipulate
data on a dedicated server.
A web service can be contrasted to batch processes.
Features:
- Standardised by World Wide Web Consortium (W3C)
- Can (theoretically) be implemented in different technologies
- No definition how service looks like, but description posssible with WSDL.
One of the most significant characteristic of web services is their
loose coupling. Each service has its own
- Server they're running on
- Programming language
- Library version.
Web services typically send/return (strucuered) text in a non binary format. A web service usually does not return executable code.
BPEL: Business Process Execution Language
RDF: Resource Description Framework
REST: Representational State Transfer
RSS: Really Simple Syndication
SOAP: Simple Object Access Protocol
WSCL: Web Service Conversation Language
WSDL: Web Services Description Language. WSDL documents describe web services.
SOAP vs REST
REST is easier to learn.
| SOAP | REST |
access named operations (doStuff(userId)) | access named resources (getData(userId)) |
| XML | plain text, HTML, JSON, XML, CSV … |
| | HTTP |
| a protocol | archictural style |
| cannot use REST | can use SOAP |
| service interfaces | URIs |
| strict standards | loose standards |
| own security | security from underlying protocol (HTTPS?) |
Usually POST /.... plus interop | usually GET /service?do=something&id=42 |
| Built-in error handling | |