构成S0A的技术 什么是服务 服务调用 服务的编排 服务的发现
6 构成SOA的技术 ▪ 什么是服务 ▪ 服务调用 ▪ 服务的编排 ▪ 服务的发现
什么是服务? A well-defined invokable unit of business function Accesses business data or facilitates a change of business data from one valid and consistent state to another Defined using explicit interfaces Independent of service implementations Provides contract between service requestors and service providers Invokable through common communication protocols Provides interoperability and location transparency
7 什么是服务? ▪ A well-defined, invokable unit of business function ▪ Accesses business data or facilitates a change of business data from one valid and consistent state to another. ▪ Defined using explicit interfaces Independent of service implementations Provides contract between service requestors and service providers ▪ Invokable through common communication protocols Provides interoperability and location transparency
服务描述 Services are described using a standardized interface(metadata Defines the service, its operations, and input and output parameters Defines how the service is reached and its location Input and outputs may be simple parameters or XML documents An existing application can be given a service facade The facade(e.g. an EJB)is then described as the service Web Services Description Language(WSDL)is the standard used to describe the service
8 服务描述 ▪ Services are described using a standardized interface (metadata) Defines the service, its operations, and input and output parameters Defines how the service is reached and its location ▪ Input and outputs may be simple parameters or XML documents ▪ An existing application can be given a service ‘façade’ The façade (e.g. an EJB) is then described as the service ▪ Web Services Description Language (WSDL) is the standard used to describe the service
服务描述:WSDL Services Bindings Port T Messages B:PurchaseOrderService 由凶 Purchase OrderRequest 日 D Binding e ims: binding 日降 Create Purchase OrderResponse e jms address e format: type u Return BodyPart 0 田 Create outp I StatusPart (xsd: string) 49 Delete DescriptionPart [xsd: string) 团@ Retrieve 田 Retrieve I JMS TypePart (xsd: string) 团、@, Update 田 Update WSDL (Web Services Description Language) is an XML document that describes a service using a number of key elements A Port Type defines what the service does, and is described by a number of operations For each operation the data that it receives and sends is described by a Message The Binding defines how the service(as described by the Port Type) is invoked e. g Soap/Http Soap/Jms The Port specifies the address where the service is located
9 服务描述: WSDL ▪ WSDL (Web Services Description Language) is an XML document that describes a Service using a number of key elements: A Port Type defines what the service does, and is described by a number of operations. For each operation the data that it receives and sends is described by a Message The Binding defines how the service (as described by the Port Type) is invoked e.g. SOAP/HTTP, SOAP/JMS. The Port specifies the address where the service is located