1 client connection
The client's connection refers to how the customer accesses your network service. Table 1 shows three main customer types connected to network services.
Table 1 Customer connection method
Customer type
Example
This kind of customer connection method
Business Partners
Sponsor (DISTRIBUTORS), Salers, Large Customers
XML-based network service technology (SOAP, UDDI, WSDL, EBXML)
Thin Clients
Browser, PDA, wireless device
Lightweight, Lightweight Protocol, such as HTTP
THICK Clients
Applets, application, existing system
Weavy, complex protocol (Heavyweight Protocol) such as IIOP.
1.1 Business partner connection
Business partners can get special web services. Business partners can connect with different programming languages, middleware, and hardware. Therefore, when a business partner accesses your system, the network service request appears in XML. XML is a standard meta-marker language (META-MARKUP LANGUAGE) can be used for commercial data and allowing heterogeneous systems to interact.
1.1.1 java servlets
When a business partner issues a network service request, receive the XML document is Java servlets. A servlets is a Java object based on request / response that runs in a manageable container environment. It can respond to requests that use any protocol (such as HTTP, FTP, or POP). In this case, servlets is used to respond to the HTTP request, because network services use HTTP services to make communication across firewalls possible.
When a request enters a J2EE network service system, there is an ordered operation as shown in FIG. 2.
Java servlet gets an XML document
XML-based request obtained by servlet processing
Then, servlet calls one or more Enterprise JavaBeans (EJB) components to complete business data processing
The function of the external system may call the external system when the EJB component is processed.
EJB component returns data to servlet
Then, the servlet conversion return value is an XML document.
Servlet returns XML to your client as an answer
Figure 2: Request for a business partner
1.1.2 UDDI
Before the business partner is able to start a business network service call, it must first find where the business service is available, discovers the interface and semantics of the call to start configuring software and services in their end. Therefore, we need tools to publish our services.
UDDI (Universal Description, Discovery, and Integration) is a very important new project that is used for web services providing and search. The UDDI project provides a service called UBR (UDDI Business Registry), which is a global transaction and service public directory. Network service providers can register and describe their services with UBR. Users can query UBR to discover network services and obtain information with service interoperability.
UDDI provides a mechanism for the description document for a guideline system to find a specific service. UDDI includes standard "White pages" types search and "Yellow Pages" type topics search, also have "Green Pages" type of service type searches. "Green Page" search. Enables developers to find all services in a service type.
UDDI uses SOAP messages (typical forms to XML / HTTP) to publish, edit, browse, and find information in registry. It also includes XML Schema to encapsulate registry services (Registry Service) to send or return different types of data. 1.1.3 JAXR
In order to support the implementation of the UDDI function on the Java platform, Java APIS for XML Registries (JAXR) is an API specification that will be developers to be developed to access the registry. It is worth noting that JAXR is not currently necessary, and you can still use more common XML APIs to interact with protocols. JAXR is a Java API that provides a variety of publishing, query, and editing registry supporting. It focuses primary focus on network services for B2B applications, and provides complex content queries and publish / subscribes to XML messages. It can also be used to access other types of registry, such as EBXML REGISTRY (later we will talk).
1.1.4 WSDL
In order to let the merchant find the service it wants, the syntax and semantics of the network service call need to be determined before the call. The WSDL (Web Services Description Language) specification is an XML document describing network service interface, semantic, and daily repetitive work (Interface, Semantics, And Adminicia). It allows simple services to be quickly and easy to describe and archive.
Here is a WSDL definition:
TargetNamespace = "http://example.com/stock quote.wsdl" XMLns: TNS = "http://example.com/stockquote.wsdl" XMLns: xsd1 = "http://example.com/stock quote.xsd" XMLns: soap = "http://schemas.xmlsoap.org/wsdl/soap/" XMLns = "http://schemas.xmlsoap.org/wsdl/"> XMLns = "http://www.w3.org/2000/10/xmlschema"> TYPE = "TNS: stockquoteporttype"> Transport = "http://schemas.xmlsoap.org/soap/http" /> SOAPACTION = "http://example.com/getlasttradeprice" /> It includes the following key information: l The description / format of a message. It can be passed in l Semantics in the message transfer in the l Specific encoding in l The server address (a URL) in the In Java Community Process (JCP), the Java API for WSDL (JWSDL) specification is underway. When it is published, the API will be provided to process the WSDL document instead of processing the XML document directly. When you can use JAXP's function, you can use JWSDL easier and fast, which simplifies developers' work. Figure 3 shows WSDL and UDDI Figure 3 Using JAXR, UDDI and WSDL
