"WCF Technology Insider" translation 12:1th Part _ 2nd Chapter _ Service-oriented: Concept summary

Concept Summary

I hope you have a clear understanding of service orientation from this section of this chapter. In the next few chapters, let's look at how these concepts work in a WCF system. In our example, I talk about building a simple order Processing service that accepts customer orders. To keep the concept simple and straightforward, there are 2 message participants, as shown in Figure 2-3.

Figure 2-3: A simple example of a message exchange

The purpose of this sample code is to enhance your knowledge of the service and provide WCF introductions, not to describe all aspects of WCF or to establish a complete functional order processing system. The type and mechanism in the example will be described in detail in this book.

Contract

Obviously, service-oriented system development should first be to create a contract. For the simple example, an order contains a product ID, a quantity (quantity), and a status message. With these three fields, an order can be represented using the following pseudo schema code:

<Order>
　 <ProdID>xs:integer</ProdID>
　 <Qty>xs:integer</Qty>
　 <Status>xs:string</Status>
</Order>

From our message autonomy and configuration address discussion, we know that messages require more address structures if we want to use ws-addressing. In our Order Processing service, message senders and receivers uniformly use SOAP messages that adhere to the Ws-addressing specification to restrict the structure of the message. With this rule, here is an example of a reasonably structured message:

<s:Envelope　xmlns:s="http://www.w3.org/2003/05/soap- envelope"　xmlns:wsa="http://
schemas.xmlsoap.org/ws/2004/08/addressing">
　 <s:Header>
　　　　 <wsa:Action　 s:mustUnderstand="1">urn:SubmitOrder</wsa:Action>
　　　　 <wsa:MessageID>4</wsa:MessageID>
　　　　 <wsa:ReplyTo>
　　　　　　 <wsa:Address>　 http://schemas.xmlsoap.org/ws/2004/08/addressing/role/anonymous
　　　　　　 </wsa:Address>
　　　　 </wsa:ReplyTo>
　　　　 <wsa:To　 s:mustUnderstand="1">http://localhost:8000/Order</wsa:To>
　 </s:Header>
　　 <s:Body>
　　　　 <Order>
　　　　　　 <ProdID>6</ProdID>
　　　　　　 <Qty>6</Qty>
　　　　　　 <Status>order　placed</Status>
　　　　 </Order>
　 </s:Body>
</s:Envelope>