WSDL学习笔记1——WSDL支持的4种消息交换方式
??? WSDl定义了4种操作类型，其中请求-响应是最普通的操作类型：
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类型定义???? One-way???? 此操作可接受消息，但不会返回响应。???? Request-response???? 此操走可接受一个请求并会返回一个响应???? Solicit-response???? 此操作可发送一个请求，并会等待一个响应。???? Notification???? 此操作可发送一条消息，但不会等待响应。?
?? 1、One - way 操作
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??? 一个one - way 操作的例子：
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<message name = "newTermValues"> <part name = "term" type = "xs:string"/> <part name = "value" type = "xs:string"> </message> <portType name = "glossaryTerms"> <operation name = "setTerm"> <input name = "newTerm" message = "newTermValues"/> </operation> </portType>?
??? 在这个例子中, 端口 “glossaryTerms” 定义了一个名为 “setTerm” 的 one-way 操作。
??? 这个 “setTerm” 操作可接受新术语表项目消息的输入, 这些消息使用一条名为 “newTermValues” 的消息, 此消息带有输入
??? 参数 “term” 和 “value”。不过, 没有为这个操作定义任何输出。
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??? 2、Request - Response 操作
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??? 一个 request-response 操作的例子：
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<message name = "getTermRequest"> <part name = "term" type = "xs:string"> </message> <message name = "getTermResponse"> <part name = "value" type = "xs:string"/> </message> <portType name = "glossaryTerms"> <operation name = "getTerm"> <input message = "getTermRequest"/> <output message = "getTermResponse"/> </operation> </portType>
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??? 在这个例子中, 端口 “glossaryTerms” 定义了一个名为 “getTerm” 的 request-response 操作。
??? “getTerm” 操作会请求一个名为 “getTermRequest” 的输入消息, 此消息带有一个名为 “term” 的参数, 并将返回一个名为
??? “getTermResponse” 的输出消息, 此消息带有一个名为 “value” 的参数。
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??? 《JAVA WebService》一书中, P88页：
??? 5.2.5 <portType> Element
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??? The <portType> element specifies a subset of operations supported for an endpoint of a web service. In a
??? sense, a <portType> element provides a unique identified to a group of actions that can be executed at a
??? single endpoint.
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??? The <operation> element represents an operation. This element is an abstract definition of an action
??? supported by a web service. A WSDL <operation> element is analogous to a Java method definition. A WSDL
??? operation can have input and output messages as part of its action. The <operation> tag defines the name
??? of the action by using a name attribute, defines the input message by the <input> subelement, and defines
??? the output message by the <output> subelement. The <input> and <output> elements reference
??? <message> elements defined in the same WSDL document or an imported one. A <message> element can
??? represent a request, response, or a fault.
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??? Continuing with the Z39.50 ASN.1 sample, the WSDL file defines a single <portType> element:
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??? <portType name = "ez3950PortTypes">
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??? This element declares that this endpoint has a set of operations that jointly referenced as ez3950PortTypes.
??? The following lines define the <operation> elements for this <portType>:
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<portTyle><!-- Request-response Operations (client initiated) --> <operation name = "iniit"> <input message = "initRequest"/> <output message = "initResponse"/> </operation> <operation name = "search"> <input message="searchRequest"/> <output message="searchResponse"/> </operation> <operation name="present"> <input message="presentRequest"/> <output message="presentResponse"/> </operation> <operation name="sort"> <input message="sortRequest"/> <output message="sortResponse"/> </operation> <operation name="scan"> <input message="scanRequest"/> <output message="scanResponse"/> </operation> <operation name="delete"> <input message="deleteRequest"/> <output message="deleteResponse"/> </operation> <operation name="resourceReport"> <input message="resourceReportRequest"/> <output message="resourceReportResponse"/> </operation> <operation name="extendedServices"> <input message="extendedServicesRequest"/> <output message="extendedServicesResponse"/> </operation> <operation name="close"> <output message="close"/> <input message="close"/> </operation><!-- Solicit-response Operation (Server initiated) --> <operation name = "accessControl"> <output message = "accessControlResponse"/> <input message = "accessControlRequest"/> </operation> <operation name = "resourceControl"> <output message="resourceControlResponse"/> <input message="resourceControlRequest"/> </operation> <operation name="close"> <output message="close"/> <input message="close"/> </operation><!-- Notification Operations (Server initiated) --> <operation name = "segmenty"> <output message = "segmentRequest"/> </operation><!-- One-way Operations (Client initiated) --> <operation name = "triggerResourceControl"> <input message = "triggerResourceControlRequest"/> </operation></portType>
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??? These <operation> elements are grouped according to their behavior. When an operation is defined in a
??? WSDL document, it is made to be abstract; it is purely an operation definition, but how that operation is
??? mapped to a real function is defined later (i.e., the operation can behave in a number of different ways
??? depending on the actual definition). The WSDL specification defines the following behavioral patterns as
??? transmission primitives:
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? Request-response? Solicit-response? One-way? Notification??? First, the operation can follow a request-response model, in which a web service client invokes a request
??? and expects to receive a synchronous response message. This model is defined by the presence of both
??? <input> and <output> elements. The <input> element must appear before the <output> element. This order
??? indicates that the operation first accepts an input message (reqeust) and then sends an output message
??? (response). This model is similar to a normal procedure call, in which the calling method blocks until the called
??? method returns its result.
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??? Second, the operation can follow a solicit-response model, in which the web service solicits a response from
??? the client, expecting to receive a response. This model is defined as having both <input> and <output>
??? elements. The <output> element must appear before the <input> element. This order indicates that the
??? operation first sends an output message (solicit) and then receives an input message (response).
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??? Third, the operation can be a one-way invocation, in which the web sevice client sends a message to the
??? web service without expecting to receive a response. This model is defined by a single <input> message
??? with no <output> message. This model indicates that the operation receives input messages (one-way
??? invocation), but doesn't deliver a response to the client.
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??? Fourth, the operation can be a notification, in which the web services sends a one-way message to the client
??? without expecting a response. This model is defined by a single <output> message and no <input>
??? message. It indicates that the operation sends output messages asynchronously; i.e., the messages are not
??? in response to a request, but can be sent at any time. The operation doesn't expect a response to the
??? messages it sends.
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??? annotate:
??? For the request-response and solicit-response models, an optional <fault> element can be
??? included. This element refers to another message. A <fault> message will be transmitted
??? if any processing, system, or application errors occur. The <fault> message is delivered to
??? the client in a request-response and to the web service in the solicit-response model.
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??? The value assigned to the name attribute of each <operation> element must be unique within the scope of
??? the <portType>, not just the <operation>. The value assigned to the message attrubute of an <input> or
??? <output> element must match one of the names of the <message> elements defined in the same WSDL or
??? in an imported one.
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