我需要过滤SOAP Web服务的响应。由于SOAP基于XML,我正在考虑使用libxml2,但我无法理解如何编写XPath表达式来实现所需的结果。
在邮件末尾,您会找到一个响应示例,其中发送了两个NotficationMessages,一个主题为tns1:RuleEngine/LineDetector/Crossed
,另一个主题为tns1:RuleEngine/CellMotionDetector/Motion
。
我正在尝试编写以下XPath表达式:
tns1:RuleEngine/LineDetector/Crossed
tns1:RuleEngine//.
tns1:RuleEngine//.
我发现的所有示例都与属性匹配,而不是子元素的内容。
所以我在问。
<?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope
xmlns:SOAP-ENV="http://www.w3.org/2003/05/soap-envelope"
xmlns:wsa="http://www.w3.org/2005/08/addressing"
xmlns:wstop="http://docs.oasis-open.org/wsn/t-1"
xmlns:wsnt="http://docs.oasis-open.org/wsn/b-2"
xmlns:tet="http://www.onvif.org/ver10/events/wsdl"
xmlns:tns1="http://www.onvif.org/ver10/topics"
xmlns:tt="http://www.onvif.org/ver10/schema">
<SOAP-ENV:Header>
<wsa:Action> http://www.onvif.org/ver10/events/wsdl/PullPointSubscription/PullMessagesResponse
</wsa:Action>
</SOAP-ENV:Header>
<SOAP-ENV:Body>
<tet:PullMessagesResponse>
<tet:CurrentTime>
2008-10-10T12:24:58
</tet:CurrentTime>
<tet:TerminationTime>
2008-10-10T12:25:58
</tet:TerminationTime>
<wsnt:NotificationMessage>
<wsnt:Topic Dialect="http://www.onvif.org/ver10/tev/topicExpression/ConcreteSet">
tns1:RuleEngine/LineDetector/Crossed
</wsnt:Topic>
<wsnt:Message>
<tt:Message UtcTime="2008-10-10T12:24:57.321Z">
<tt:Source>
<tt:SimpleItem Name="VideoSourceConfigurationToken"
Value="1"/>
<tt:SimpleItem Name="VideoAnalyticsConfigurationToken"
Value="2"/>
<tt:SimpleItem Value="MyImportantFence1" Name="Rule"/>
</tt:Source>
<tt:Data>
<tt:SimpleItem Name="ObjectId" Value="15" />
</tt:Data>
</tt:Message>
</wsnt:Message>
</wsnt:NotificationMessage>
<wsnt:NotficationMessage>
<wsnt:Topic Dialect="http://www.onvif.org/ver10/tev/topicExpression/ConcreteSet">
tns1:RuleEngine/CellMotionDetector/Motion
</wsnt:Topic>
<wsnt:Message>
<tt:Message UtcTime= "2010-10-20T12:24:57.628">
<tt:Source>
<tt:SimpleItem Name="VideoSourceConfigurationToken" Value="1"/>
<tt:SimpleItem Name="VideoAnalyticsConfigurationToken" Value="1"/>
<tt:SimpleItem Name="Rule" Value="MotionInDefinedCells"/>
</tt:Source>
<tt:Data>
<tt:SimpleItem Name="IsMotion" Value="true"/>
</tt:Data>
</tt:Message>
</wsnt:Message>
</wsnt:NotficationMessage>
</tet:PullMessagesResponse>
</SOAP-ENV:Body>
</SOAP-ENV:Envelope>
答案 0 :(得分:0)
您需要的只是使用location paths和predicates的基本XPath表达式:
匹配任何主题为tns1:RuleEngine/LineDetector/Crossed
//wsnt:NotificationMessage[wsnt:Topic = 'tns1:RuleEngine/LineDetector/Crossed']
匹配任何主题为tns1:RuleEngine//.
//wsnt:NotificationMessage[wsnt:Topic = 'tns1:RuleEngine//.']
匹配任何NotficationMessage,其主题是除tns1:RuleEngine//.
//wsnt:NotificationMessage[wsnt:Topic != 'tns1:RuleEngine//.']