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Get (Metadata Exchange) HTTP Request and Message

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A Get message is a WS-Transfer message used to request metadata. For more information about Get messages, see section 3.1 of the WS-Transfer Specification. Because metadata exchange is done over HTTP, a Get message is the payload of an HTTP request.

DPWS clients send Get messages. Function Discovery clients, WSDAPI clients calling WSDCreateDeviceProxy, and WSDAPI clients calling WSDCreateDeviceProxyAdvanced send this message.

Note

This topic shows a sample DPWS message generated by WSDAPI clients and hosts. WSDAPI will parse and accept other DPWS-compliant messages that do not conform to this sample. Do not use this sample to verify DPWS interoperability; use the WSDAPI Basic Interoperability Tool (WSDBIT) instead.

 

The following example shows a sample Get HTTP request.

POST /37f86d35-e6ac-4241-964f-1d9ae46fb366
HTTP/1.1
Content-Type: application/soap+xml
User-Agent: WSDAPI
Host: 192.168.0.2:5357
Content-Length: 658
Connection: Keep-Alive
Cache-Control: no-cache
Pragma: no-cache

A Get HTTP request has the following focus points.

Focus point Header Line Description
URL Path 
POST /37f86d35-e6ac-4241-964f-1d9ae46fb366
 The URL path where the Get HTTP request was posted.
Host and Port 
Host: 192.168.0.2:5357
 The host and port where the Get HTTP request was directed.

 

The following SOAP message shows a sample Get message.

<?xml version="1.0" encoding="utf-8" ?>
<soap:Envelope
    xmlns:soap="https://www.w3.org/2003/05/soap-envelope"
    xmlns:wsa="https://schemas.xmlsoap.org/ws/2004/08/addressing">
<soap:Header>
    <wsa:To>
        urn:uuid:37f86d35-e6ac-4241-964f-1d9ae46fb366
    </wsa:To>
    <wsa:Action>
        https://schemas.xmlsoap.org/ws/2004/09/transfer/Get
    </wsa:Action>
    <wsa:MessageID>
        urn:uuid:027bec45-c37c-466c-936c-68f648abe2bb
    </wsa:MessageID>
    <wsa:ReplyTo>
        <wsa:Address>
            https://schemas.xmlsoap.org/ws/2004/08/addressing/role/anonymous
        </wsa:Address>
    </wsa:ReplyTo>
    <wsa:From>
        <wsa:Address>
            urn:uuid:49e131df-351a-4ece-9a6f-6a862d31cffa
        </wsa:Address>
    </wsa:From>
</soap:Header>
<soap:Body>
</soap:Body>

A Get message has the following focus points.

Focus point XML Description
To 
<wsa:To>
    urn:uuid:37f86d35-e6ac-4241-964f-1d9ae46fb366
</wsa:To>
 The identifier of the device being asked for metadata.
Get 
<wsa:Action>
    https://schemas.xmlsoap.org/ws/2004/09/transfer/Get
The Get SOAP action identifies the message as a Get message.
MessageID 
<wsa:MessageID>
    urn:uuid:027bec45-c37c-466c-936c-68f648abe2bb
Contains the message identifier, which is referenced in a GetResponse message.

 

Discovery and Metadata Exchange Messages

GetResponse Message