There are use cases in which the header schemas cannot be determined from the WSDL files. For example, security headers that are appended to a message, or the headers for a Mediator that are created using an abstract WSDL file. To access these headers, you must manually enter the XPath expression into the Expression Builder.

The syntax for header expressions is shown in the following example:

$in.header.<header root element namespace prefix>_<header root element name>/<xpath>

Therefore, for the header shown in the following example:

<wsse:Security xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-sec
ext-1.0.xsd">
<Priority>234</Priority>
</wsse:Security>

The filter expression is as follows:

$in.header.wsse_Security/wsse:Security/Priority = '234'

The assignment expression is as shown in the following example:

<copy target="$out.property.jca.jms.priority"
 expression="$in.header.wsse_Security/wsse:Security/Priority"/>

For the preceding expressions to work, you must add the attribute shown in the following example to the root element of the .mplan file.

wsse = "http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-
secext-1.0.xsd"