Sets an exchange property to a constant string or a computed value. Unlike a header or the body, a property is not sent to the client; it is only readable by later interceptors in the same exchange, e.g. as ${property.name} in a template or another expression. The value is evaluated as a SpEL template, Groovy, JsonPath, or XPath expression, defaulting to SpEL. See tutorials/orchestration/30-Orchestration.yaml.
When true, aborts processing if expression evaluation fails. When false, logs the error and continues unchanged.
false
ifAbsent
false
false
When true, only sets the field if it is not already present in the message.
true
language
false
SpEL
Scripting language used to evaluate the value expression.
SpEL | groovy | jsonpath | xpath
name
false
-
Name of the header field or exchange property key to set.
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value
false
-
Value to assign, evaluated as a SpEL template expression by default. Use the language attribute to switch to Groovy, JsonPath, or XPath.
XPath and JSONPath query the body. An empty body, or one of another media type, is evaluated as an empty document, so the expression finds nothing, as when the queried element or field is missing. A body that should be XML or JSON but does not parse is an error: 400 in the request, 502 in the response, unless failOnError is false.
