Just Spring Integration

Spring Expressions

Spring Integration endpoints support Spring Expression Language (SpEL) definitions. You can use the expressions to evaluate the properties on headers and payloads. For example, if you wish to extract a header property using the expression, the following snippet will help:

<int:header-enricher id="enricher"
  input-channel="in-channel" output-channel="out-channel">

  <int:header name="TARGET_SYSTEM" expression="headers.TARGET_SYSTEM"/>
</int:header-enricher>

The headers property will have the reference to MessageHeaders, so you can query the properties using headers.property_name syntax.

Similarly, the payload is available as the payload property, so you can query the payload object’s variable by using dot notation:

<int:enricher input-channel="in-channel" 
  request-channel="enricher-req-channel" 
  output-channel="stdout">
  <int:property name="price" 
    expression="payload.price"/>
</int:enricher>

Endpoints such as Transformers, Filters, Service Activators, and Splitters support the Spring Expressions.