graph://ask

Executes a SPARQL ASK query against the RDFGraph in the exchange body. The result is a boolean — true if the graph contains at least one match for the query pattern, false otherwise. This is useful for validation checks and conditional routing.

The query can be provided either inline as a string or loaded from an external file via a ChimeraResource.

Parameters

Parameter	Type	Required	Default	Description
query	String	No*	—	Inline SPARQL ASK query string.
chimeraResource	ChimeraResourceBean	No*	—	Resource pointing to a file containing the SPARQL ASK query. See ChimeraResource.

*At least one of query or chimeraResource must be provided.

Example

Java DSLYAML

from("direct:check")
    .setVariable("q", constant("ASK WHERE { ?s a <http://example.org/Person> }"))
    .toD("graph://ask?query=${variable.q}")
    .choice()
        .when(body().isEqualTo(true))
            .to("direct:found")
        .otherwise()
            .to("direct:notFound");

- route:
    from: "direct:check"
    steps:
      - setVariable:
          name: q
          constant: "ASK WHERE { ?s a <http://example.org/Person> }"
      - toD: "graph://ask?query=${variable.q}"
      - choice:
          when:
            - simple: "${body} == true"
              steps:
                - to: "direct:found"
          otherwise:
            steps:
              - to: "direct:notFound"