Infinite Recursion

[Jean-Karlo Accetta]

Hi,


I'm using Spring Boot to return some results from a HAPI FHIR backend. I'm getting an infinite recursion error when trying to return a Bundle from a generic rest client. Here's the code snippet:

@GetMapping(value = {"/condition/", "/condition"})
public Bundle getAll() {
 Bundle bundle = clinacuityProperties.getFhirContext().newRestfulGenericClient(url)
 .search()
 .forResource(Condition.class)
 .returnBundle(Bundle.class)
 .execute();

 return bundle;

}

Here's the error that I'm running into:

org.springframework.http.converter.HttpMessageNotWritableException: Could not write JSON: Infinite recursion (StackOverflowError); nested exception is com.fasterxml.jackson.databind.JsonMappingException: Infinite recursion (StackOverflowError) (through reference chain: org.hl7.fhir.dstu3.model.StringType["idElement"]->org.hl7.fhir.dstu3.model.StringType["idElement"]->org.hl7.fhir.dstu3.model.StringType["idElement"]-> [. . . repeats several hundred times . . .] ->org.hl7.fhir.dstu3.model.StringType["idElement"]->org.hl7.fhir.dstu3.model.StringType["formatCommentsPre"])

(There's a full stack trace attached)

I don't know what could possibly be wrong with this, and I've tried adding each entry to a List<Condition> and returning that instead, but it still crashes. It works fine if I go to the same {url}/Condition and get all the conditions (they're returned normally), but the client is failing with that weird error. Do I need to use some parser or add some setting to exclude recursive results? The Conditions on my test server are very simple objects with minimal data in them.

Thanks!

  - JK Accetta

[Jean-Karlo Accetta]

I figured it out after a while, though I don't know if this is the best way? Anyway, posting in case anyone else is trying to return the results from their own endpoints:

As mentioned on the first post, I'm using Spring's @RestController and @GetMapping annotations, but I was returning the raw bundle; what fixed it for me was to encode the bundle to a String using the IParser methods:

@GetMapping(value = {"/condition/", "/condition"}, produces = "application/json")
public Object getAll() {
    Bundle bundle = properties.getFhirContext().newRestfulGenericClient(url)
        .search()
        .forResource(Condition.class)
        .returnBundle(Bundle.class)
        .execute()
 
    return properties.getFhirContext().newJsonParser().encodeResourceToString(bundle);
}

Best regards,

   - JK

[bell....@gmail.com]

Thank you very much. I had the same issue and this solved it for me!