HAPI FHIR JPA Server Notes

I have registered hook methods for seven server cutpoints and none is called. I have written about 7 hook methods, one for each of most of the server pointcuts.

From IntelliJ IDEA's project pane, I right click on ExampleServerR4IT.main() and Debug it. I have already added the lines highlighted below in order to force the JUnit test to reveal what port IDEA is really running the server on:

ExampleServerR4IT.java:

public class ExampleServerR4IT {
    ...
    private static String ourServerBase;  // my new static to reveal port we're running on
    ...
    @BeforeClass
    public static void beforeClass() throws Exception {
        ...
        ourServerBase = "http://localhost:" + ourPort + "/hapi-fhir-jpaserver/fhir/";
        ...
    }

    public static void main(String[] theArgs) throws Exception {
        ourPort = 7070;
        beforeClass();
        ourLog.info("Server base is: " + ourServerBase);
    }

...which I caused to be set in @BeforeClass in order to know what the URL to hit from Postman will be. I have breakpoints set inside every hook method.

Then, using that URL (with the port number that will change each time I relaunch the debugger on the test), I get </> RESTED to POST in a few names which I can see when I do a GET http://localhost:33945/hapi-fhir-jpaserver/fhir/Patient?_limit=10

At no time is any of my breakpoints hit despite that I have, I think, reached and passed points like SERVER_INCOMING_REQUEST_PRE_PROCESSED, SERVER_INCOMING_REQUEST_POST_PROCESSED, SERVER_OUTGOING_RESPONSE, etc.

Is there something else, beyond mere annotations, that I need to do to get the rest of the (cloned and as yet unmodified) code to register my callbacks? I did try toggling the following booleans in hapi.properties to true:

Interceptor/Hook source code

I have created the following files on the path hapi-fhir-jpaserver-starter/src/main/java/com/windofkeltia/fhir/server. This package is inside the server code, parallel to hapi-fhir-jpaserver-starter/src/main/java/ca/uhn/fhir/jpa/starter. I assume, perhaps wrongly, that this code—by virtue of the @Hook annotation (the @Interceptor annotation is optional, so must not do anything), should build into the server.

I launch for debugging inside IDEA the main() method of ExampleServerR4IT.java, having doctored that method to give me the actual port number IntelliJ IDEA runs it on (we're no longer using the server we tried out on the command line). I have already shown that code above. Then, using </> RESTED, I try POSTing a new patient, GETing a patient, etc., but never are the breakpoints hit.

RequestCounterInterceptor.java:

This example comes directly from the documentation. The debugger I set at line 20 is never hit.

package com.windofkeltia.fhir.server;

import ca.uhn.fhir.interceptor.api.Hook;
import ca.uhn.fhir.interceptor.api.Interceptor;
import ca.uhn.fhir.interceptor.api.Pointcut;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@Interceptor
public class RequestCounterInterceptor
{
  private int requestCount;

  public int getRequestCount() { return requestCount; }

  @Hook( Pointcut.SERVER_INCOMING_REQUEST_PRE_PROCESSED )
  public boolean incomingRequestPreprocessed( HttpServletRequest request, HttpServletResponse response )
  {
    requestCount++;
    return true;
  }
}

Interceptors.java:

These are most if not all of the pointcuts I wish to investigate for my use. Of course, I never hit breakpoints I set on these lines.

package com.windofkeltia.fhir.server;

import ca.uhn.fhir.interceptor.api.Hook;
import ca.uhn.fhir.interceptor.api.Interceptor;
import ca.uhn.fhir.interceptor.api.Pointcut;
import ca.uhn.fhir.rest.api.server.RequestDetails;
import ca.uhn.fhir.rest.server.exceptions.BaseServerResponseException;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Interceptor
public class Interceptors
{
  private int requestCount;
  private int responseCount;

  public int getRequestCount() { return requestCount; }
  public int getResponseCount() { return responseCount; }

  @Hook( Pointcut.SERVER_INCOMING_REQUEST_PRE_PROCESSED )
  public boolean incomingRequestPreprocessed( HttpServletRequest request, HttpServletResponse response )
  {
    requestCount++;
    return true;
  }

  @Hook( Pointcut.SERVER_INCOMING_REQUEST_POST_PROCESSED )
  public boolean incomingRequestPostprocessed( HttpServletRequest request, HttpServletResponse response )
  {
    requestCount++;
    return true;
  }

  @Hook( Pointcut.SERVER_INCOMING_REQUEST_PRE_HANDLED )
  public boolean incomingRequestPrehandled( HttpServletRequest request )
  {
    requestCount++;
    return true;
  }

  @Hook( Pointcut.SERVER_OUTGOING_RESPONSE )
  public boolean outgoingResponsePrepared( HttpServletResponse response )
  {
    responseCount++;
    return true;
  }

  @Hook( Pointcut.SERVER_PROCESSING_COMPLETED_NORMALLY )
  public boolean outgoingResponseSerialized( HttpServletResponse response )
  {
    responseCount++;
    return true;
  }

  @Hook( Pointcut.SERVER_PROCESSING_COMPLETED )
  public boolean outgoingResponseToClient( HttpServletResponse response )
  {
    responseCount++;
    return true;
  }

  @Hook( Pointcut.SERVER_HANDLE_EXCEPTION )
  public boolean handleException( RequestDetails details, BaseServerResponseException exception,
                                    HttpServletRequest request, HttpServletResponse response )
    throws IOException
  {
    response.setStatus( exception.getStatusCode() );
    response.setContentType( "text/plain" );
    response.getWriter().append( "Failed to process" );
    response.getWriter().close();
    return false;
  }
}

HAPI FHIR JPA Server Notes

Relevant links

Cloning the project from GitHub

This project is actively developed...

Setting up the project in IntelliJ IDEA

Demonstration of using the server

Intercepting execution in the server...

Terminology

ExampleServerR4IT.java:

Interceptor/Hook source code

RequestCounterInterceptor.java:

Interceptors.java:

Lucene lock held by Hibernate...