Adding class shadowing for issue reported on hapifhir/hapi-fhir#7242

Author: jkiddo

src/main/java/ca/uhn/fhir/jpa/provider/BaseJpaResourceProviderObservation.java

@@ -0,0 +1,107 @@
+/*
+ * #%L
+ * HAPI FHIR JPA Server
+ * %%
+ * Copyright (C) 2014 - 2025 Smile CDR, Inc.
+ * %%
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * #L%
+ */
+package ca.uhn.fhir.jpa.provider;
+
+import ca.uhn.fhir.jpa.api.dao.IFhirResourceDaoObservation;
+import ca.uhn.fhir.jpa.model.util.JpaConstants;
+import ca.uhn.fhir.jpa.searchparam.SearchParameterMap;
+import ca.uhn.fhir.model.api.annotation.Description;
+import ca.uhn.fhir.model.valueset.BundleTypeEnum;
+import ca.uhn.fhir.rest.annotation.Operation;
+import ca.uhn.fhir.rest.annotation.OperationParam;
+import ca.uhn.fhir.rest.annotation.RawParam;
+import ca.uhn.fhir.rest.api.Constants;
+import ca.uhn.fhir.rest.api.server.IBundleProvider;
+import ca.uhn.fhir.rest.param.DateAndListParam;
+import ca.uhn.fhir.rest.param.ReferenceAndListParam;
+import ca.uhn.fhir.rest.param.TokenAndListParam;
+import org.hl7.fhir.instance.model.api.IBaseResource;
+import org.hl7.fhir.instance.model.api.IPrimitiveType;
+
+import java.util.List;
+import java.util.Map;
+
+public abstract class BaseJpaResourceProviderObservation<T extends IBaseResource> extends BaseJpaResourceProvider<T> {
+
+	/**
+	 * Observation/$lastn
+	 */
+	@Operation(name = JpaConstants.OPERATION_LASTN, idempotent = true, bundleType = BundleTypeEnum.SEARCHSET)
+	public IBundleProvider observationLastN(
+			jakarta.servlet.http.HttpServletRequest theServletRequest,
+			jakarta.servlet.http.HttpServletResponse theServletResponse,
+			ca.uhn.fhir.rest.api.server.RequestDetails theRequestDetails,
+			@Description(
+							formalDefinition =
+									"Results from this method are returned across multiple pages. This parameter controls the size of those pages.")
+					@OperationParam(name = Constants.PARAM_COUNT, typeName = "unsignedInt")
+					IPrimitiveType<Integer> theCount,
+			@Description(shortDefinition = "The classification of the type of observation")
+					@OperationParam(name = "category")
+					TokenAndListParam theCategory,
+			@Description(shortDefinition = "The code of the observation type") @OperationParam(name = "code")
+					TokenAndListParam theCode,
+			@Description(shortDefinition = "The effective date of the observation") @OperationParam(name = "date")
+					DateAndListParam theDate,
+			@Description(shortDefinition = "The subject that the observation is about (if patient)")
+					@OperationParam(name = "patient")
+					ReferenceAndListParam thePatient,
+			@Description(shortDefinition = "The subject that the observation is about")
+					@OperationParam(name = "subject")
+					ReferenceAndListParam theSubject,
+			@Description(shortDefinition = "The maximum number of observations to return for each observation code")
+					@OperationParam(name = "max", typeName = "integer", min = 0, max = 1)
+					IPrimitiveType<Integer> theMax,
+			@RawParam Map<String, List<String>> theAdditionalRawParams) {
+		startRequest(theServletRequest);
+		try {
+			SearchParameterMap paramMap = new SearchParameterMap();
+			paramMap.add(org.hl7.fhir.r4.model.Observation.SP_CATEGORY, theCategory);
+			paramMap.add(org.hl7.fhir.r4.model.Observation.SP_CODE, theCode);
+			paramMap.add(org.hl7.fhir.r4.model.Observation.SP_DATE, theDate);
+			if (thePatient != null) {
+				paramMap.add(org.hl7.fhir.r4.model.Observation.SP_PATIENT, thePatient);
+			}
+			if (theSubject != null) {
+				paramMap.add(org.hl7.fhir.r4.model.Observation.SP_SUBJECT, theSubject);
+			}
+			if (theMax != null) {
+				paramMap.setLastNMax(theMax.getValue());
+
+				/**
+				 * The removal of the original raw parameter is required as every implementing class
+				 * has the "Observation" resource class defined. For this resource, the max parameter
+				 * is not supported and thus has to be removed before the use of "translateRawParameters".
+				 */
+				if (theAdditionalRawParams != null) theAdditionalRawParams.remove("max");
+			}
+			if (theCount != null) {
+				paramMap.setCount(theCount.getValue());
+			}
+
+			getDao().translateRawParameters(theAdditionalRawParams, paramMap);
+
+			return ((IFhirResourceDaoObservation<?>) getDao())
+					.observationsLastN(paramMap, theRequestDetails, theServletResponse);
+		} finally {
+			endRequest(theServletRequest);
+		}
+	}
+}