Java tutorial
package ca.uhn.fhir.rest.method; /* * #%L * HAPI FHIR - Core Library * %% * Copyright (C) 2014 - 2016 University Health Network * %% * 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% */ import static org.apache.commons.lang3.StringUtils.isNotBlank; import java.lang.reflect.Method; import java.util.Collection; import java.util.Collections; import java.util.HashSet; import java.util.List; import java.util.Map; import java.util.Set; import java.util.StringTokenizer; import org.apache.commons.lang3.StringUtils; import org.hl7.fhir.instance.model.api.IBaseResource; import ca.uhn.fhir.context.ConfigurationException; import ca.uhn.fhir.context.FhirContext; import ca.uhn.fhir.rest.api.SummaryEnum; import ca.uhn.fhir.rest.param.CollectionBinder; import ca.uhn.fhir.rest.server.Constants; import ca.uhn.fhir.rest.server.exceptions.InternalErrorException; import ca.uhn.fhir.rest.server.exceptions.InvalidRequestException; public class ElementsParameter implements IParameter { @SuppressWarnings("rawtypes") private Class<? extends Collection> myInnerCollectionType; @SuppressWarnings("unchecked") @Override public void translateClientArgumentIntoQueryArgument(FhirContext theContext, Object theSourceClientArgument, Map<String, List<String>> theTargetQueryArguments, IBaseResource theTargetResource) throws InternalErrorException { if (theSourceClientArgument instanceof Collection) { StringBuilder values = new StringBuilder(); for (String next : (Collection<String>) theSourceClientArgument) { if (isNotBlank(next)) { if (values.length() > 0) { values.append(','); } values.append(next); } } theTargetQueryArguments.put(Constants.PARAM_ELEMENTS, Collections.singletonList(values.toString())); } else { String elements = (String) theSourceClientArgument; if (elements != null) { theTargetQueryArguments.put(Constants.PARAM_ELEMENTS, Collections.singletonList(elements)); } } } @Override @SuppressWarnings({ "rawtypes", "unchecked" }) public Object translateQueryParametersIntoServerArgument(RequestDetails theRequest, BaseMethodBinding<?> theMethodBinding) throws InternalErrorException, InvalidRequestException { Set<String> value = getElementsValueOrNull(theRequest); if (value == null || value.isEmpty()) { return null; } if (myInnerCollectionType == null) { return StringUtils.join(value, ','); } try { Collection retVal = myInnerCollectionType.newInstance(); retVal.addAll(value); return retVal; } catch (InstantiationException e) { throw new InternalErrorException("Failed to instantiate " + myInnerCollectionType, e); } catch (IllegalAccessException e) { throw new InternalErrorException("Failed to instantiate " + myInnerCollectionType, e); } } public static Set<String> getElementsValueOrNull(RequestDetails theRequest) { String[] summary = theRequest.getParameters().get(Constants.PARAM_ELEMENTS); if (summary != null && summary.length > 0) { Set<String> retVal = new HashSet<String>(); for (String next : summary) { StringTokenizer tok = new StringTokenizer(next, ","); while (tok.hasMoreTokens()) { String token = tok.nextToken(); if (isNotBlank(token)) { retVal.add(token); } } } if (retVal.isEmpty()) { return null; } // Always include the meta element even for subsetted values retVal.add("meta"); return retVal; } else { return null; } } @Override public void initializeTypes(Method theMethod, Class<? extends Collection<?>> theOuterCollectionType, Class<? extends Collection<?>> theInnerCollectionType, Class<?> theParameterType) { if (theOuterCollectionType != null) { throw new ConfigurationException("Method '" + theMethod.getName() + "' in type '" + theMethod.getDeclaringClass().getCanonicalName() + "' is of type " + SummaryEnum.class + " but can not be a collection of collections"); } if (theInnerCollectionType != null) { myInnerCollectionType = CollectionBinder.getInstantiableCollectionType(theInnerCollectionType, SummaryEnum.class.getSimpleName()); } } }