001/*-
002 * #%L
003 * HAPI FHIR - Server Framework
004 * %%
005 * Copyright (C) 2014 - 2024 Smile CDR, Inc.
006 * %%
007 * Licensed under the Apache License, Version 2.0 (the "License");
008 * you may not use this file except in compliance with the License.
009 * You may obtain a copy of the License at
010 *
011 *      http://www.apache.org/licenses/LICENSE-2.0
012 *
013 * Unless required by applicable law or agreed to in writing, software
014 * distributed under the License is distributed on an "AS IS" BASIS,
015 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
016 * See the License for the specific language governing permissions and
017 * limitations under the License.
018 * #L%
019 */
020package ca.uhn.fhir.rest.server.interceptor;
021
022import ca.uhn.fhir.context.FhirContext;
023import ca.uhn.fhir.interceptor.api.Hook;
024import ca.uhn.fhir.interceptor.api.Interceptor;
025import ca.uhn.fhir.interceptor.api.Pointcut;
026import ca.uhn.fhir.rest.api.EncodingEnum;
027import ca.uhn.fhir.rest.api.server.RequestDetails;
028import ca.uhn.fhir.util.ClasspathUtil;
029import org.apache.commons.lang3.Validate;
030import org.hl7.fhir.instance.model.api.IBaseConformance;
031
032/**
033 * This interceptor replaces the auto-generated CapabilityStatement that is generated
034 * by the HAPI FHIR Server with a static hard-coded resource.
035 */
036@Interceptor
037public class StaticCapabilityStatementInterceptor {
038
039        private String myCapabilityStatementResource;
040        private volatile IBaseConformance myCapabilityStatement;
041
042        /**
043         * Sets the CapabilityStatement to use
044         *
045         * @see #setCapabilityStatementResource(String) #setCapabilityStatementResource(String) is an alternate way to supply the CapabilityStatement
046         */
047        public void setCapabilityStatement(IBaseConformance theCapabilityStatement) {
048                myCapabilityStatement = theCapabilityStatement;
049        }
050
051        /**
052         * Sets the classpath location of the CapabilityStatement to use. If this method is used to supply
053         * the CapabiltyStatement, then the given classpath resource will be read and parsed as a FHIR
054         * CapabilityStatement.
055         *
056         * @see #setCapabilityStatement(IBaseConformance) #setCapabilityStatement(IBaseConformance) is an alternate way to supply the CapabilityStatement
057         */
058        public void setCapabilityStatementResource(String theClasspath) {
059                myCapabilityStatementResource = theClasspath;
060                myCapabilityStatement = null;
061        }
062
063        @Hook(Pointcut.SERVER_CAPABILITY_STATEMENT_GENERATED)
064        public IBaseConformance hook(RequestDetails theRequestDetails) {
065                IBaseConformance retVal = myCapabilityStatement;
066
067                if (retVal == null) {
068                        Validate.notBlank(myCapabilityStatementResource, "No CapabilityStatement defined");
069                        String output = ClasspathUtil.loadResource(myCapabilityStatementResource);
070
071                        FhirContext ctx = theRequestDetails.getFhirContext();
072                        EncodingEnum encoding = EncodingEnum.detectEncodingNoDefault(output);
073                        Validate.notNull(
074                                        encoding, "Could not determine FHIR encoding for resource: %s", myCapabilityStatementResource);
075
076                        retVal = (IBaseConformance) encoding.newParser(ctx).parseResource(output);
077                        myCapabilityStatement = retVal;
078                }
079
080                return retVal;
081        }
082}