001/*
002 * #%L
003 * HAPI FHIR JPA Server
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.jpa.util.xmlpatch;
021
022import ca.uhn.fhir.context.FhirContext;
023import ca.uhn.fhir.i18n.Msg;
024import ca.uhn.fhir.rest.api.Constants;
025import ca.uhn.fhir.rest.server.exceptions.InternalErrorException;
026import com.github.dnault.xmlpatch.Patcher;
027import org.hl7.fhir.instance.model.api.IBaseResource;
028
029import java.io.ByteArrayInputStream;
030import java.io.ByteArrayOutputStream;
031import java.io.IOException;
032
033public class XmlPatchUtils {
034
035        public static <T extends IBaseResource> T apply(FhirContext theCtx, T theResourceToUpdate, String thePatchBody) {
036
037                @SuppressWarnings("unchecked")
038                Class<T> clazz = (Class<T>) theResourceToUpdate.getClass();
039
040                String inputResource = theCtx.newXmlParser().encodeResourceToString(theResourceToUpdate);
041
042                ByteArrayOutputStream result = new ByteArrayOutputStream();
043                try {
044                        Patcher.patch(
045                                        new ByteArrayInputStream(inputResource.getBytes(Constants.CHARSET_UTF8)),
046                                        new ByteArrayInputStream(thePatchBody.getBytes(Constants.CHARSET_UTF8)),
047                                        result);
048                } catch (IOException e) {
049                        throw new InternalErrorException(Msg.code(817) + e);
050                }
051
052                String resultString = new String(result.toByteArray(), Constants.CHARSET_UTF8);
053                T retVal = theCtx.newXmlParser().parseResource(clazz, resultString);
054
055                return retVal;
056        }
057}