exceptionfactory commented on code in PR #7458: URL: https://github.com/apache/nifi/pull/7458#discussion_r1263767571
########## nifi-nar-bundles/nifi-extension-utils/nifi-resource-transfer/src/main/java/org/apache/nifi/processors/transfer/ResourceTransferUtils.java: ########## @@ -0,0 +1,85 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You 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. + */ +package org.apache.nifi.processors.transfer; + +import org.apache.nifi.components.PropertyValue; +import org.apache.nifi.fileresource.service.api.FileResource; +import org.apache.nifi.fileresource.service.api.FileResourceService; +import org.apache.nifi.flowfile.FlowFile; +import org.apache.nifi.processor.ProcessContext; +import org.apache.nifi.processor.ProcessSession; +import org.apache.nifi.processor.exception.ProcessException; + +import java.io.InputStream; +import java.util.Optional; + +import static org.apache.nifi.processors.transfer.ResourceTransferProperties.FILE_RESOURCE_SERVICE; + +public final class ResourceTransferUtils { + + private ResourceTransferUtils() {} + + /** + * Get File Resource from File Resource Service based on provided Source otherwise return empty + * + * @param resourceTransferSource type of the data upload + * @param context process context with properties + * @param flowFile FlowFile with attributes to use in expression language + * @return Optional FileResource retrieved from FileResourceService if Source is File Resource Service, otherwise empty + * @throws ProcessException Thrown if Source is File Resource but FileResourceService is not provided in the context + */ + public static Optional<FileResource> getFileResource(final ResourceTransferSource resourceTransferSource, final ProcessContext context, final FlowFile flowFile) { + final Optional<FileResource> resource; + + if (resourceTransferSource == ResourceTransferSource.FILE_RESOURCE_SERVICE) { + final PropertyValue property = context.getProperty(FILE_RESOURCE_SERVICE); + if (property == null || !property.isSet()) { + throw new ProcessException("File Resource Service required but not configured"); + } + final FileResourceService fileResourceService = property.asControllerService(FileResourceService.class); + final FileResource fileResource = fileResourceService.getFileResource(flowFile.getAttributes()); + resource = Optional.ofNullable(fileResource); + } else { + resource = Optional.empty(); + } + + return resource; + } + + /** + * Returns the input stream of the FileResource if it is provided (not null). Otherwise, returns the input stream of the FlowFile. + * + * @param session the session to read the FlowFile + * @param flowFile the FlowFile which is read when no FileResource is provided + * @param fileResource the FileResource + * @return input stream of the FileResource or the FlowFile + */ + public static InputStream getTransferInputStream(final ProcessSession session, final FlowFile flowFile, final FileResource fileResource) { Review Comment: I attempted to minimize changes, but with the adjustment to return `Optional<FileResource>`, this particular method probably needs to be adjusted. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@nifi.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
