turcsanyip commented on code in PR #6279: URL: https://github.com/apache/nifi/pull/6279#discussion_r958157545
########## nifi-nar-bundles/nifi-smb-bundle/nifi-smb-processors/src/main/java/org/apache/nifi/processors/smb/FetchSmb.java: ########## @@ -0,0 +1,153 @@ +/* + * 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.smb; + +import static java.util.Arrays.asList; +import static org.apache.nifi.expression.ExpressionLanguageScope.FLOWFILE_ATTRIBUTES; +import static org.apache.nifi.processor.util.StandardValidators.ATTRIBUTE_EXPRESSION_LANGUAGE_VALIDATOR; + +import java.util.Collections; +import java.util.HashSet; +import java.util.List; +import java.util.Map; +import java.util.Optional; +import java.util.Set; +import org.apache.nifi.annotation.behavior.InputRequirement; +import org.apache.nifi.annotation.behavior.WritesAttribute; +import org.apache.nifi.annotation.behavior.WritesAttributes; +import org.apache.nifi.annotation.documentation.CapabilityDescription; +import org.apache.nifi.annotation.documentation.SeeAlso; +import org.apache.nifi.annotation.documentation.Tags; +import org.apache.nifi.components.PropertyDescriptor; +import org.apache.nifi.components.PropertyDescriptor.Builder; +import org.apache.nifi.flowfile.FlowFile; +import org.apache.nifi.processor.AbstractProcessor; +import org.apache.nifi.processor.ProcessContext; +import org.apache.nifi.processor.ProcessSession; +import org.apache.nifi.processor.Relationship; +import org.apache.nifi.processor.exception.ProcessException; +import org.apache.nifi.services.smb.SmbClientProviderService; +import org.apache.nifi.services.smb.SmbClientService; +import org.apache.nifi.services.smb.SmbException; + +@InputRequirement(InputRequirement.Requirement.INPUT_REQUIRED) +@Tags({"samba, smb, cifs, files", "fetch"}) +@CapabilityDescription("Fetches files from a SMB Share. Designed to be used in tandem with ListSmb.") +@SeeAlso({ListSmb.class, PutSmbFile.class, GetSmbFile.class}) +@WritesAttributes({ + @WritesAttribute(attribute = FetchSmb.ERROR_CODE_ATTRIBUTE, description = "The error code returned by SMB when the fetch of a file fails"), + @WritesAttribute(attribute = FetchSmb.ERROR_MESSAGE_ATTRIBUTE, description = "The error message returned by SMB when the fetch of a file fails") +}) +public class FetchSmb extends AbstractProcessor { + + public static final String ERROR_CODE_ATTRIBUTE = "error.code"; + public static final String ERROR_MESSAGE_ATTRIBUTE = "error.message"; + + public static final PropertyDescriptor REMOTE_FILE = new PropertyDescriptor + .Builder().name("remote-file") + .displayName("Remote File") + .description( + "The full path of the file to be retrieved from the remote server. EL is supported when record reader is not used.") + .required(true) + .expressionLanguageSupported(FLOWFILE_ATTRIBUTES) + .defaultValue("${path}/${filename}") + .addValidator(ATTRIBUTE_EXPRESSION_LANGUAGE_VALIDATOR) + .build(); + + public static final PropertyDescriptor SMB_CLIENT_PROVIDER_SERVICE = new Builder() + .name("smb-client-provider-service") + .displayName("SMB Client Provider Service") + .description("Specifies the SMB client provider to use for creating SMB connections.") + .required(true) + .identifiesControllerService(SmbClientProviderService.class) + .build(); + public static final Relationship REL_SUCCESS = + new Relationship.Builder() + .name("success") + .description("A flowfile will be routed here for each successfully fetched File.") + .build(); + public static final Relationship REL_FAILURE = + new Relationship.Builder().name("failure") + .description( + "A flowfile will be routed here for each File for which fetch was attempted but failed.") + .build(); + public static final Set<Relationship> relationships = Collections.unmodifiableSet(new HashSet<>(asList( + REL_SUCCESS, + REL_FAILURE + ))); + public static final String UNCATEGORIZED_ERROR = "-2"; + private static final List<PropertyDescriptor> PROPERTIES = asList( + SMB_CLIENT_PROVIDER_SERVICE, + REMOTE_FILE + ); + + @Override + public Set<Relationship> getRelationships() { + return relationships; + } + + @Override + public void onTrigger(ProcessContext context, ProcessSession session) throws ProcessException { + FlowFile flowFile = session.get(); + if (flowFile == null) { + return; + } + + final SmbClientProviderService clientProviderService = + context.getProperty(SMB_CLIENT_PROVIDER_SERVICE).asControllerService(SmbClientProviderService.class); + + try (SmbClientService client = clientProviderService.getClient()) { + fetchAndTransfer(session, context, client, flowFile); + } catch (Exception e) { + getLogger().error("Couldn't connect to smb due to " + e.getMessage()); + flowFile = session.putAttribute(flowFile, ERROR_CODE_ATTRIBUTE, getErrorCode(e)); + flowFile = session.putAttribute(flowFile, ERROR_MESSAGE_ATTRIBUTE, e.getMessage()); + session.transfer(flowFile, REL_FAILURE); + } + + } + + @Override + protected List<PropertyDescriptor> getSupportedPropertyDescriptors() { + return PROPERTIES; + } + + private void fetchAndTransfer(ProcessSession session, ProcessContext context, SmbClientService client, + FlowFile flowFile) { + final Map<String, String> attributes = flowFile.getAttributes(); + final String filename = context.getProperty(REMOTE_FILE) + .evaluateAttributeExpressions(attributes).getValue(); + try { + flowFile = session.write(flowFile, outputStream -> client.readFile(filename, outputStream)); + session.transfer(flowFile, REL_SUCCESS); + } catch (Exception e) { + getLogger().error("Couldn't fetch file {} due to {}", filename, e.getMessage()); Review Comment: Update: The following should also work and even more compact: ``` getLogger().error("Could not fetch file {}", filename, e); ``` -- This is an automated message from the Apache Git Service. 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