mh013370 commented on code in PR #7760: URL: https://github.com/apache/nifi/pull/7760#discussion_r1331089560
########## nifi-nar-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/processors/standard/PackageFlowFile.java: ########## @@ -0,0 +1,146 @@ +/* + * 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.standard; + +import org.apache.nifi.annotation.behavior.InputRequirement; +import org.apache.nifi.annotation.behavior.SideEffectFree; +import org.apache.nifi.annotation.behavior.SupportsBatching; +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.flowfile.FlowFile; +import org.apache.nifi.flowfile.attributes.CoreAttributes; +import org.apache.nifi.flowfile.attributes.StandardFlowFileMediaType; +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.processor.util.StandardValidators; +import org.apache.nifi.util.FlowFilePackager; +import org.apache.nifi.util.FlowFilePackagerV3; + +import java.io.BufferedInputStream; +import java.io.BufferedOutputStream; +import java.io.InputStream; +import java.io.OutputStream; +import java.util.Arrays; +import java.util.Collections; +import java.util.HashMap; +import java.util.LinkedHashSet; +import java.util.List; +import java.util.Map; +import java.util.Set; + + +@SideEffectFree +@SupportsBatching +@InputRequirement(InputRequirement.Requirement.INPUT_REQUIRED) +@Tags({"flowfile", "flowfile-stream", "flowfile-stream-v3", "package", "attributes"}) +@CapabilityDescription("This processor will package FlowFile attributes and content into an output FlowFile that can be exported from NiFi" + + " and imported back into NiFi, preserving the original attributes and content.") +@WritesAttributes({ + @WritesAttribute(attribute = "mime.type", description = "The mime.type will be changed to application/flowfile-v3"), + @WritesAttribute(attribute = "filename", description = "The filename will be appended with '.pkg'") +}) +@SeeAlso({UnpackContent.class, MergeContent.class}) +public class PackageFlowFile extends AbstractProcessor { + + static final String PACKAGE_FILENAME_EXTENSION = ".pkg"; + + public static final PropertyDescriptor BATCH_SIZE = new PropertyDescriptor.Builder() + .name("max-batch-size") + .displayName("Maximum Batch Size") + .description("Maximum number of FlowFiles to package into one output FlowFile using a best effort, non guaranteed approach." + + " Multiple input queues can produce unexpected batching behavior.") + .required(true) + .defaultValue("1") + .addValidator(StandardValidators.createLongValidator(1, 10_000, true)) + .build(); + + static final Relationship REL_SUCCESS = new Relationship.Builder() + .name("success") + .description("The packaged FlowFile is sent to this relationship") + .build(); + static final Relationship REL_ORIGINAL = new Relationship.Builder() + .name("original") + .description("The FlowFiles that were used to create the package are sent to this relationship") + .build(); + + private static final Set<Relationship> RELATIONSHIPS = Collections.unmodifiableSet( + new LinkedHashSet<>(Arrays.asList( + REL_SUCCESS, + REL_ORIGINAL + ))); + + private static final List<PropertyDescriptor> PROPERTY_DESCRIPTORS = Collections.unmodifiableList( + Arrays.asList( + BATCH_SIZE + )); + + @Override + public Set<Relationship> getRelationships() { + return RELATIONSHIPS; + } + + @Override + protected List<PropertyDescriptor> getSupportedPropertyDescriptors() { + return PROPERTY_DESCRIPTORS; + } + + @Override + public void onTrigger(ProcessContext context, ProcessSession session) throws ProcessException { + final List<FlowFile> flowFiles = session.get(context.getProperty(BATCH_SIZE).asInteger()); + if (flowFiles.isEmpty()) { + return; + } + + final Map<String, String> attributes = new HashMap<>(); + attributes.put(CoreAttributes.MIME_TYPE.key(), StandardFlowFileMediaType.VERSION_3.getMediaType()); + attributes.put(CoreAttributes.FILENAME.key(), createFilename(flowFiles)); + + final FlowFilePackager packager = new FlowFilePackagerV3(); + + FlowFile packagedFlowFile = session.create(flowFiles); + packagedFlowFile = session.write(packagedFlowFile, out -> { + try (final OutputStream bufferedOut = new BufferedOutputStream(out)) { + for (final FlowFile flowFile : flowFiles) { + session.read(flowFile, in -> { + try (final InputStream bufferedIn = new BufferedInputStream(in)) { + packager.packageFlowFile(bufferedIn, bufferedOut, flowFile.getAttributes(), flowFile.getSize()); + } + }); + } + } + }); + + packagedFlowFile = session.putAllAttributes(packagedFlowFile, attributes); + session.transfer(packagedFlowFile, REL_SUCCESS); + session.transfer(flowFiles, REL_ORIGINAL); + } + + private String createFilename(final List<FlowFile> flowFiles) { Review Comment: Do you think users would prefer more positive control over the name of the output filename, perhaps via an attribute? -- This is an automated message from the Apache Git Service. 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