Java tutorial
/* * 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.aws.sqs; import java.io.ByteArrayOutputStream; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.HashMap; import java.util.HashSet; import java.util.List; import java.util.Map; import java.util.Set; import java.util.concurrent.TimeUnit; import org.apache.nifi.annotation.behavior.DynamicProperty; import org.apache.nifi.annotation.behavior.InputRequirement; import org.apache.nifi.annotation.behavior.InputRequirement.Requirement; import org.apache.nifi.annotation.behavior.SupportsBatching; 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.annotation.lifecycle.OnScheduled; import org.apache.nifi.components.PropertyDescriptor; import org.apache.nifi.flowfile.FlowFile; import org.apache.nifi.processor.ProcessContext; import org.apache.nifi.processor.ProcessSession; import org.apache.nifi.processor.util.StandardValidators; import com.amazonaws.services.sqs.AmazonSQSClient; import com.amazonaws.services.sqs.model.MessageAttributeValue; import com.amazonaws.services.sqs.model.SendMessageBatchRequest; import com.amazonaws.services.sqs.model.SendMessageBatchRequestEntry; @SupportsBatching @SeeAlso({ GetSQS.class, DeleteSQS.class }) @InputRequirement(Requirement.INPUT_REQUIRED) @Tags({ "Amazon", "AWS", "SQS", "Queue", "Put", "Publish" }) @CapabilityDescription("Publishes a message to an Amazon Simple Queuing Service Queue") @DynamicProperty(name = "The name of a Message Attribute to add to the message", value = "The value of the Message Attribute", description = "Allows the user to add key/value pairs as Message Attributes by adding a property whose name will become the name of " + "the Message Attribute and value will become the value of the Message Attribute", supportsExpressionLanguage = true) public class PutSQS extends AbstractSQSProcessor { public static final PropertyDescriptor DELAY = new PropertyDescriptor.Builder().name("Delay") .description("The amount of time to delay the message before it becomes available to consumers") .required(true).addValidator(StandardValidators.TIME_PERIOD_VALIDATOR).defaultValue("0 secs").build(); public static final List<PropertyDescriptor> properties = Collections .unmodifiableList(Arrays.asList(QUEUE_URL, ACCESS_KEY, SECRET_KEY, CREDENTIALS_FILE, AWS_CREDENTIALS_PROVIDER_SERVICE, REGION, DELAY, TIMEOUT, PROXY_HOST, PROXY_HOST_PORT)); private volatile List<PropertyDescriptor> userDefinedProperties = Collections.emptyList(); @Override protected List<PropertyDescriptor> getSupportedPropertyDescriptors() { return properties; } @Override protected PropertyDescriptor getSupportedDynamicPropertyDescriptor(final String propertyDescriptorName) { return new PropertyDescriptor.Builder().name(propertyDescriptorName).expressionLanguageSupported(true) .required(false).dynamic(true).addValidator(StandardValidators.NON_EMPTY_VALIDATOR).build(); } @OnScheduled public void setup(final ProcessContext context) { userDefinedProperties = new ArrayList<>(); for (final PropertyDescriptor descriptor : context.getProperties().keySet()) { if (descriptor.isDynamic()) { userDefinedProperties.add(descriptor); } } } @Override public void onTrigger(final ProcessContext context, final ProcessSession session) { FlowFile flowFile = session.get(); if (flowFile == null) { return; } final long startNanos = System.nanoTime(); final AmazonSQSClient client = getClient(); final SendMessageBatchRequest request = new SendMessageBatchRequest(); final String queueUrl = context.getProperty(QUEUE_URL).evaluateAttributeExpressions(flowFile).getValue(); request.setQueueUrl(queueUrl); final Set<SendMessageBatchRequestEntry> entries = new HashSet<>(); final SendMessageBatchRequestEntry entry = new SendMessageBatchRequestEntry(); entry.setId(flowFile.getAttribute("uuid")); final ByteArrayOutputStream baos = new ByteArrayOutputStream(); session.exportTo(flowFile, baos); final String flowFileContent = baos.toString(); entry.setMessageBody(flowFileContent); final Map<String, MessageAttributeValue> messageAttributes = new HashMap<>(); for (final PropertyDescriptor descriptor : userDefinedProperties) { final MessageAttributeValue mav = new MessageAttributeValue(); mav.setDataType("String"); mav.setStringValue(context.getProperty(descriptor).evaluateAttributeExpressions(flowFile).getValue()); messageAttributes.put(descriptor.getName(), mav); } entry.setMessageAttributes(messageAttributes); entry.setDelaySeconds(context.getProperty(DELAY).asTimePeriod(TimeUnit.SECONDS).intValue()); entries.add(entry); request.setEntries(entries); try { client.sendMessageBatch(request); } catch (final Exception e) { getLogger().error("Failed to send messages to Amazon SQS due to {}; routing to failure", new Object[] { e }); flowFile = session.penalize(flowFile); session.transfer(flowFile, REL_FAILURE); return; } getLogger().info("Successfully published message to Amazon SQS for {}", new Object[] { flowFile }); session.transfer(flowFile, REL_SUCCESS); final long transmissionMillis = TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - startNanos); session.getProvenanceReporter().send(flowFile, queueUrl, transmissionMillis); } }