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.sns; import java.io.ByteArrayOutputStream; import java.nio.charset.Charset; import java.util.Arrays; import java.util.Collections; import java.util.List; import java.util.Map; import org.apache.commons.lang3.StringUtils; 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.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 org.apache.nifi.processors.aws.sqs.GetSQS; import org.apache.nifi.processors.aws.sqs.PutSQS; import com.amazonaws.services.sns.AmazonSNSClient; import com.amazonaws.services.sns.model.MessageAttributeValue; import com.amazonaws.services.sns.model.PublishRequest; @SupportsBatching @SeeAlso({ GetSQS.class, PutSQS.class }) @InputRequirement(Requirement.INPUT_REQUIRED) @Tags({ "amazon", "aws", "sns", "topic", "put", "publish", "pubsub" }) @CapabilityDescription("Sends the content of a FlowFile as a notification to the Amazon Simple Notification Service") public class PutSNS extends AbstractSNSProcessor { public static final PropertyDescriptor CHARACTER_ENCODING = new PropertyDescriptor.Builder() .name("Character Set").description("The character set in which the FlowFile's content is encoded") .defaultValue("UTF-8").expressionLanguageSupported(true) .addValidator(StandardValidators.CHARACTER_SET_VALIDATOR).required(true).build(); public static final PropertyDescriptor USE_JSON_STRUCTURE = new PropertyDescriptor.Builder() .name("Use JSON Structure") .description( "If true, the contents of the FlowFile must be JSON with a top-level element named 'default'." + " Additional elements can be used to send different messages to different protocols. See the Amazon" + " SNS Documentation for more information.") .defaultValue("false").allowableValues("true", "false").required(true).build(); public static final PropertyDescriptor SUBJECT = new PropertyDescriptor.Builder().name("E-mail Subject") .description("The optional subject to use for any subscribers that are subscribed via E-mail") .expressionLanguageSupported(true).required(false).addValidator(StandardValidators.NON_EMPTY_VALIDATOR) .build(); public static final List<PropertyDescriptor> properties = Collections.unmodifiableList(Arrays.asList(ARN, ARN_TYPE, SUBJECT, REGION, ACCESS_KEY, SECRET_KEY, CREDENTIALS_FILE, AWS_CREDENTIALS_PROVIDER_SERVICE, TIMEOUT, USE_JSON_STRUCTURE, CHARACTER_ENCODING, PROXY_HOST, PROXY_HOST_PORT)); public static final int MAX_SIZE = 256 * 1024; @Override protected List<PropertyDescriptor> getSupportedPropertyDescriptors() { return properties; } @Override protected PropertyDescriptor getSupportedDynamicPropertyDescriptor(final String propertyDescriptorName) { return new PropertyDescriptor.Builder().name(propertyDescriptorName) .addValidator(StandardValidators.NON_EMPTY_VALIDATOR).expressionLanguageSupported(true) .required(false).dynamic(true).build(); } @Override public void onTrigger(final ProcessContext context, final ProcessSession session) { FlowFile flowFile = session.get(); if (flowFile == null) { return; } if (flowFile.getSize() > MAX_SIZE) { getLogger().error( "Cannot publish {} to SNS because its size exceeds Amazon SNS's limit of 256KB; routing to failure", new Object[] { flowFile }); session.transfer(flowFile, REL_FAILURE); return; } final Charset charset = Charset .forName(context.getProperty(CHARACTER_ENCODING).evaluateAttributeExpressions(flowFile).getValue()); final ByteArrayOutputStream baos = new ByteArrayOutputStream(); session.exportTo(flowFile, baos); final String message = new String(baos.toByteArray(), charset); final AmazonSNSClient client = getClient(); final PublishRequest request = new PublishRequest(); request.setMessage(message); if (context.getProperty(USE_JSON_STRUCTURE).asBoolean()) { request.setMessageStructure("json"); } final String arn = context.getProperty(ARN).evaluateAttributeExpressions(flowFile).getValue(); final String arnType = context.getProperty(ARN_TYPE).getValue(); if (arnType.equalsIgnoreCase(ARN_TYPE_TOPIC.getValue())) { request.setTopicArn(arn); } else { request.setTargetArn(arn); } final String subject = context.getProperty(SUBJECT).evaluateAttributeExpressions(flowFile).getValue(); if (subject != null) { request.setSubject(subject); } for (final Map.Entry<PropertyDescriptor, String> entry : context.getProperties().entrySet()) { if (entry.getKey().isDynamic() && !StringUtils.isEmpty(entry.getValue())) { final MessageAttributeValue value = new MessageAttributeValue(); value.setStringValue( context.getProperty(entry.getKey()).evaluateAttributeExpressions(flowFile).getValue()); value.setDataType("String"); request.addMessageAttributesEntry(entry.getKey().getName(), value); } } try { client.publish(request); session.transfer(flowFile, REL_SUCCESS); session.getProvenanceReporter().send(flowFile, arn); getLogger().info("Successfully published notification for {}", new Object[] { flowFile }); } catch (final Exception e) { getLogger().error("Failed to publish Amazon SNS message for {} due to {}", new Object[] { flowFile, e }); flowFile = session.penalize(flowFile); session.transfer(flowFile, REL_FAILURE); } } }