Github user mans2singh commented on a diff in the pull request: https://github.com/apache/nifi/pull/224#discussion_r54336499 --- Diff: nifi-nar-bundles/nifi-aws-bundle/nifi-aws-processors/src/main/java/org/apache/nifi/processors/aws/dynamodb/GetDynamoDB.java --- @@ -0,0 +1,180 @@ +/* + * 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.dynamodb; + +import java.io.ByteArrayInputStream; +import java.util.Arrays; +import java.util.Collections; +import java.util.HashMap; +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.ReadsAttribute; +import org.apache.nifi.annotation.behavior.ReadsAttributes; +import org.apache.nifi.annotation.behavior.InputRequirement.Requirement; +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.processor.ProcessContext; +import org.apache.nifi.processor.ProcessSession; + +import com.amazonaws.AmazonClientException; +import com.amazonaws.AmazonServiceException; +import com.amazonaws.services.dynamodbv2.document.BatchGetItemOutcome; +import com.amazonaws.services.dynamodbv2.document.DynamoDB; +import com.amazonaws.services.dynamodbv2.document.Item; +import com.amazonaws.services.dynamodbv2.document.TableKeysAndAttributes; +import com.amazonaws.services.dynamodbv2.model.AttributeValue; +import com.amazonaws.services.dynamodbv2.model.KeysAndAttributes; + +@SupportsBatching +@SeeAlso({DeleteDynamoDB.class, PutDynamoDB.class}) +@InputRequirement(Requirement.INPUT_REQUIRED) +@Tags({"Amazon", "DynamoDB", "AWS", "Get", "Fetch"}) +@CapabilityDescription("Retrieves a document from DynamoDB based on hash and range key. The key can be string or number." + + "For any get request all the parimary keys are required (hash or hash and range based on the table keys)") +@WritesAttributes({ + @WritesAttribute(attribute = AbstractDynamoDBProcessor.DYNAMODB_KEY_ERROR_UNPROCESSED, description = "Dynamo db unprocessed keys"), + @WritesAttribute(attribute = AbstractDynamoDBProcessor.DYNAMODB_RANGE_KEY_VALUE_ERROR, description = "Dynamod db range key error"), + @WritesAttribute(attribute = AbstractDynamoDBProcessor.DYNAMODB_KEY_ERROR_NOT_FOUND, description = "Dynamo db key not found"), + @WritesAttribute(attribute = AbstractDynamoDBProcessor.DYNAMODB_ERROR_EXCEPTION_MESSAGE, description = "Dynamo db exception message"), + @WritesAttribute(attribute = AbstractDynamoDBProcessor.DYNAMODB_ERROR_CODE, description = "Dynamo db error code"), + @WritesAttribute(attribute = AbstractDynamoDBProcessor.DYNAMODB_ERROR_MESSAGE, description = "Dynamo db error message"), + @WritesAttribute(attribute = AbstractDynamoDBProcessor.DYNAMODB_ERROR_TYPE, description = "Dynamo db error type"), + @WritesAttribute(attribute = AbstractDynamoDBProcessor.DYNAMODB_ERROR_SERVICE, description = "Dynamo db error service"), + @WritesAttribute(attribute = AbstractDynamoDBProcessor.DYNAMODB_ERROR_RETRYABLE, description = "Dynamo db error is retryable"), + @WritesAttribute(attribute = AbstractDynamoDBProcessor.DYNAMODB_ERROR_REQUEST_ID, description = "Dynamo db error request id"), + @WritesAttribute(attribute = AbstractDynamoDBProcessor.DYNAMODB_ERROR_STATUS_CODE, description = "Dynamo db status code") + }) +@ReadsAttributes({ + @ReadsAttribute(attribute = AbstractDynamoDBProcessor.DYNAMODB_ITEM_HASH_KEY_VALUE, description = "Items hash key value" ), + @ReadsAttribute(attribute = AbstractDynamoDBProcessor.DYNAMODB_ITEM_RANGE_KEY_VALUE, description = "Items range key value" ), + }) +public class GetDynamoDB extends AbstractDynamoDBProcessor { + + public static final List<PropertyDescriptor> properties = Collections.unmodifiableList( + Arrays.asList(TABLE, HASH_KEY_NAME, RANGE_KEY_NAME, HASH_KEY_VALUE, RANGE_KEY_VALUE, + HASH_KEY_VALUE_TYPE, RANGE_KEY_VALUE_TYPE, JSON_DOCUMENT, BATCH_SIZE, REGION, ACCESS_KEY, SECRET_KEY, + CREDENTIALS_FILE, AWS_CREDENTIALS_PROVIDER_SERVICE, TIMEOUT, SSL_CONTEXT_SERVICE)); + + @Override + protected List<PropertyDescriptor> getSupportedPropertyDescriptors() { + return properties; + } + + @Override + public void onTrigger(final ProcessContext context, final ProcessSession session) { + List<FlowFile> flowFiles = session.get(context.getProperty(BATCH_SIZE).asInteger()); + if (flowFiles == null || flowFiles.size() == 0) { + return; + } + + Map<ItemKeys,FlowFile> keysToFlowFileMap = new HashMap<>(); + + final String table = context.getProperty(TABLE).getValue(); + TableKeysAndAttributes tableKeysAndAttributes = new TableKeysAndAttributes(table); + + final String hashKeyName = context.getProperty(HASH_KEY_NAME).getValue(); + final String rangeKeyName = context.getProperty(RANGE_KEY_NAME).getValue(); + final String jsonDocument = context.getProperty(JSON_DOCUMENT).getValue(); + + for (FlowFile flowFile : flowFiles) { + final Object hashKeyValue = getValue(context, HASH_KEY_VALUE_TYPE, HASH_KEY_VALUE, flowFile); + final Object rangeKeyValue = getValue(context, RANGE_KEY_VALUE_TYPE, RANGE_KEY_VALUE, flowFile); + + if ( ! isHashKeyValueConsistent(hashKeyName, hashKeyValue, session, flowFile)) { + continue; + } + + if ( ! isRangeKeyValueConsistent(rangeKeyName, rangeKeyValue, session, flowFile) ) { + continue; + } + + keysToFlowFileMap.put(new ItemKeys(hashKeyValue, rangeKeyValue), flowFile); + + if ( rangeKeyValue == null || StringUtils.isBlank(rangeKeyValue.toString()) ) { + tableKeysAndAttributes.addHashOnlyPrimaryKey(hashKeyName, hashKeyValue); + } else { + tableKeysAndAttributes.addHashAndRangePrimaryKey(hashKeyName, hashKeyValue, rangeKeyName, rangeKeyValue); + } + } + + if (keysToFlowFileMap.isEmpty()) { + return; + } + + final DynamoDB dynamoDB = getDynamoDB(); + + try { + BatchGetItemOutcome result = dynamoDB.batchGetItem(tableKeysAndAttributes); + + // Handle processed items and get the json document + List<Item> items = result.getTableItems().get(table); + for (Item item : items) { + ItemKeys itemKeys = new ItemKeys(item.get(hashKeyName), item.get(rangeKeyName)); + FlowFile flowFile = keysToFlowFileMap.get(itemKeys); + + ByteArrayInputStream bais = new ByteArrayInputStream(item.getJSON(jsonDocument).getBytes()); + flowFile = session.importFrom(bais, flowFile); + + session.transfer(flowFile,REL_SUCCESS); + keysToFlowFileMap.remove(itemKeys); + } + + // Handle unprocessed keys + Map<String, KeysAndAttributes> unprocessedKeys = result.getUnprocessedKeys(); + if ( unprocessedKeys != null && unprocessedKeys.size() > 0) { + KeysAndAttributes keysAndAttributes = unprocessedKeys.get(table); + List<Map<String, AttributeValue>> keys = keysAndAttributes.getKeys(); + + for (Map<String,AttributeValue> unprocessedKey : keys) { + Object hashKeyValue = unprocessedKey.get(hashKeyName); + Object rangeKeyValue = unprocessedKey.get(rangeKeyName); + sendUnhandledToFailure(session, keysToFlowFileMap, hashKeyValue, rangeKeyValue); + } + } + + // Handle any remaining items + for (ItemKeys key : keysToFlowFileMap.keySet()) { + FlowFile flowFile = keysToFlowFileMap.get(key); + flowFile = session.putAttribute(flowFile, DYNAMODB_KEY_ERROR_NOT_FOUND, DYNAMODB_KEY_ERROR_NOT_FOUND_MESSAGE + key.toString() ); + session.transfer(flowFile,REL_FAILURE); + keysToFlowFileMap.remove(key); + } + + } catch(AmazonServiceException exception) { + getLogger().error("Could not process flowFiles due to exception : " + exception.getMessage()); + List<FlowFile> failedFlowFiles = processException(session, flowFiles, exception); + session.transfer(failedFlowFiles, REL_FAILURE); + } catch(AmazonClientException exception) { + getLogger().error("Could not process flowFiles due to exception : " + exception.getMessage()); + List<FlowFile> failedFlowFiles = processException(session, flowFiles, exception); + session.transfer(failedFlowFiles, REL_FAILURE); + } catch(Exception exception) { + getLogger().error("Could not process flowFiles due to exception : " + exception.getMessage()); + List<FlowFile> failedFlowFiles = processException(session, flowFiles, exception); + session.transfer(failedFlowFiles, REL_FAILURE); --- End diff -- Made helper methods explicit.
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