Github user olegz commented on a diff in the pull request:
https://github.com/apache/nifi/pull/224#discussion_r54296973
--- 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 --
similar comment as above about exception handling
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