Example usage for com.amazonaws.services.dynamodbv2.document TableKeysAndAttributes addHashAndRangePrimaryKey

Introduction

In this page you can find the example usage for com.amazonaws.services.dynamodbv2.document TableKeysAndAttributes addHashAndRangePrimaryKey.

Prototype

public TableKeysAndAttributes addHashAndRangePrimaryKey(String hashKeyName, Object hashKeyValue,
        String rangeKeyName, Object rangeKeyValue) 

Source Link

Document

Adds a primary key (that consists of a hash-key and a range-key) to be included in the batch get-item operation.

Usage

From source file:org.apache.nifi.processors.aws.dynamodb.GetDynamoDB.java

License:Apache License

@Override
public void onTrigger(final ProcessContext context, final ProcessSession session) {
    List<FlowFile> flowFiles = session
            .get(context.getProperty(BATCH_SIZE).evaluateAttributeExpressions().asInteger());
    if (flowFiles == null || flowFiles.size() == 0) {
        return;/*from  w ww.  java 2s .c  om*/
    }

    Map<ItemKeys, FlowFile> keysToFlowFileMap = new HashMap<>();

    final String table = context.getProperty(TABLE).evaluateAttributeExpressions().getValue();
    TableKeysAndAttributes tableKeysAndAttributes = new TableKeysAndAttributes(table);

    final String hashKeyName = context.getProperty(HASH_KEY_NAME).evaluateAttributeExpressions().getValue();
    final String rangeKeyName = context.getProperty(RANGE_KEY_NAME).evaluateAttributeExpressions().getValue();
    final String jsonDocument = context.getProperty(JSON_DOCUMENT).evaluateAttributeExpressions().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);

            if (item.get(jsonDocument) != null) {
                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 = getAttributeValue(context, HASH_KEY_VALUE_TYPE,
                        unprocessedKey.get(hashKeyName));
                Object rangeKeyValue = getAttributeValue(context, RANGE_KEY_VALUE_TYPE,
                        unprocessedKey.get(rangeKeyName));
                sendUnprocessedToUnprocessedRelationship(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_NOT_FOUND);
            keysToFlowFileMap.remove(key);
        }

    } catch (AmazonServiceException exception) {
        getLogger().error("Could not process flowFiles due to service exception : " + exception.getMessage());
        List<FlowFile> failedFlowFiles = processServiceException(session, flowFiles, exception);
        session.transfer(failedFlowFiles, REL_FAILURE);
    } catch (AmazonClientException exception) {
        getLogger().error("Could not process flowFiles due to client exception : " + exception.getMessage());
        List<FlowFile> failedFlowFiles = processClientException(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);
    }
}

---