Java KeySchemaElement.getAttributeName方法代碼示例

import com.amazonaws.services.dynamodbv2.model.KeySchemaElement; //導入方法依賴的package包/類
/**
 * Builds hash key attribute from generic query received.
 * 
 * @param qKey
 * 
 * @returnAttributeValue build from query
 */
private Map<String, AttributeValue> buildHashKey(K qKey) {
  Map<String, AttributeValue> hashKey = new HashMap<>();
  for (KeySchemaElement key : getKeySchema()) {
    AttributeValue attr = new AttributeValue();
    if (key.getKeyType().equals(KeyType.HASH.toString())) {
      if (keyItems.get(key.getAttributeName()).equals("N")) {
        attr.withN(getHashKey(qKey).toString());
      } else if (keyItems.get(key.getAttributeName()).equals("S")) {
        attr.withS(getHashKey(qKey).toString());
      } else if (keyItems.get(key.getAttributeName()).equals("B")) {
        attr.withB(ByteBuffer.wrap(getHashKey(qKey).toString().getBytes(Charset.defaultCharset())));
      } else {
        throw new IllegalArgumentException("Data type not supported for "
            + key.getAttributeName());
      }
      hashKey.put(key.getAttributeName(), attr);
    }
  }
  if (hashKey.isEmpty()) {
    throw new IllegalStateException("No key value has been defined.");
  }
  return hashKey;
}
 

import com.amazonaws.services.dynamodbv2.model.KeySchemaElement; //導入方法依賴的package包/類
/**
 * Builds range key attribute from generic query received.
 * 
 * @param qKey
 * 
 * @return
 */
private Map<String, AttributeValue> buildRangeKey(K qKey) {
  Map<String, AttributeValue> kAttrs = new HashMap<>();
  for (KeySchemaElement key : getKeySchema()) {
    AttributeValue attr = new AttributeValue();
    if (key.getKeyType().equals(KeyType.RANGE.toString())) {
      if (keyItems.get(key.getAttributeName()).equals("N")) {
        attr.withN(getRangeKey(qKey).toString());
      } else if (keyItems.get(key.getAttributeName()).equals("S")) {
        attr.withS(getRangeKey(qKey).toString());
      } else if (keyItems.get(key.getAttributeName()).equals("B")) {
        attr.withB(ByteBuffer.wrap(getRangeKey(qKey).toString().getBytes(Charset.defaultCharset())));
      } else {
        throw new IllegalArgumentException("Data type not supported for "
            + key.getAttributeName());
      }
      kAttrs.put(key.getAttributeName(), attr);
    }
  }
  return kAttrs;
}
 

import com.amazonaws.services.dynamodbv2.model.KeySchemaElement; //導入方法依賴的package包/類
private void addColumnFromKeySchema(String indexName, List<KeySchemaElement> keySchema, MutableTable table,
        boolean primaryKey) {
    for (final KeySchemaElement keySchemaElement : keySchema) {
        final String attributeName = keySchemaElement.getAttributeName();
        if (table.getColumnByName(attributeName) == null) {
            final String keyType = keySchemaElement.getKeyType();
            final MutableColumn column = new MutableColumn(attributeName, table).setPrimaryKey(primaryKey);
            appendRemarks(column, indexName + " member ('" + keyType + "' type)");
            table.addColumn(column);
        }
    }
}
 

import com.amazonaws.services.dynamodbv2.model.KeySchemaElement; //導入方法依賴的package包/類
public static void cleanupAggTable(AWSCredentialsProvider credentials,
		Region region, final String dynamoTable, final String toSeq)
		throws Exception {
	final Double deleteBelow = Double.parseDouble(toSeq);

	// create two clients - one synchronous for the read of all candidate
	// values, and another for the delete operations
	final AmazonDynamoDB dynamoClient = new AmazonDynamoDBClient(
			credentials);
	if (region != null)
		dynamoClient.setRegion(region);
	final AmazonDynamoDBAsyncClient deleteCli = new AmazonDynamoDBAsyncClient(
			credentials);
	deleteCli.setRegion(region);
	Map<String, AttributeValue> lastKey = null;
	Map<String, AttributeValue> deleteKey = null;

	// work out what the key and date column name is
	String keyColumn = null;
	String dateColumn = null;

	List<KeySchemaElement> keySchema = dynamoClient
			.describeTable(dynamoTable).getTable().getKeySchema();
	for (KeySchemaElement element : keySchema) {
		if (element.getKeyType().equals(KeyType.HASH.name()))
			keyColumn = element.getAttributeName();

		if (element.getKeyType().equals(KeyType.RANGE.name()))
			dateColumn = element.getAttributeName();
	}

	LOG.info(String.format(
			"Deleting data from %s where %s values are below %s",
			dynamoTable, StreamAggregator.LAST_WRITE_SEQ, deleteBelow));
	int deleteCount = 0;

	do {
		// read data from the table
		ScanRequest scan = new ScanRequest()
				.withTableName(dynamoTable)
				.withAttributesToGet(keyColumn, dateColumn,
						StreamAggregator.LAST_WRITE_SEQ)
				.withExclusiveStartKey(lastKey);

		ScanResult results = dynamoClient.scan(scan);

		// delete everything up to the system provided change number
		for (Map<String, AttributeValue> map : results.getItems()) {
			deleteKey = new HashMap<>();
			deleteKey.put(keyColumn, map.get(keyColumn));
			deleteKey.put(dateColumn, map.get(dateColumn));

			if (Double.parseDouble(map.get(StreamAggregator.LAST_WRITE_SEQ)
					.getS()) < deleteBelow) {
				deleteCli.deleteItem(dynamoTable, deleteKey);
				deleteCount++;
			}
		}
		lastKey = results.getLastEvaluatedKey();
	} while (lastKey != null);

	LOG.info(String.format(
			"Operation Complete - %s Records removed from Aggregate Store",
			deleteCount));
}