@Override
	protected void doWrite(Message<?> message) throws Exception {
		Assert.notNull(storePartitionWriter, "Writer already closed");
		Object payload = message.getPayload();
		if (payload instanceof String) {
			storePartitionWriter.write((String) payload, message);
		}
		else {
			throw new MessageHandlingException(message,
					"message not a String");
		}
	}
Instantiates a new hdfs partition data store message handler.

@param storePartitionWriter the store partition writer
spring-xd-hadoop/src/main/java/org/springframework/xd/integration/hadoop/outbound/HdfsPartitionDataStoreMessageHandler.java