Package com.broadleafcommerce.datafeed.service.publisher.file.support

Class StreamingJsonArrayFileReader<T>

java.lang.Object

com.broadleafcommerce.datafeed.service.publisher.file.support.StreamingJsonArrayFileReader<T>

Type Parameters:

T - the POJO type to deserialize each array element into

public class StreamingJsonArrayFileReader<T>
extends Object

Useful for reading through a file which is just a JSON array of objects (ex: typically what is in DataFeedProcessExecution.getQueriedDataFileLocation() when using AbstractJsonArrayDataFeedCollector). This utility allows consumers to read elements from such a file in a streaming fashion (to avoid loading everything into memory at once).

This is not intended to be a bean, and is expected to be manually instantiated and used to process a specific file.

Constructor Summary

Constructors

Constructor	Description
StreamingJsonArrayFileReader(com.fasterxml.jackson.databind.ObjectMapper objectMapper, Class<T> deserializedElementType, int maxElementsToReadInBatch, Consumer<List<T>> elementBatchHandler, Path fileToProcess)	Creates a new StreamingJsonArrayFileReader instance.

Method Summary

Modifier and Type	Method	Description
protected Class<T>	getDeserializedElementType()	The POJO type to deserialize each element into.
protected Consumer<List<T>>	getElementBatchHandler()	A callback that will do work on a batch of read elements.
protected Path	getFileToProcess()	The JSON array file to process.
protected int	getMaxElementsToReadInBatch()	The number of elements to load into memory and transform at a time.
protected com.fasterxml.jackson.databind.ObjectMapper	getObjectMapper()	The ObjectMapper to use for deserialization.
void	read()	Reference for streaming processing

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

StreamingJsonArrayFileReader

public StreamingJsonArrayFileReader(com.fasterxml.jackson.databind.ObjectMapper objectMapper,
 Class<T> deserializedElementType,
 int maxElementsToReadInBatch,
 Consumer<List<T>> elementBatchHandler,
 Path fileToProcess)

Creates a new StreamingJsonArrayFileReader instance.

Parameters:

objectMapper - The ObjectMapper to use for deserialization.

deserializedElementType - The POJO type to deserialize each element into.

maxElementsToReadInBatch - The number of elements to load into memory and transform at a time.

elementBatchHandler - A callback that will do work on a batch of read elements.

fileToProcess - The JSON array file to process.

Method Details

read

public void read()
          throws IOException

Reference for streaming processing

Throws:

IOException - if something went wrong

getObjectMapper

protected com.fasterxml.jackson.databind.ObjectMapper getObjectMapper()

The ObjectMapper to use for deserialization.

getDeserializedElementType

protected Class<T> getDeserializedElementType()

The POJO type to deserialize each element into.

getMaxElementsToReadInBatch

protected int getMaxElementsToReadInBatch()

The number of elements to load into memory and transform at a time.

getElementBatchHandler

protected Consumer<List<T>> getElementBatchHandler()

A callback that will do work on a batch of read elements.

getFileToProcess

protected Path getFileToProcess()

The JSON array file to process.