ExtractorLineAggregator (Spring Batch 4.1.4.RELEASE API)

java.lang.Object
- org.springframework.batch.item.file.transform.ExtractorLineAggregator<T>

All Implemented Interfaces:
LineAggregator<T>
Direct Known Subclasses:
DelimitedLineAggregator, FormatterLineAggregator
```
public abstract class ExtractorLineAggregator<T>
extends java.lang.Object
implements LineAggregator<T>
```
An abstract LineAggregator implementation that utilizes a FieldExtractor to convert the incoming object to an array of its parts. Extending classes must decide how those parts will be aggregated together.
Since:
2.0
Author:
Dan Garrette

Constructor Summary
Constructors
Constructor Description
ExtractorLineAggregator()

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`java.lang.String`	`aggregate(T item)`	Extract fields from the given item using the `FieldExtractor` and then aggregate them.
`protected abstract java.lang.String`	`doAggregate(java.lang.Object[] fields)`	Aggregate provided fields into single String.
`void`	`setFieldExtractor(FieldExtractor<T> fieldExtractor)`	Public setter for the field extractor responsible for splitting an input object up into an array of objects.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - ExtractorLineAggregator
```
public ExtractorLineAggregator()
```
- Method Detail
  - setFieldExtractor
```
public void setFieldExtractor(FieldExtractor<T> fieldExtractor)
```
    Public setter for the field extractor responsible for splitting an input object up into an array of objects. Defaults to PassThroughFieldExtractor.
    Parameters:
    fieldExtractor - The field extractor to set
  - aggregate
```
public java.lang.String aggregate(T item)
```
    Extract fields from the given item using the FieldExtractor and then aggregate them. Any null field returned by the extractor will be replaced by an empty String. Null items are not allowed.
    Specified by:
    aggregate in interface LineAggregator<T>
    Parameters:
    item - values to be converted
    Returns:
    string
    See Also:
    LineAggregator.aggregate(java.lang.Object)
  - doAggregate
```
protected abstract java.lang.String doAggregate(java.lang.Object[] fields)
```
    Aggregate provided fields into single String.
    Parameters:
    fields - An array of the fields that must be aggregated
    Returns:
    aggregated string