Package org.springframework.batch.item.file

Class FlatFileItemReader<T>

java.lang.Object

org.springframework.batch.item.ItemStreamSupport

org.springframework.batch.item.support.AbstractItemStreamItemReader<T>

org.springframework.batch.item.support.AbstractItemCountingItemStreamItemReader<T>

org.springframework.batch.item.file.FlatFileItemReader<T>

All Implemented Interfaces:

ResourceAwareItemReaderItemStream<T>, ItemReader<T>, ItemStream, ItemStreamReader<T>

public class FlatFileItemReader<T>
extends AbstractItemCountingItemStreamItemReader<T>
implements ResourceAwareItemReaderItemStream<T>

Restartable ItemReader that reads lines from input setResource(Resource). Line is defined by the setRecordSeparatorPolicy(RecordSeparatorPolicy) and mapped to item using setLineMapper(LineMapper). If an exception is thrown during line mapping it is rethrown as FlatFileParseException adding information about the problematic line and its line number.

This reader is not thread-safe.

Author:

Robert Kasanicky, Mahmoud Ben Hassine, Stefano Cordio

Field Summary

Fields

Modifier and Type	Field	Description
protected String[]	comments
static final String	DEFAULT_CHARSET
static final String[]	DEFAULT_COMMENT_PREFIXES

Constructor Summary

Constructors

Constructor	Description
FlatFileItemReader(LineMapper<T> lineMapper)	Create a new FlatFileItemReader with a LineMapper.
FlatFileItemReader(org.springframework.core.io.Resource resource, LineMapper<T> lineMapper)	Create a new FlatFileItemReader with a Resource and a LineMapper.

Method Summary

Modifier and Type	Method	Description
protected void	doClose()	Close the resources opened in AbstractItemCountingItemStreamItemReader.doOpen().
protected void	doOpen()	Open resources necessary to start reading input.
protected @Nullable T	doRead()	Read next item from input.
protected boolean	isComment(String line)
protected void	jumpToItem(int itemIndex)	Move to the given item index.
void	setBufferedReaderFactory(BufferedReaderFactory bufferedReaderFactory)	Factory for the BufferedReader that will be used to extract lines from the file.
void	setComments(String[] comments)	Setter for comment prefixes.
void	setEncoding(String encoding)	Setter for the encoding for this input source.
void	setLineMapper(LineMapper<T> lineMapper)	Setter for line mapper.
void	setLinesToSkip(int linesToSkip)	Public setter for the number of lines to skip at the start of a file.
void	setRecordSeparatorPolicy(RecordSeparatorPolicy recordSeparatorPolicy)	Public setter for the recordSeparatorPolicy.
void	setResource(@Nullable org.springframework.core.io.Resource resource)	Public setter for the input resource.
void	setSkippedLinesCallback(LineCallbackHandler skippedLinesCallback)
void	setStrict(boolean strict)	In strict mode the reader will throw an exception on AbstractItemCountingItemStreamItemReader.open(org.springframework.batch.item.ExecutionContext) if the input resource does not exist.

Methods inherited from class org.springframework.batch.item.support.AbstractItemCountingItemStreamItemReader

close, getCurrentItemCount, isSaveState, open, read, setCurrentItemCount, setMaxItemCount, setSaveState, update

Methods inherited from class org.springframework.batch.item.ItemStreamSupport

getExecutionContextKey, getName, setExecutionContextName, setName

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.springframework.batch.item.ItemReader

read

Methods inherited from interface org.springframework.batch.item.ItemStream

close, open, update

Field Details

DEFAULT_CHARSET

public static final String DEFAULT_CHARSET

DEFAULT_COMMENT_PREFIXES

public static final String[] DEFAULT_COMMENT_PREFIXES

comments

protected String[] comments

Constructor Details

FlatFileItemReader

public FlatFileItemReader(LineMapper<T> lineMapper)

Create a new FlatFileItemReader with a LineMapper.

Parameters:

lineMapper - to use to map lines to items

Since:

6.0

FlatFileItemReader

public FlatFileItemReader(org.springframework.core.io.Resource resource,
 LineMapper<T> lineMapper)

Create a new FlatFileItemReader with a Resource and a LineMapper.

Parameters:

resource - the input resource

lineMapper - to use to map lines to items

Since:

6.0

Method Details

setStrict

public void setStrict(boolean strict)

In strict mode the reader will throw an exception on AbstractItemCountingItemStreamItemReader.open(org.springframework.batch.item.ExecutionContext) if the input resource does not exist.

Parameters:

strict - true by default

setSkippedLinesCallback

public void setSkippedLinesCallback(LineCallbackHandler skippedLinesCallback)

Parameters:

skippedLinesCallback - will be called for each one of the initial skipped lines before any items are read.

setLinesToSkip

public void setLinesToSkip(int linesToSkip)

Public setter for the number of lines to skip at the start of a file. Can be used if the file contains a header without useful (column name) information, and without a comment delimiter at the beginning of the lines.

Parameters:

linesToSkip - the number of lines to skip

setLineMapper

public void setLineMapper(LineMapper<T> lineMapper)

Setter for line mapper. This property is required to be set.

Parameters:

lineMapper - maps line to item

setEncoding

public void setEncoding(String encoding)

Setter for the encoding for this input source. Default value is DEFAULT_CHARSET.

Parameters:

encoding - a properties object which possibly contains the encoding for this input file;

setBufferedReaderFactory

public void setBufferedReaderFactory(BufferedReaderFactory bufferedReaderFactory)

Factory for the BufferedReader that will be used to extract lines from the file. The default is fine for plain text files, but this is a useful strategy for binary files where the standard BufferedReader from java.io is limiting.

Parameters:

bufferedReaderFactory - the bufferedReaderFactory to set

setComments

public void setComments(String[] comments)

Setter for comment prefixes. Can be used to ignore header lines as well by using e.g. the first couple of column names as a prefix. Defaults to DEFAULT_COMMENT_PREFIXES.

Parameters:

comments - an array of comment line prefixes.

setResource

public void setResource(@Nullable org.springframework.core.io.Resource resource)

Public setter for the input resource.

Specified by:

setResource in interface ResourceAwareItemReaderItemStream<T>

setRecordSeparatorPolicy

public void setRecordSeparatorPolicy(RecordSeparatorPolicy recordSeparatorPolicy)

Public setter for the recordSeparatorPolicy. Used to determine where the line endings are and do things like continue over a line ending if inside a quoted string. Defaults to SimpleRecordSeparatorPolicy.

Parameters:

recordSeparatorPolicy - the recordSeparatorPolicy to set

doRead

protected @Nullable T doRead()
                      throws Exception

Description copied from class: AbstractItemCountingItemStreamItemReader

Read next item from input.

Specified by:

doRead in class AbstractItemCountingItemStreamItemReader<T>

Returns:

string corresponding to logical record according to setRecordSeparatorPolicy(RecordSeparatorPolicy) (might span multiple lines in file).

Throws:

Exception - Allows subclasses to throw checked exceptions for interpretation by the framework

isComment

protected boolean isComment(String line)

doClose

protected void doClose()
                throws Exception

Description copied from class: AbstractItemCountingItemStreamItemReader

Close the resources opened in AbstractItemCountingItemStreamItemReader.doOpen().

Specified by:

doClose in class AbstractItemCountingItemStreamItemReader<T>

Throws:

Exception - Allows subclasses to throw checked exceptions for interpretation by the framework

doOpen

protected void doOpen()
               throws Exception

Description copied from class: AbstractItemCountingItemStreamItemReader

Open resources necessary to start reading input.

Specified by:

doOpen in class AbstractItemCountingItemStreamItemReader<T>

Throws:

Exception - Allows subclasses to throw checked exceptions for interpretation by the framework

jumpToItem

protected void jumpToItem(int itemIndex)
                   throws Exception

Description copied from class: AbstractItemCountingItemStreamItemReader

Move to the given item index. Subclasses should override this method if there is a more efficient way of moving to given index than re-reading the input using AbstractItemCountingItemStreamItemReader.doRead().

Overrides:

jumpToItem in class AbstractItemCountingItemStreamItemReader<T>

Parameters:

itemIndex - index of item (0 based) to jump to.

Throws:

Exception - Allows subclasses to throw checked exceptions for interpretation by the framework