Class IndexedCsvReader<T>

java.lang.Object

de.siegmar.fastcsv.reader.IndexedCsvReader<T>

Type Parameters:

T - the type of the CSV record.

All Implemented Interfaces:

Closeable, AutoCloseable

public final class IndexedCsvReader<T>
extends Object
implements Closeable

CSV reader implementation for indexed based access.

If no prebuilt index passed in (via IndexedCsvReader.IndexedCsvReaderBuilder.index(CsvIndex)) the constructor will initiate indexing the file. This process is optimized on performance and low memory usage – no CSV data is stored in memory. The current status can be monitored via IndexedCsvReader.IndexedCsvReaderBuilder.statusListener(StatusListener).

This class is thread-safe.

Example use:

 try (IndexedCsvReader<CsvRecord> csv = IndexedCsvReader.builder().ofCsvRecord(file)) {
     CsvIndex index = csv.getIndex();
     int lastPage = index.getPageCount() - 1;
     List<CsvRecord> csvRecords = csv.readPage(lastPage);
 }

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	IndexedCsvReader.IndexedCsvReaderBuilder	This builder is used to create configured instances of IndexedCsvReader.
private final class	IndexedCsvReader.ScannerListener

Field Summary

Fields

Modifier and Type	Field	Description
private final boolean	acceptCharsAfterQuotes
private final Charset	charset
private final char	commentCharacter
private final CommentStrategy	commentStrategy
private final CsvIndex	csvIndex
private final CsvParser	csvParser
private final CsvCallbackHandler<T>	csvRecordHandler
private final char	fieldSeparator
private final Path	file
private final int	pageSize
private final char	quoteCharacter
private final RandomAccessFile	raf

Constructor Summary

Constructors

Constructor	Description
IndexedCsvReader(Path file, Charset defaultCharset, char fieldSeparator, char quoteCharacter, CommentStrategy commentStrategy, char commentCharacter, boolean acceptCharsAfterQuotes, int pageSize, CsvCallbackHandler<T> csvRecordHandler, CsvIndex csvIndex, StatusListener statusListener)

Method Summary

Modifier and Type	Method	Description
static IndexedCsvReader.IndexedCsvReaderBuilder	builder()	Constructs a IndexedCsvReader.IndexedCsvReaderBuilder to configure and build instances of this class.
private CsvIndex	buildIndex(int bomHeaderLength, StatusListener statusListener)
void	close()
private static Optional<BomHeader>	detectBom(Path file, StatusListener statusListener)
CsvIndex	getIndex()	Get the index used for accessing the CSV file.
List<T>	readPage(int page)	Reads a page of records.
private List<T>	readPage(CsvIndex.CsvPage page)
String	toString()
private static CsvIndex	validatePrebuiltIndex(Path file, int bomHeaderLength, byte fieldSeparator, byte quoteCharacter, CommentStrategy commentStrategy, byte commentCharacter, CsvIndex csvIndex)

Methods inherited from class Object

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

Field Details

file

private final Path file

charset

private final Charset charset

fieldSeparator

private final char fieldSeparator

quoteCharacter

private final char quoteCharacter

commentStrategy

private final CommentStrategy commentStrategy

commentCharacter

private final char commentCharacter

acceptCharsAfterQuotes

private final boolean acceptCharsAfterQuotes

pageSize

private final int pageSize

raf

private final RandomAccessFile raf

csvRecordHandler

private final CsvCallbackHandler<T> csvRecordHandler

csvParser

private final CsvParser csvParser

csvIndex

private final CsvIndex csvIndex

Constructor Details

IndexedCsvReader

IndexedCsvReader(Path file,
 Charset defaultCharset,
 char fieldSeparator,
 char quoteCharacter,
 CommentStrategy commentStrategy,
 char commentCharacter,
 boolean acceptCharsAfterQuotes,
 int pageSize,
 CsvCallbackHandler<T> csvRecordHandler,
 CsvIndex csvIndex,
 StatusListener statusListener)
          throws IOException

Throws:

IOException

Method Details

detectBom

private static Optional<BomHeader> detectBom(Path file,
 StatusListener statusListener)
                                      throws IOException

Throws:

IOException

validatePrebuiltIndex

private static CsvIndex validatePrebuiltIndex(Path file,
 int bomHeaderLength,
 byte fieldSeparator,
 byte quoteCharacter,
 CommentStrategy commentStrategy,
 byte commentCharacter,
 CsvIndex csvIndex)
                                       throws IOException

Throws:

IOException

buildIndex

private CsvIndex buildIndex(int bomHeaderLength,
 StatusListener statusListener)
                     throws IOException

Throws:

IOException

builder

public static IndexedCsvReader.IndexedCsvReaderBuilder builder()

Constructs a IndexedCsvReader.IndexedCsvReaderBuilder to configure and build instances of this class.

Returns:

a new IndexedCsvReader.IndexedCsvReaderBuilder instance.

getIndex

public CsvIndex getIndex()

Get the index used for accessing the CSV file. That index is either a freshly built index or the index that has been passed via IndexedCsvReader.IndexedCsvReaderBuilder.index(CsvIndex).

Returns:

the index that is used for accessing the CSV file.

readPage

public List<T> readPage(int page)
                 throws IOException

Reads a page of records.

Parameters:

page - the page to read (0-based).

Returns:

a page of records, never null.

Throws:

IOException - if an I/O error occurs.

IllegalArgumentException - if page is < 0

IndexOutOfBoundsException - if the file does not contain the specified page

readPage

private List<T> readPage(CsvIndex.CsvPage page)
                  throws IOException

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

IOException

toString

public String toString()

Overrides:

toString in class Object