com.helger.commons.csv

Class CSVReader

java.lang.Object

com.helger.commons.csv.CSVReader

All Implemented Interfaces:

ICommonsIterable<ICommonsList<String>>, Closeable, AutoCloseable, Iterable<ICommonsList<String>>

public class CSVReader
extends Object
implements Closeable, ICommonsIterable<ICommonsList<String>>

A very simple CSV reader released under a commercial-friendly license.

Author:

Glen Smith, Philip Helger

Constructor Summary

Constructors

Constructor and Description
CSVReader(Reader aReader) Constructs CSVReader using a comma for the separator.
CSVReader(Reader aReader, boolean bKeepCR) Constructs CSVReader using a comma for the separator.
CSVReader(Reader aReader, CSVParser aParser, boolean bKeepCR) Constructs CSVReader with supplied CSVParser.

Method Summary

Modifier and Type	Method and Description
void	close() Closes the underlying reader.
char	getEscapeChar()
CSVParser	getParser()
char	getQuoteChar()
char	getSeparatorChar()
int	getSkipLines() Returns the number of lines in the csv file to skip before processing.
boolean	isIgnoreLeadingWhiteSpace()
boolean	isIgnoreQuotations()
boolean	isKeepCarriageReturns() Returns if the reader will keep carriage returns found in data or remove them.
boolean	isStrictQuotes()
boolean	isVerifyReader() Returns if the CSVReader will verify the reader before each read.
Iterator<ICommonsList<String>>	iterator() Creates an Iterator for processing the csv data.
ICommonsList<ICommonsList<String>>	readAll() Reads the entire file into a list with each element being a list of String of tokens.
void	readAll(Consumer<? super ICommonsList<String>> aLineConsumer) Reads the entire file line by line and invoke a callback for each line.
ICommonsList<String>	readNext() Reads the next line from the buffer and converts to a string array.
CSVReader	setEscapeChar(char cEscapeChar) Sets the character to use for escaping a separator or quote.
CSVReader	setIgnoreLeadingWhiteSpace(boolean bIgnoreLeadingWhiteSpace) Sets the ignore leading whitespace setting - if true, white space in front of a quote in a field is ignored.
CSVReader	setIgnoreQuotations(boolean bIgnoreQuotations) Sets the ignore quotations mode - if true, quotations are ignored.
CSVReader	setQuoteChar(char cQuoteChar) Sets the character to use for quoted elements.
CSVReader	setSeparatorChar(char cSeparator) Sets the delimiter to use for separating entries.
CSVReader	setSkipLines(int nSkipLines) Sets the line number to skip for start reading.
CSVReader	setStrictQuotes(boolean bStrictQuotes) Sets the strict quotes setting - if true, characters outside the quotes are ignored.
CSVReader	setVerifyReader(boolean bVerifyReader) Checks to see if the CSVReader should verify the reader state before reads or not.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.helger.commons.collection.impl.ICommonsIterable

containsAny, containsNone, containsOnly, findAll, findAllInstanceOf, findAllMapped, findAllMapped, findAllMapped, findFirst, findFirst, findFirstIndex, findFirstMapped, findFirstMapped, findLastIndex, forEach, forEachBreakable, forEachByIndex, getCount, getCount

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

CSVReader

public CSVReader(@Nonnull @WillCloseWhenClosed
                 Reader aReader)

Constructs CSVReader using a comma for the separator.

Parameters:

aReader - the reader to an underlying CSV source.

CSVReader

public CSVReader(@Nonnull @WillCloseWhenClosed
                 Reader aReader,
                 boolean bKeepCR)

Constructs CSVReader using a comma for the separator.

Parameters:

aReader - the reader to an underlying CSV source.

bKeepCR - true to keep carriage returns in data read, false otherwise

CSVReader

public CSVReader(@Nonnull @WillCloseWhenClosed
                 Reader aReader,
                 @Nonnull
                 CSVParser aParser,
                 boolean bKeepCR)

Constructs CSVReader with supplied CSVParser.

Parameters:

aReader - the reader to an underlying CSV source.

aParser - the parser to use to parse input

bKeepCR - true to keep carriage returns in data read, false otherwise

Method Detail

getParser

@Nonnull
public CSVParser getParser()

Returns:

the CSVParser used by the reader.

getSeparatorChar

public char getSeparatorChar()

Returns:

The default separator for this parser.

setSeparatorChar

@Nonnull
public CSVReader setSeparatorChar(char cSeparator)

Sets the delimiter to use for separating entries.

Parameters:

cSeparator - the delimiter to use for separating entries

Returns:

this

getQuoteChar

public char getQuoteChar()

Returns:

The default quotation character for this parser.

setQuoteChar

@Nonnull
public CSVReader setQuoteChar(char cQuoteChar)

Sets the character to use for quoted elements.

Parameters:

cQuoteChar - the character to use for quoted element.

Returns:

this

getEscapeChar

public char getEscapeChar()

Returns:

The default escape character for this parser.

setEscapeChar

@Nonnull
public CSVReader setEscapeChar(char cEscapeChar)

Sets the character to use for escaping a separator or quote.

Parameters:

cEscapeChar - the character to use for escaping a separator or quote.

Returns:

this

isStrictQuotes

public boolean isStrictQuotes()

Returns:

The default strictQuotes setting for this parser.

setStrictQuotes

@Nonnull
public CSVReader setStrictQuotes(boolean bStrictQuotes)

Sets the strict quotes setting - if true, characters outside the quotes are ignored.

Parameters:

bStrictQuotes - if true, characters outside the quotes are ignored

Returns:

this

isIgnoreLeadingWhiteSpace

public boolean isIgnoreLeadingWhiteSpace()

Returns:

The default ignoreLeadingWhiteSpace setting for this parser.

setIgnoreLeadingWhiteSpace

@Nonnull
public CSVReader setIgnoreLeadingWhiteSpace(boolean bIgnoreLeadingWhiteSpace)

Sets the ignore leading whitespace setting - if true, white space in front of a quote in a field is ignored.

Parameters:

bIgnoreLeadingWhiteSpace - if true, white space in front of a quote in a field is ignored

Returns:

this

isIgnoreQuotations

public boolean isIgnoreQuotations()

Returns:

the default ignoreQuotation setting for this parser.

setIgnoreQuotations

@Nonnull
public CSVReader setIgnoreQuotations(boolean bIgnoreQuotations)

Sets the ignore quotations mode - if true, quotations are ignored.

Parameters:

bIgnoreQuotations - if true, quotations are ignored

Returns:

this

getSkipLines

@Nonnegative
public int getSkipLines()

Returns the number of lines in the csv file to skip before processing. This is useful when there is miscellaneous data at the beginning of a file.

Returns:

the number of lines in the csv file to skip before processing.

setSkipLines

@Nonnull
public CSVReader setSkipLines(@Nonnegative
                                        int nSkipLines)

Sets the line number to skip for start reading.

Parameters:

nSkipLines - the line number to skip for start reading.

Returns:

this

isKeepCarriageReturns

public boolean isKeepCarriageReturns()

Returns if the reader will keep carriage returns found in data or remove them.

Returns:

true if reader will keep carriage returns, false otherwise.

isVerifyReader

public boolean isVerifyReader()

Returns if the CSVReader will verify the reader before each read.
By default the value is true which is the functionality for version 3.0. If set to false the reader is always assumed ready to read - this is the functionality for version 2.4 and before.
The reason this method was needed was that certain types of Readers would return false for its ready() method until a read was done (namely readers created using Channels). This caused opencsv not to read from those readers.
Source: https://sourceforge.net/p/opencsv/bugs/108/

Returns:

true if CSVReader will verify the reader before reads. false otherwise.

setVerifyReader

@Nonnull
public CSVReader setVerifyReader(boolean bVerifyReader)

Checks to see if the CSVReader should verify the reader state before reads or not. This should be set to false if you are using some form of asynchronous reader (like readers created by the java.nio.* classes). The default value is true.

Parameters:

bVerifyReader - true if CSVReader should verify reader before each read, false otherwise.

Returns:

this

readAll

@Nonnull
 @ReturnsMutableCopy
public ICommonsList<ICommonsList<String>> readAll()
                                                                           throws IOException

Reads the entire file into a list with each element being a list of String of tokens.

Returns:

a list of list of String, with each inner list of String representing a line of the file.

Throws:

IOException - if bad things happen during the read

readAll

public void readAll(@Nonnull
                    Consumer<? super ICommonsList<String>> aLineConsumer)
             throws IOException

Reads the entire file line by line and invoke a callback for each line.

Parameters:

aLineConsumer - The consumer that is invoked for every line. May not be null.

Throws:

IOException - if bad things happen during the read

readNext

@Nullable
public ICommonsList<String> readNext()
                                         throws IOException

Reads the next line from the buffer and converts to a string array.

Returns:

a string array with each comma-separated element as a separate entry.

Throws:

IOException - if bad things happen during the read

close

public void close()
           throws IOException

Closes the underlying reader.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException - if the close fails

iterator

@Nonnull
public Iterator<ICommonsList<String>> iterator()

Creates an Iterator for processing the csv data.

Specified by:

iterator in interface Iterable<ICommonsList<String>>

Returns:

an ICommonsList<String> iterator.