com.opencsv

Class CSVReader

java.lang.Object

com.opencsv.CSVReader

All Implemented Interfaces:

Closeable, AutoCloseable, Iterable<String[]>

public class CSVReader
extends Object
implements Closeable, Iterable<String[]>

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

Author:

Glen Smith

Field Summary

Fields

Modifier and Type	Field and Description
protected BufferedReader	br
static boolean	DEFAULT_KEEP_CR
static int	DEFAULT_MULTILINE_LIMIT The default limit for the number of lines in a multiline record.
static int	DEFAULT_SKIP_LINES The default line to start reading.
static boolean	DEFAULT_VERIFY_READER
protected Locale	errorLocale
protected boolean	hasNext
protected boolean	keepCR
protected LineReader	lineReader
protected long	linesRead
protected boolean	linesSkiped
protected int	multilineLimit
protected ICSVParser	parser
static int	READ_AHEAD_LIMIT
protected long	recordsRead
protected int	skipLines
protected boolean	verifyReader

Constructor Summary

Constructors

Constructor and Description
CSVReader(Reader reader) Constructs CSVReader using defaults for all parameters.
CSVReader(Reader reader, char separator) Deprecated. Please use CSVReaderBuilder instead.
CSVReader(Reader reader, char separator, char quotechar) Deprecated. Please use CSVReaderBuilder instead.
CSVReader(Reader reader, char separator, char quotechar, boolean strictQuotes) Deprecated. Please use CSVReaderBuilder instead.
CSVReader(Reader reader, char separator, char quotechar, char escape) Deprecated. Please use CSVReaderBuilder instead.
CSVReader(Reader reader, char separator, char quotechar, char escape, int line) Deprecated. Please use CSVReaderBuilder instead.
CSVReader(Reader reader, char separator, char quotechar, char escape, int line, boolean strictQuotes) Deprecated. Please use CSVReaderBuilder instead.
CSVReader(Reader reader, char separator, char quotechar, char escape, int line, boolean strictQuotes, boolean ignoreLeadingWhiteSpace) Deprecated. Please use CSVReaderBuilder instead.
CSVReader(Reader reader, char separator, char quotechar, char escape, int line, boolean strictQuotes, boolean ignoreLeadingWhiteSpace, boolean keepCR) Deprecated. Please use CSVReaderBuilder instead.
CSVReader(Reader reader, char separator, char quotechar, int line) Deprecated. Please use CSVReaderBuilder instead.
CSVReader(Reader reader, int line, ICSVParser icsvParser) Deprecated. Please use CSVReaderBuilder instead.

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Closes the underlying reader.
protected String[]	combineResultsFromMultipleReads(String[] buffer, String[] lastRead) For multi-line records this method combines the current result with the result from previous read(s).
long	getLinesRead() Used for debugging purposes, this method returns the number of lines that has been read from the reader passed into the CSVReader.
int	getMultilineLimit() Only useful for tests.
protected String	getNextLine() Reads the next line from the file.
ICSVParser	getParser()
long	getRecordsRead() Used for debugging purposes, this method returns the number of records that has been read from the CSVReader.
int	getSkipLines() Returns the number of lines in the CSV file to skip before processing.
protected boolean	isClosed() Checks to see if the file is closed.
Iterator<String[]>	iterator() Creates an Iterator for processing the CSV data.
boolean	keepCarriageReturns() Returns if the reader will keep carriage returns found in data or remove them.
List<String[]>	readAll() Reads the entire file into a List with each element being a String[] of tokens.
String[]	readNext() Reads the next line from the buffer and converts to a string array.
void	setMultilineLimit(int multilineLimit) Deprecated. Please use CSVReaderBuilder.withMultilineLimit(int) instead.
protected String[]	validateResult(String[] result) Increments the number of records read if the result passed in is not null.
boolean	verifyReader() Returns if the CSVReader will verify the reader before each read.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_KEEP_CR

public static final boolean DEFAULT_KEEP_CR

See Also:

Constant Field Values

DEFAULT_VERIFY_READER

public static final boolean DEFAULT_VERIFY_READER

See Also:

Constant Field Values

DEFAULT_SKIP_LINES

public static final int DEFAULT_SKIP_LINES

The default line to start reading.

See Also:

Constant Field Values

DEFAULT_MULTILINE_LIMIT

public static final int DEFAULT_MULTILINE_LIMIT

The default limit for the number of lines in a multiline record. Less than one means no limit.

See Also:

Constant Field Values

READ_AHEAD_LIMIT

public static final int READ_AHEAD_LIMIT

See Also:

Constant Field Values

parser

protected ICSVParser parser

skipLines

protected int skipLines

br

protected BufferedReader br

lineReader

protected LineReader lineReader

hasNext

protected boolean hasNext

linesSkiped

protected boolean linesSkiped

keepCR

protected boolean keepCR

verifyReader

protected boolean verifyReader

multilineLimit

protected int multilineLimit

errorLocale

protected final Locale errorLocale

linesRead

protected long linesRead

recordsRead

protected long recordsRead

Constructor Detail

CSVReader

public CSVReader(Reader reader)

Constructs CSVReader using defaults for all parameters.

Parameters:

reader - The reader to an underlying CSV source.

CSVReader

@Deprecated
public CSVReader(Reader reader,
                    char separator)

Deprecated. Please use CSVReaderBuilder instead.

Constructs CSVReader with supplied separator.

Parameters:

reader - The reader to an underlying CSV source.

separator - The delimiter to use for separating entries.

CSVReader

@Deprecated
public CSVReader(Reader reader,
                    char separator,
                    char quotechar)

Deprecated. Please use CSVReaderBuilder instead.

Constructs CSVReader with supplied separator and quote char.

Parameters:

reader - The reader to an underlying CSV source.

separator - The delimiter to use for separating entries

quotechar - The character to use for quoted elements

CSVReader

@Deprecated
public CSVReader(Reader reader,
                    char separator,
                    char quotechar,
                    boolean strictQuotes)

Deprecated. Please use CSVReaderBuilder instead.

Constructs CSVReader with supplied separator, quote char, and quote handling behavior.

Parameters:

reader - The reader to an underlying CSV source.

separator - The delimiter to use for separating entries

quotechar - The character to use for quoted elements

strictQuotes - Sets if characters outside the quotes are ignored

CSVReader

@Deprecated
public CSVReader(Reader reader,
                    char separator,
                    char quotechar,
                    char escape)

Deprecated. Please use CSVReaderBuilder instead.

Constructs CSVReader.

Parameters:

reader - The reader to an underlying CSV source.

separator - The delimiter to use for separating entries

quotechar - The character to use for quoted elements

escape - The character to use for escaping a separator or quote

CSVReader

@Deprecated
public CSVReader(Reader reader,
                    char separator,
                    char quotechar,
                    int line)

Deprecated. Please use CSVReaderBuilder instead.

Constructs CSVReader.

Parameters:

reader - The reader to an underlying CSV source.

separator - The delimiter to use for separating entries

quotechar - The character to use for quoted elements

line - The number of lines to skip before reading

CSVReader

@Deprecated
public CSVReader(Reader reader,
                    char separator,
                    char quotechar,
                    char escape,
                    int line)

Deprecated. Please use CSVReaderBuilder instead.

Constructs CSVReader.

Parameters:

reader - The reader to an underlying CSV source.

separator - The delimiter to use for separating entries

quotechar - The character to use for quoted elements

escape - The character to use for escaping a separator or quote

line - The number of lines to skip before reading

CSVReader

@Deprecated
public CSVReader(Reader reader,
                    char separator,
                    char quotechar,
                    char escape,
                    int line,
                    boolean strictQuotes)

Deprecated. Please use CSVReaderBuilder instead.

Constructs CSVReader.

Parameters:

reader - The reader to an underlying CSV source.

separator - The delimiter to use for separating entries

quotechar - The character to use for quoted elements

escape - The character to use for escaping a separator or quote

line - The number of lines to skip before reading

strictQuotes - Sets if characters outside the quotes are ignored

CSVReader

@Deprecated
public CSVReader(Reader reader,
                    char separator,
                    char quotechar,
                    char escape,
                    int line,
                    boolean strictQuotes,
                    boolean ignoreLeadingWhiteSpace)

Deprecated. Please use CSVReaderBuilder instead.

Constructs CSVReader with all data entered.

Parameters:

reader - The reader to an underlying CSV source.

separator - The delimiter to use for separating entries

quotechar - The character to use for quoted elements

escape - The character to use for escaping a separator or quote

line - The number of lines to skip before reading

strictQuotes - Sets if characters outside the quotes are ignored

ignoreLeadingWhiteSpace - If true, parser should ignore white space before a quote in a field

CSVReader

@Deprecated
public CSVReader(Reader reader,
                    char separator,
                    char quotechar,
                    char escape,
                    int line,
                    boolean strictQuotes,
                    boolean ignoreLeadingWhiteSpace,
                    boolean keepCR)

Deprecated. Please use CSVReaderBuilder instead.

Constructs CSVReader with all data entered.

Parameters:

reader - The reader to an underlying CSV source.

separator - The delimiter to use for separating entries

quotechar - The character to use for quoted elements

escape - The character to use for escaping a separator or quote

line - The number of lines to skip before reading

strictQuotes - Sets if characters outside the quotes are ignored

ignoreLeadingWhiteSpace - If true, parser should ignore white space before a quote in a field

keepCR - If true the reader will keep carriage returns, otherwise it will discard them.

CSVReader

@Deprecated
public CSVReader(Reader reader,
                    int line,
                    ICSVParser icsvParser)

Deprecated. Please use CSVReaderBuilder instead.

Constructs CSVReader with supplied CSVParser.

Parameters:

reader - The reader to an underlying CSV source.

line - The number of lines to skip before reading

icsvParser - The parser to use to parse input

Method Detail

getParser

public ICSVParser getParser()

Returns:

The CSVParser used by the reader.

getSkipLines

public int getSkipLines()

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

Returns:

The number of lines in the CSV file to skip before processing.

keepCarriageReturns

public boolean keepCarriageReturns()

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

Returns:

True if reader will keep carriage returns, false otherwise.

readAll

public List<String[]> readAll()
                       throws IOException

Reads the entire file into a List with each element being a String[] of tokens.

Returns:

A List of String[], with each String[] representing a line of the file.

Throws:

IOException - If bad things happen during the read

readNext

public 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, or null if there is no more input.

Throws:

IOException - If bad things happen during the read

validateResult

protected String[] validateResult(String[] result)

Increments the number of records read if the result passed in is not null.

Parameters:

result - The result of the read operation

Returns:

Result that was passed in.

combineResultsFromMultipleReads

protected String[] combineResultsFromMultipleReads(String[] buffer,
                                       String[] lastRead)

For multi-line records this method combines the current result with the result from previous read(s).

Parameters:

buffer - Previous data read for this record

lastRead - Latest data read for this record.

Returns:

String array with union of the buffer and lastRead arrays.

getNextLine

protected String getNextLine()
                      throws IOException

Reads the next line from the file.

Returns:

The next line from the file without trailing newline, or null if there is no more input.

Throws:

IOException - If bad things happen during the read

getMultilineLimit

public int getMultilineLimit()

Only useful for tests.

Returns:

The maximum number of lines allowed in a multiline record.

setMultilineLimit

@Deprecated
public void setMultilineLimit(int multilineLimit)

Deprecated. Please use CSVReaderBuilder.withMultilineLimit(int) instead.

Sets the maximum number of lines allowed in a multiline record. More than this number in one record results in an IOException.

Parameters:

multilineLimit - No more than this number of lines is allowed in a single input record. The default is DEFAULT_MULTILINE_LIMIT.

isClosed

protected boolean isClosed()

Checks to see if the file is closed.

Returns:

True if the reader can no longer be read from.

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

public Iterator<String[]> iterator()

Creates an Iterator for processing the CSV data.

Specified by:

iterator in interface Iterable<String[]>

Returns:

A String[] iterator.

verifyReader

public boolean verifyReader()

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 their ready() methods until a read was done (namely readers created using Channels). This caused opencsv not to read from those readers.

Returns:

True if CSVReader will verify the reader before reads. False otherwise.

Since:

3.3

See Also:

Bug 108

getLinesRead

public long getLinesRead()

Used for debugging purposes, this method returns the number of lines that has been read from the reader passed into the CSVReader.

Given the following data:

 First line in the file
 some other descriptive line
 a,b,c

 a,"b\nb",c
 

With a CSVReader constructed like so:
CSVReader c = builder.withCSVParser(new CSVParser())
.withSkipLines(2)
.build();

The initial call to getLinesRead() will be 0. After the first call to readNext() then getLinesRead() will return 3 (because header was read). After the second call to read the blank line then getLinesRead() will return 4 (still a read). After third call to readNext() getLinesRead() will return 6 because it took two line reads to retrieve this record. Subsequent calls to readNext() (since we are out of data) will not increment the number of lines read.

An example of this is in the linesAndRecordsRead() test in CSVReaderTest.

Returns:

The number of lines read by the reader (including skip lines).

Since:

3.6

See Also:

Feature Request 73

getRecordsRead

public long getRecordsRead()

Used for debugging purposes, this method returns the number of records that has been read from the CSVReader.

Given the following data:

 First line in the file
 some other descriptive line
 a,b,c
 a,"b\nb",c
 

With a CSVReader constructed like so:
CSVReader c = builder.withCSVParser(new CSVParser())
.withSkipLines(2)
.build();

The initial call to getRecordsRead() will be 0. After the first call to readNext() then getRecordsRead() will return 1. After the second call to read the blank line then getRecordsRead() will return 2 (a blank line is considered a record with one empty field). After third call to readNext() getRecordsRead() will return 3 because even though it reads to retrieve this record, it is still a single record read. Subsequent calls to readNext() (since we are out of data) will not increment the number of records read.

An example of this is in the linesAndRecordsRead() test in CSVReaderTest.

Returns:

The number of records (array of Strings[]) read by the reader.

Since:

3.6

See Also:

Feature Request 73