Package org.apache.commons.csv

Class ExtendedBufferedReader

java.lang.Object

java.io.Reader

org.apache.commons.io.input.UnsynchronizedReader

org.apache.commons.io.input.UnsynchronizedBufferedReader

org.apache.commons.csv.ExtendedBufferedReader

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, java.lang.Readable

final class ExtendedBufferedReader
extends org.apache.commons.io.input.UnsynchronizedBufferedReader

A special buffered reader which supports sophisticated read access.

In particular the reader supports a look-ahead option, which allows you to see the next char returned by read(). This reader also tracks how many characters have been read with getPosition().

Field Summary

Fields

Modifier and Type	Field	Description
private long	bytesRead	The number of bytes read so far.
private long	bytesReadMark
private java.nio.charset.CharsetEncoder	encoder	Encoder for calculating the number of bytes for each character read.
private int	lastChar	The last char returned
private int	lastCharMark
private long	lineNumber	The count of EOLs (CR/LF/CRLF) seen so far
private long	lineNumberMark
private long	position	The position, which is the number of characters read so far
private long	positionMark

Fields inherited from class java.io.Reader

lock

Constructor Summary

Constructors

Constructor	Description
ExtendedBufferedReader(java.io.Reader reader)	Constructs a new instance using the default buffer size.
ExtendedBufferedReader(java.io.Reader reader, java.nio.charset.Charset charset, boolean trackBytes)	Constructs a new instance with the specified reader, character set, and byte tracking option.

Method Summary

Modifier and Type	Method	Description
void	close()	Closes the stream.
(package private) long	getBytesRead()	Gets the number of bytes read by the reader.
private int	getEncodedCharLength(int current)	Gets the byte length of the given character based on the the original Unicode specification, which defined characters as fixed-width 16-bit entities.
(package private) int	getLastChar()	Returns the last character that was read as an integer (0 to 65535).
(package private) long	getLineNumber()	Returns the current line number
(package private) long	getPosition()	Gets the character position in the reader.
void	mark(int readAheadLimit)
int	read()
int	read(char[] buf, int offset, int length)
java.lang.String	readLine()	Gets the next line, dropping the line terminator(s).
void	reset()

Methods inherited from class org.apache.commons.io.input.UnsynchronizedBufferedReader

markSupported, peek, peek, ready, skip

Methods inherited from class org.apache.commons.io.input.UnsynchronizedReader

isClosed, setClosed

Methods inherited from class java.io.Reader

read, read

Methods inherited from class java.lang.Object

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

Field Detail

lastChar

private int lastChar

The last char returned

lastCharMark

private int lastCharMark

lineNumber

private long lineNumber

The count of EOLs (CR/LF/CRLF) seen so far

lineNumberMark

private long lineNumberMark

position

private long position

The position, which is the number of characters read so far

positionMark

private long positionMark

bytesRead

private long bytesRead

The number of bytes read so far.

bytesReadMark

private long bytesReadMark

encoder

private final java.nio.charset.CharsetEncoder encoder

Encoder for calculating the number of bytes for each character read.

Constructor Detail

ExtendedBufferedReader

ExtendedBufferedReader(java.io.Reader reader)

Constructs a new instance using the default buffer size.

ExtendedBufferedReader

ExtendedBufferedReader(java.io.Reader reader,
                       java.nio.charset.Charset charset,
                       boolean trackBytes)

Constructs a new instance with the specified reader, character set, and byte tracking option. Initializes an encoder if byte tracking is enabled and a character set is provided.

Parameters:

reader - the reader supports a look-ahead option.

charset - the character set for encoding, or null if not applicable.

trackBytes - true to enable byte tracking; false to disable it.

Method Detail

close

public void close()
           throws java.io.IOException

Closes the stream.

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface java.io.Closeable

Overrides:

close in class org.apache.commons.io.input.UnsynchronizedBufferedReader

Throws:

java.io.IOException - If an I/O error occurs

getBytesRead

long getBytesRead()

Gets the number of bytes read by the reader.

Returns:

the number of bytes read by the read

getEncodedCharLength

private int getEncodedCharLength(int current)
                          throws java.nio.charset.CharacterCodingException

Gets the byte length of the given character based on the the original Unicode specification, which defined characters as fixed-width 16-bit entities.

The Unicode characters are divided into two main ranges:

• U+0000 to U+FFFF (Basic Multilingual Plane, BMP):
  • Represented using a single 16-bit char.
  • Includes UTF-8 encodings of 1-byte, 2-byte, and some 3-byte characters.
• U+10000 to U+10FFFF (Supplementary Characters):
  • Represented as a pair of chars:
  • The first char is from the high-surrogates range (?-?).
  • The second char is from the low-surrogates range (?-?).
  • Includes UTF-8 encodings of some 3-byte characters and all 4-byte characters.

Parameters:

current - the current character to process.

Returns:

the byte length of the character.

Throws:

java.nio.charset.CharacterCodingException - if the character cannot be encoded.

getLastChar

int getLastChar()

Returns the last character that was read as an integer (0 to 65535). This will be the last character returned by any of the read methods. This will not include a character read using the UnsynchronizedBufferedReader.peek() method. If no character has been read then this will return Constants.UNDEFINED. If the end of the stream was reached on the last read then this will return IOUtils.EOF.

Returns:

the last character that was read

getLineNumber

long getLineNumber()

Returns the current line number

Returns:

the current line number

getPosition

long getPosition()

Gets the character position in the reader.

Returns:

the current position in the reader (counting characters, not bytes since this is a Reader)

mark

public void mark(int readAheadLimit)
          throws java.io.IOException

Overrides:

mark in class org.apache.commons.io.input.UnsynchronizedBufferedReader

Throws:

java.io.IOException

read

public int read()
         throws java.io.IOException

Overrides:

read in class org.apache.commons.io.input.UnsynchronizedBufferedReader

Throws:

java.io.IOException

read

public int read(char[] buf,
                int offset,
                int length)
         throws java.io.IOException

Overrides:

read in class org.apache.commons.io.input.UnsynchronizedBufferedReader

Throws:

java.io.IOException

readLine

public java.lang.String readLine()
                          throws java.io.IOException

Gets the next line, dropping the line terminator(s). This method should only be called when processing a comment, otherwise, information can be lost.

Increments lineNumber and updates position.

Sets lastChar to Constants.EOF at EOF, otherwise the last EOL character.

Overrides:

readLine in class org.apache.commons.io.input.UnsynchronizedBufferedReader

Returns:

the line that was read, or null if reached EOF.

Throws:

java.io.IOException

reset

public void reset()
           throws java.io.IOException

Overrides:

reset in class org.apache.commons.io.input.UnsynchronizedBufferedReader

Throws:

java.io.IOException