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:
Closeable, AutoCloseable, 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 final 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 Reader

    lock

  • Constructor Summary

    Constructors
    Constructor
    Description
    ExtendedBufferedReader(Reader reader)
    Constructs a new instance using the default buffer size.
    ExtendedBufferedReader(Reader reader, 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)
     
    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 Reader

    read, read

    Methods inherited from class Object

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

  • Field Details

    • 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 CharsetEncoder encoder
      Encoder for calculating the number of bytes for each character read.

  • Constructor Details

    • ExtendedBufferedReader

      ExtendedBufferedReader(Reader reader)
      Constructs a new instance using the default buffer size.

    • ExtendedBufferedReader

      ExtendedBufferedReader(Reader reader, 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 Details

    • close

      public void close() throws IOException
      Closes the stream.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Overrides:
      close in class org.apache.commons.io.input.UnsynchronizedBufferedReader
      Throws:
      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 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:
      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 IOException
      Overrides:
      mark in class org.apache.commons.io.input.UnsynchronizedBufferedReader
      Throws:
      IOException

    • read

      public int read() throws IOException
      Overrides:
      read in class org.apache.commons.io.input.UnsynchronizedBufferedReader
      Throws:
      IOException

    • read

      public int read(char[] buf, int offset, int length) throws IOException
      Overrides:
      read in class org.apache.commons.io.input.UnsynchronizedBufferedReader
      Throws:
      IOException

    • readLine

      public String readLine() throws 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:
      IOException

    • reset

      public void reset() throws IOException
      Overrides:
      reset in class org.apache.commons.io.input.UnsynchronizedBufferedReader
      Throws:
      IOException