LineNumberReader

public class LineNumberReader extends BufferedReader

A buffered character-input stream that keeps track of line numbers. This class defines methods setLineNumber(int) and getLineNumber() for setting and getting the current line number respectively.

By default, line numbering begins at 0. This number increments at every line terminator as the data is read, and can be changed with a call to setLineNumber(int). Note however, that setLineNumber(int) does not actually change the current position in the stream; it only changes the value that will be returned by getLineNumber().

A line is considered to be terminated by any one of a line feed ('\n'), a carriage return ('\r'), or a carriage return followed immediately by a linefeed.

Inherited Field Summary

From class java.io.Reader

protected Object

lock

The object used to synchronize operations on this stream.

Public Constructor Summary

	LineNumberReader(Reader in) Create a new line-numbering reader, using the default input-buffer size.
	LineNumberReader(Reader in, int sz) Create a new line-numbering reader, reading characters into a buffer of the given size.

Public Method Summary

int	getLineNumber() Get the current line number.
void	mark(int readAheadLimit) Mark the present position in the stream.
int	read() Read a single character.
int	read(char[] cbuf, int off, int len) Read characters into a portion of an array.
String	readLine() Read a line of text.
void	reset() Reset the stream to the most recent mark.
void	setLineNumber(int lineNumber) Set the current line number.
long	skip(long n) Skip characters.

Inherited Method Summary

From class java.io.BufferedReader

void	close() Closes the stream and releases any system resources associated with it.
Stream<String>	lines() Returns a Stream, the elements of which are lines read from this BufferedReader.
void	mark(int readAheadLimit) Marks the present position in the stream.
boolean	markSupported() Tells whether this stream supports the mark() operation, which it does.
int	read() Reads a single character.
int	read(char[] cbuf, int off, int len) Reads characters into a portion of an array.
String	readLine() Reads a line of text.
boolean	ready() Tells whether this stream is ready to be read.
void	reset() Resets the stream to the most recent mark.
long	skip(long n) Skips characters.

From class java.io.Reader

abstract void	close() Closes the stream and releases any system resources associated with it.
void	mark(int readAheadLimit) Marks the present position in the stream.
boolean	markSupported() Tells whether this stream supports the mark() operation.
int	read() Reads a single character.
abstract int	read(char[] cbuf, int off, int len) Reads characters into a portion of an array.
int	read(char[] cbuf) Reads characters into an array.
int	read(CharBuffer target) Attempts to read characters into the specified character buffer.
boolean	ready() Tells whether this stream is ready to be read.
void	reset() Resets the stream.
long	skip(long n) Skips characters.

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of Class that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

From interface java.lang.Readable

abstract int

read(CharBuffer cb) Attempts to read characters into the specified character buffer.

From interface java.io.Closeable

abstract void

close() Closes this stream and releases any system resources associated with it.

From interface java.lang.AutoCloseable

abstract void

close() Closes this resource, relinquishing any underlying resources.

Public Constructors

public LineNumberReader (Reader in)

Create a new line-numbering reader, using the default input-buffer size.

Parameters

in	A Reader object to provide the underlying stream

public LineNumberReader (Reader in, int sz)

Create a new line-numbering reader, reading characters into a buffer of the given size.

Parameters

in	A Reader object to provide the underlying stream
sz	An int specifying the size of the buffer

Public Methods

public int getLineNumber ()

Get the current line number.

Returns

• The current line number

See Also

• setLineNumber(int)

public void mark (int readAheadLimit)

Mark the present position in the stream. Subsequent calls to reset() will attempt to reposition the stream to this point, and will also reset the line number appropriately.

Parameters

readAheadLimit	Limit on the number of characters that may be read while still preserving the mark. After reading this many characters, attempting to reset the stream may fail.

Throws

IOException	If an I/O error occurs

public int read ()

Read a single character. Line terminators are compressed into single newline ('\n') characters. Whenever a line terminator is read the current line number is incremented.

Returns

• The character read, or -1 if the end of the stream has been reached

Throws

IOException	If an I/O error occurs

public int read (char[] cbuf, int off, int len)

Read characters into a portion of an array. Whenever a line terminator is read the current line number is incremented.

Parameters

cbuf	Destination buffer
off	Offset at which to start storing characters
len	Maximum number of characters to read

Returns

• The number of bytes read, or -1 if the end of the stream has already been reached

Throws

IOException	If an I/O error occurs

public String readLine ()

Read a line of text. Whenever a line terminator is read the current line number is incremented.

Returns

• A String containing the contents of the line, not including any line termination characters, or null if the end of the stream has been reached

Throws

IOException	If an I/O error occurs

public void reset ()

Reset the stream to the most recent mark.

Throws

IOException	If the stream has not been marked, or if the mark has been invalidated

public void setLineNumber (int lineNumber)

Set the current line number.

Parameters

lineNumber	An int specifying the line number

See Also

• getLineNumber()

public long skip (long n)

Skip characters.

Parameters

n	The number of characters to skip

Returns

• The number of characters actually skipped

Throws

IOException	If an I/O error occurs
IllegalArgumentException	If n is negative