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.
Summary
Inherited fields |
From class
java.io.Reader
protected
Object |
lock
The object used to synchronize operations on this stream.
|
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Public constructors |
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 methods |
int
|
getLineNumber()
Get the current line number.
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void
|
mark(int readAheadLimit)
Mark the present position in the stream.
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int
|
read()
Read a single character.
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int
|
read(char[] cbuf, int off, int len)
Read characters into a portion of an array.
|
String
|
readLine()
Read a line of text.
|
void
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reset()
Reset the stream to the most recent mark.
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void
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setLineNumber(int lineNumber)
Set the current line number.
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long
|
skip(long n)
Skip characters.
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Inherited methods |
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
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mark(int readAheadLimit)
Marks the present position in the stream.
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boolean
|
markSupported()
Tells whether this stream supports the mark() operation, which it does.
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int
|
read()
Reads a single character.
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int
|
read(char[] cbuf, int off, int len)
Reads characters into a portion of an array.
|
String
|
readLine()
Reads a line of text.
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boolean
|
ready()
Tells whether this stream is ready to be read.
|
void
|
reset()
Resets the stream to the most recent mark.
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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.
|
static
Reader
|
nullReader()
Returns a new Reader that reads no characters.
|
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.
|
long
|
transferTo(Writer out)
Reads all characters from this reader and writes the characters to the
given writer in the order that they are read.
|
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From class
java.lang.Object
Object
|
clone()
Creates and returns a copy of this object.
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boolean
|
equals(Object obj)
Indicates whether some other object is "equal to" this one.
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void
|
finalize()
Called by the garbage collector on an object when garbage collection
determines that there are no more references to the object.
|
final
Class<?>
|
getClass()
Returns the runtime class of this Object .
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int
|
hashCode()
Returns a hash code value for the object.
|
final
void
|
notify()
Wakes up a single thread that is waiting on this object's
monitor.
|
final
void
|
notifyAll()
Wakes up all threads that are waiting on this object's monitor.
|
String
|
toString()
Returns a string representation of the object.
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final
void
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wait(long timeoutMillis, int nanos)
Causes the current thread to wait until it is awakened, typically
by being notified or interrupted, or until a
certain amount of real time has elapsed.
|
final
void
|
wait(long timeoutMillis)
Causes the current thread to wait until it is awakened, typically
by being notified or interrupted, or until a
certain amount of real time has elapsed.
|
final
void
|
wait()
Causes the current thread to wait until it is awakened, typically
by being notified or interrupted.
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|
From interface
java.io.Closeable
abstract
void
|
close()
Closes this stream and releases any system resources associated
with it.
|
|
From interface
java.lang.Readable
abstract
int
|
read(CharBuffer cb)
Attempts to read characters into the specified character buffer.
|
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From interface
java.lang.AutoCloseable
abstract
void
|
close()
Closes this resource, relinquishing any underlying resources.
|
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Public constructors
LineNumberReader
public LineNumberReader (Reader in)
Create a new line-numbering reader, using the default input-buffer
size.
Parameters |
in |
Reader : A Reader object to provide the underlying stream |
LineNumberReader
public LineNumberReader (Reader in,
int sz)
Create a new line-numbering reader, reading characters into a buffer of
the given size.
Parameters |
in |
Reader : A Reader object to provide the underlying stream |
sz |
int : An int specifying the size of the buffer |
Public methods
getLineNumber
public int getLineNumber ()
Get the current line number.
Returns |
int |
The current line number |
mark
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 |
int : 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. |
read
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 |
int |
The character read, or -1 if the end of the stream has been
reached |
read
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 |
char : Destination buffer |
off |
int : Offset at which to start storing characters |
len |
int : Maximum number of characters to read |
Returns |
int |
The number of bytes read, or -1 if the end of the stream has
already been reached |
readLine
public String readLine ()
Read a line of text. Whenever a line terminator is
read the current line number is incremented.
reset
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 |
setLineNumber
public void setLineNumber (int lineNumber)
Set the current line number.
Parameters |
lineNumber |
int : An int specifying the line number |
skip
public long skip (long n)
Skip characters.
Parameters |
n |
long : The number of characters to skip |
Returns |
long |
The number of characters actually skipped |