java.io
Class LineNumberReader
- Closeable, Readable
This class functions like a standard
Reader
except that it
counts line numbers, and canonicalizes newline characters. As data
is read, whenever the char sequences "\r", "\n", or "\r\n" are encountered,
the running line count is incremeted by one. Additionally, the whatever
line termination sequence was encountered will be converted to a "\n"
char. Note that this class numbers lines from 0. When the first
line terminator is encountered, the line number is incremented to 1, and
so on. Also note that actual "\r" and "\n" characters are looked for.
The system dependent line separator sequence is ignored.
This class counts only line termination characters. If the last line
read from the stream does not end in a line termination sequence, it
will not be counted as a line.
LineNumberReader(Reader in) - Create a new
LineNumberReader that reads from the
specified subordinate Reader .
|
LineNumberReader(Reader in, int size) - This method initializes a new
LineNumberReader to read
from the specified subordinate Reader using the specified
read buffer size.
|
int | getLineNumber() - This method returns the current line number
|
void | mark(int readLimit) - This method marks a position in the input to which the stream can be
"reset" char calling the
reset() method.
|
int | read() - This method reads an unsigned char from the input stream and returns it
as an int in the range of 0-65535.
|
int | read(char[] buf, int offset, int count) - This method reads chars from a stream and stores them into a caller
supplied buffer.
|
String | readLine() - This method reads a line of text from the input stream and returns
it as a
String .
|
void | reset() - This method resets a stream to the point where the
mark()
method
was called.
|
void | setLineNumber(int lineNumber) - This method sets the current line number to the specified value.
|
long | skip(long count) - This method skips over characters in the stream.
|
clone , equals , extends Object> getClass , finalize , hashCode , notify , notifyAll , toString , wait , wait , wait |
LineNumberReader
public LineNumberReader(Reader in)
Create a new LineNumberReader
that reads from the
specified subordinate Reader
. A default 8K char sized
buffer will be used for reads.
in
- The subordinate Reader
to read from
LineNumberReader
public LineNumberReader(Reader in,
int size)
This method initializes a new LineNumberReader
to read
from the specified subordinate Reader
using the specified
read buffer size.
in
- The subordinate Reader
to read fromsize
- The buffer size to use for reading
getLineNumber
public int getLineNumber()
This method returns the current line number
mark
public void mark(int readLimit)
throws IOException
This method marks a position in the input to which the stream can be
"reset" char calling the
reset()
method. The parameter
readlimit
is the number of chars that can be read from the
stream after setting the mark before the mark becomes invalid. For
example, if
mark()
is called with a read limit of 10,
then when
11 chars of data are read from the stream before the
reset()
method is called, then the mark is invalid and the stream object
instance is not required to remember the mark.
In this class, this method will remember the current line number as well
as the current position in the stream. When the
reset()
method
is called, the line number will be restored to the saved line number in
addition to the stream position.
- mark in interface BufferedReader
readLimit
- The number of chars that can be read before the
mark becomes invalid
read
public int read()
throws IOException
This method reads an unsigned char from the input stream and returns it
as an int in the range of 0-65535. This method will return -1 if the
end of the stream has been reached.
Note that if a line termination sequence is encountered (ie, "\r",
"\n", or "\r\n") then that line termination sequence is converted to
a single "\n" value which is returned from this method. This means
that it is possible this method reads two chars from the subordinate
stream instead of just one.
Note that this method will block until a char of data is available
to be read.
- read in interface BufferedReader
- The char read or -1 if end of stream
read
public int read(char[] buf,
int offset,
int count)
throws IOException
This method reads chars from a stream and stores them into a caller
supplied buffer. It starts storing data at index
offset
into
the buffer and attemps to read
len
chars. This method can
return before reading the number of chars requested. The actual number
of chars read is returned as an int. A -1 is returned to indicated the
end of the stream.
This method will block until some data can be read.
Note that if a line termination sequence is encountered (ie, "\r",
"\n", or "\r\n") then that line termination sequence is converted to
a single "\n" value which is stored in the buffer. Only a single
char is counted towards the number of chars read in this case.
- read in interface BufferedReader
buf
- The array into which the chars read should be storedoffset
- The offset into the array to start storing charscount
- The requested number of chars to read
- The actual number of chars read, or -1 if end of stream
readLine
public String readLine()
throws IOException
This method reads a line of text from the input stream and returns
it as a String
. A line is considered to be terminated
by a "\r", "\n", or "\r\n" sequence, not by the system dependent line
separator.
- readLine in interface BufferedReader
- The line read as a
String
or null
if end of stream.
reset
public void reset()
throws IOException
This method resets a stream to the point where the
mark()
method
was called. Any chars that were read after the mark point was set will
be re-read during subsequent reads.
In this class, this method will also restore the line number that was
current when the
mark()
method was called.
- reset in interface BufferedReader
setLineNumber
public void setLineNumber(int lineNumber)
This method sets the current line number to the specified value.
lineNumber
- The new line number
skip
public long skip(long count)
throws IOException
This method skips over characters in the stream. This method will
skip the specified number of characters if possible, but is not required
to skip them all. The actual number of characters skipped is returned.
This method returns 0 if the specified number of chars is less than 1.
- skip in interface BufferedReader
count
- The specified number of chars to skip.
- The actual number of chars skipped.
LineNumberReader.java -- A character input stream which counts line numbers
Copyright (C) 1998, 1999, 2001, 2003, 2005 Free Software Foundation, Inc.
This file is part of GNU Classpath.
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