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.
lock
public LineNumberReader(Reader in)
Create a new line-numbering reader, using the default input-buffer size.
in
- A Reader object to provide the underlying streampublic LineNumberReader(Reader in, int sz)
Create a new line-numbering reader, reading characters into a buffer of the given size.
in
- A Reader object to provide the underlying streamsz
- An int specifying the size of the bufferpublic void setLineNumber(int lineNumber)
Set the current line number.
lineNumber
- An int specifying the line numbergetLineNumber()
public int getLineNumber()
Get the current line number.
setLineNumber(int)
public int read() throws IOException
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.
read
in class BufferedReader
IOException
- If an I/O error occurspublic int read(char[] cbuf, int off, int len) throws IOException
Read characters into a portion of an array. Whenever a line terminator is read the current line number is incremented.
read
in class BufferedReader
cbuf
- Destination bufferoff
- Offset at which to start storing characterslen
- Maximum number of characters to readIOException
- If an I/O error occurspublic String readLine() throws IOException
Read a line of text. Whenever a line terminator is read the current line number is incremented.
readLine
in class BufferedReader
null
if the end of the stream has been reachedIOException
- If an I/O error occursFiles.readAllLines(java.nio.file.Path, java.nio.charset.Charset)
public long skip(long n) throws IOException
Skip characters.
skip
in class BufferedReader
n
- The number of characters to skipIOException
- If an I/O error occursIllegalArgumentException
- If n
is negativepublic void mark(int readAheadLimit) throws IOException
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.
mark
in class BufferedReader
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.IOException
- If an I/O error occurspublic void reset() throws IOException
Reset the stream to the most recent mark.
reset
in class BufferedReader
IOException
- If the stream has not been marked, or if the mark has been invalidated
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
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