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LineNumberReader class

java.lang.Object

java.io.Reader

java.io.BufferedReader

java.io.LineNumberReader

A buffered character-input stream that keeps track of line numbers.

LineNumberReader has setLineNumber(int) and getLineNumber() for setting and getting the current line number respectively. By default, line numbering begins at 0.

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.

Return	Return	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. The character read, or -1 if the end of the stream has been reached
int	read(char[] cbuf, int off, int len)	Read characters into a portion of an array. The character read, or -1 if the end of the stream has been reached
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.

Revised from Open JDK source code


import java.io.FileReader;
import java.io.LineNumberReader;

public class Main {
  public static void main(String[] args) throws Exception {
    LineNumberReader lnr = null;

    FileReader fr = new FileReader("c:/a.htm");
    lnr = new LineNumberReader(fr);

    String s;
    while ((s = lnr.readLine()) != null)
      System.out.println(lnr.getLineNumber() + ": " + s);
  }
}

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