File	Doc	Category	Size	Date	Package
LineNumberReader.java	API Doc	Java SE 5 API	6723	Fri Aug 26 14:57:00 BST 2005	java.io

LineNumberReader

• java.lang.Object
  • java.io.Reader
    • java.io.BufferedReader

Fields Summary
private int	lineNumber The current line number
private int	markedLineNumber The line number of the mark, if any
private boolean	skipLF If the next character is a line feed, skip it
private boolean	markedSkipLF The skipLF flag when the mark was set
private static final int	maxSkipBufferSize Maximum skip-buffer size
private char[]	skipBuffer Skip buffer, null until allocated

Constructors Summary
public LineNumberReader(Reader in) Create a new line-numbering reader, using the default input-buffer size. param in a Reader object to provide the underlying stream. super(in);
public LineNumberReader(Reader in, int sz) Create a new line-numbering reader, reading characters into a buffer of the given size. param in a Reader object to provide the underlying stream. param sz an int specifying the size of the buffer. super(in, sz);

Methods Summary
public int	getLineNumber() Get the current line number. return The current line number. see #setLineNumber return lineNumber;
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. param 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. exception IOException If an I/O error occurs synchronized (lock) { super.mark(readAheadLimit); markedLineNumber = lineNumber; markedSkipLF = skipLF; }
public int	read() Read a single character. Line terminators are compressed into single newline ('\n') characters. return The character read, or -1 if the end of the stream has been reached exception IOException If an I/O error occurs synchronized (lock) { int c = super.read(); if (skipLF) { if (c == '\n") c = super.read(); skipLF = false; } switch (c) { case '\r": skipLF = true; case '\n": /* Fall through */ lineNumber++; return '\n"; } return c; }
public int	read(char[] cbuf, int off, int len) Read characters into a portion of an array. param cbuf Destination buffer param off Offset at which to start storing characters param len Maximum number of characters to read return The number of bytes read, or -1 if the end of the stream has already been reached exception IOException If an I/O error occurs synchronized (lock) { int n = super.read(cbuf, off, len); for (int i = off; i < off + n; i++) { int c = cbuf[i]; if (skipLF) { skipLF = false; if (c == '\n") continue; } switch (c) { case '\r": skipLF = true; case '\n": /* Fall through */ lineNumber++; break; } } return n; }
public java.lang.String	readLine() Read a line of text. 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. return 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 exception IOException If an I/O error occurs synchronized (lock) { String l = super.readLine(skipLF); skipLF = false; if (l != null) lineNumber++; return l; }
public void	reset() Reset the stream to the most recent mark. exception IOException If the stream has not been marked, or if the mark has been invalidated synchronized (lock) { super.reset(); lineNumber = markedLineNumber; skipLF = markedSkipLF; }
public void	setLineNumber(int lineNumber) Set the current line number. param lineNumber an int specifying the line number. see #getLineNumber this.lineNumber = lineNumber;
public long	skip(long n) Skip characters. param n The number of characters to skip return The number of characters actually skipped exception IOException If an I/O error occurs exception IllegalArgumentException if n is negative if (n < 0) throw new IllegalArgumentException("skip() value is negative"); int nn = (int) Math.min(n, maxSkipBufferSize); synchronized (lock) { if ((skipBuffer == null) || (skipBuffer.length < nn)) skipBuffer = new char[nn]; long r = n; while (r > 0) { int nc = read(skipBuffer, 0, (int) Math.min(r, nn)); if (nc == -1) break; r -= nc; } return n - r; }