| /* |
| * Copyright (c) 1996, 2006, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package java.io; |
| |
| |
| /** |
| * A buffered character-input stream that keeps track of line numbers. This |
| * class defines methods {@link #setLineNumber(int)} and {@link |
| * #getLineNumber()} for setting and getting the current line number |
| * respectively. |
| * |
| * <p> By default, line numbering begins at 0. This number increments at every |
| * <a href="#lt">line terminator</a> as the data is read, and can be changed |
| * with a call to <tt>setLineNumber(int)</tt>. Note however, that |
| * <tt>setLineNumber(int)</tt> does not actually change the current position in |
| * the stream; it only changes the value that will be returned by |
| * <tt>getLineNumber()</tt>. |
| * |
| * <p> A line is considered to be <a name="lt">terminated</a> by any one of a |
| * line feed ('\n'), a carriage return ('\r'), or a carriage return followed |
| * immediately by a linefeed. |
| * |
| * @author Mark Reinhold |
| * @since JDK1.1 |
| */ |
| |
| public class LineNumberReader extends BufferedReader { |
| |
| /** The current line number */ |
| private int lineNumber = 0; |
| |
| /** The line number of the mark, if any */ |
| private int markedLineNumber; // Defaults to 0 |
| |
| /** If the next character is a line feed, skip it */ |
| private boolean skipLF; |
| |
| /** The skipLF flag when the mark was set */ |
| private boolean markedSkipLF; |
| |
| /** |
| * Create a new line-numbering reader, using the default input-buffer |
| * size. |
| * |
| * @param in |
| * A Reader object to provide the underlying stream |
| */ |
| public LineNumberReader(Reader in) { |
| super(in); |
| } |
| |
| /** |
| * 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 |
| */ |
| public LineNumberReader(Reader in, int sz) { |
| super(in, sz); |
| } |
| |
| /** |
| * Set the current line number. |
| * |
| * @param lineNumber |
| * An int specifying the line number |
| * |
| * @see #getLineNumber |
| */ |
| public void setLineNumber(int lineNumber) { |
| this.lineNumber = lineNumber; |
| } |
| |
| /** |
| * Get the current line number. |
| * |
| * @return The current line number |
| * |
| * @see #setLineNumber |
| */ |
| public int getLineNumber() { |
| return lineNumber; |
| } |
| |
| /** |
| * Read a single character. <a href="#lt">Line terminators</a> are |
| * compressed into single newline ('\n') characters. Whenever a line |
| * terminator is read the current line number is incremented. |
| * |
| * @return The character read, or -1 if the end of the stream has been |
| * reached |
| * |
| * @throws IOException |
| * If an I/O error occurs |
| */ |
| public int read() throws IOException { |
| 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; |
| } |
| } |
| |
| /** |
| * Read characters into a portion of an array. Whenever a <a |
| * href="#lt">line terminator</a> is read the current line number is |
| * incremented. |
| * |
| * @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 |
| * |
| * @throws IOException |
| * If an I/O error occurs |
| */ |
| public int read(char cbuf[], int off, int len) throws IOException { |
| 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; |
| } |
| } |
| |
| /** |
| * Read a line of text. Whenever a <a href="#lt">line terminator</a> is |
| * read the current line number is incremented. |
| * |
| * @return A String containing the contents of the line, not including |
| * any <a href="#lt">line termination characters</a>, or |
| * <tt>null</tt> if the end of the stream has been reached |
| * |
| * @throws IOException |
| * If an I/O error occurs |
| */ |
| public String readLine() throws IOException { |
| synchronized (lock) { |
| String l = super.readLine(skipLF); |
| skipLF = false; |
| if (l != null) |
| lineNumber++; |
| return l; |
| } |
| } |
| |
| /** Maximum skip-buffer size */ |
| private static final int maxSkipBufferSize = 8192; |
| |
| /** Skip buffer, null until allocated */ |
| private char skipBuffer[] = null; |
| |
| /** |
| * Skip characters. |
| * |
| * @param n |
| * The number of characters to skip |
| * |
| * @return The number of characters actually skipped |
| * |
| * @throws IOException |
| * If an I/O error occurs |
| * |
| * @throws IllegalArgumentException |
| * If <tt>n</tt> is negative |
| */ |
| public long skip(long n) throws IOException { |
| 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; |
| } |
| } |
| |
| /** |
| * 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. |
| * |
| * @throws IOException |
| * If an I/O error occurs |
| */ |
| public void mark(int readAheadLimit) throws IOException { |
| synchronized (lock) { |
| super.mark(readAheadLimit); |
| markedLineNumber = lineNumber; |
| markedSkipLF = skipLF; |
| } |
| } |
| |
| /** |
| * Reset the stream to the most recent mark. |
| * |
| * @throws IOException |
| * If the stream has not been marked, or if the mark has been |
| * invalidated |
| */ |
| public void reset() throws IOException { |
| synchronized (lock) { |
| super.reset(); |
| lineNumber = markedLineNumber; |
| skipLF = markedSkipLF; |
| } |
| } |
| |
| } |
