| career | drupal | java | mac | mysql | perl | scala | uml | unix  

What this is

This file is included in the "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Other links

The source code

 *  gnu/regexp/
 *  Copyright (C) 1998-2001 Wes Biggs
 *  This library is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published
 *  by the Free Software Foundation; either version 2.1 of the License, or
 *  (at your option) any later version.
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  GNU Lesser General Public License for more details.
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

package gnu.regexp;

 * Replaces instances of a given RE found within an InputStream
 * with replacement text.   The replacements are interpolated into the
 * stream when a match is found.
 * @author Wes Biggs
 * @deprecated This class cannot properly handle all character
 *             encodings.  For proper handling, use the REFilterReader
 *             class instead.

public class REFilterInputStream extends FilterInputStream {

    private RE expr;
    private String replace;
    private String buffer;
    private int bufpos;
    private int offset;
    private CharIndexedInputStream stream;

   * Creates an REFilterInputStream.  When reading from this stream,
   * occurrences of patterns matching the supplied regular expression
   * will be replaced with the supplied replacement text (the
   * metacharacters $0 through $9 may be used to refer to the full
   * match or subexpression matches).
   * @param stream The InputStream to be filtered.
   * @param expr The regular expression to search for.
   * @param replace The text pattern to replace matches with.  
  public REFilterInputStream(InputStream stream, RE expr, String replace) {
    super(stream); = new CharIndexedInputStream(stream,0);
    this.expr = expr;
    this.replace = replace;

   * Reads the next byte from the stream per the general contract of
   *  Returns -1 on error or end of stream.
  public int read() {
    // If we have buffered replace data, use it.
    if ((buffer != null) && (bufpos < buffer.length())) {
      return (int) buffer.charAt(bufpos++);

    // check if input is at a valid position
    if (!stream.isValid()) return -1;

    REMatch mymatch = new REMatch(expr.getNumSubs(),offset,0);
    if (expr.match(stream, mymatch)) {
      mymatch.end[0] = mymatch.index;
      offset += mymatch.toString().length();
      buffer = mymatch.substituteInto(replace);
      bufpos = 1;

      // This is prone to infinite loops if replace string turns out empty.
      if (buffer.length() > 0) {
	  return buffer.charAt(0);
    char ch = stream.charAt(0);
    if (ch == CharIndexed.OUT_OF_BOUNDS) return -1;
    return ch;

   * Returns false.  REFilterInputStream does not support mark() and
   * reset() methods. 
  public boolean markSupported() {
    return false;

  /** Reads from the stream into the provided array. */
  public int read(byte[] b, int off, int len) {
    int i;
    int ok = 0;
    while (len-- > 0) {
      i = read();
      if (i == -1) return (ok == 0) ? -1 : ok;
      b[off++] = (byte) i;
    return ok;

  /** Reads from the stream into the provided array. */
  public int read(byte[] b) {
    return read(b,0,b.length);
... this post is sponsored by my books ...

#1 New Release!

FP Best Seller


new blog posts


Copyright 1998-2021 Alvin Alexander,
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.