141 lines
4.7 KiB
Java
141 lines
4.7 KiB
Java
/* gnu/regexp/REFilterInputStream.java
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Copyright (C) 1998-2001, 2004 Free Software Foundation, Inc.
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This file is part of GNU Classpath.
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GNU Classpath is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU Classpath is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU Classpath; see the file COPYING. If not, write to the
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Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA.
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Linking this library statically or dynamically with other modules is
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making a combined work based on this library. Thus, the terms and
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conditions of the GNU General Public License cover the whole
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combination.
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As a special exception, the copyright holders of this library give you
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permission to link this library with independent modules to produce an
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executable, regardless of the license terms of these independent
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modules, and to copy and distribute the resulting executable under
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terms of your choice, provided that you also meet, for each linked
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independent module, the terms and conditions of the license of that
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module. An independent module is a module which is not derived from
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or based on this library. If you modify this library, you may extend
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this exception to your version of the library, but you are not
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obligated to do so. If you do not wish to do so, delete this
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exception statement from your version. */
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package gnu.regexp;
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import java.io.FilterInputStream;
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import java.io.InputStream;
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/**
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* Replaces instances of a given RE found within an InputStream
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* with replacement text. The replacements are interpolated into the
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* stream when a match is found.
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*
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* @author <A HREF="mailto:wes@cacas.org">Wes Biggs</A>
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* @deprecated This class cannot properly handle all character
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* encodings. For proper handling, use the REFilterReader
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* class instead.
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*/
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public class REFilterInputStream extends FilterInputStream {
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private RE expr;
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private String replace;
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private String buffer;
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private int bufpos;
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private int offset;
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private CharIndexedInputStream stream;
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/**
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* Creates an REFilterInputStream. When reading from this stream,
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* occurrences of patterns matching the supplied regular expression
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* will be replaced with the supplied replacement text (the
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* metacharacters $0 through $9 may be used to refer to the full
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* match or subexpression matches).
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*
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* @param stream The InputStream to be filtered.
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* @param expr The regular expression to search for.
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* @param replace The text pattern to replace matches with.
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*/
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public REFilterInputStream(InputStream stream, RE expr, String replace) {
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super(stream);
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this.stream = new CharIndexedInputStream(stream,0);
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this.expr = expr;
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this.replace = replace;
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}
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/**
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* Reads the next byte from the stream per the general contract of
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* InputStream.read(). Returns -1 on error or end of stream.
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*/
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public int read() {
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// If we have buffered replace data, use it.
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if ((buffer != null) && (bufpos < buffer.length())) {
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return (int) buffer.charAt(bufpos++);
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}
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// check if input is at a valid position
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if (!stream.isValid()) return -1;
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REMatch mymatch = new REMatch(expr.getNumSubs(),offset,0);
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if (expr.match(stream, mymatch)) {
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mymatch.end[0] = mymatch.index;
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mymatch.finish(stream);
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stream.move(mymatch.toString().length());
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offset += mymatch.toString().length();
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buffer = mymatch.substituteInto(replace);
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bufpos = 1;
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// This is prone to infinite loops if replace string turns out empty.
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if (buffer.length() > 0) {
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return buffer.charAt(0);
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}
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}
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char ch = stream.charAt(0);
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if (ch == CharIndexed.OUT_OF_BOUNDS) return -1;
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stream.move(1);
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offset++;
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return ch;
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}
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/**
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* Returns false. REFilterInputStream does not support mark() and
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* reset() methods.
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*/
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public boolean markSupported() {
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return false;
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}
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/** Reads from the stream into the provided array. */
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public int read(byte[] b, int off, int len) {
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int i;
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int ok = 0;
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while (len-- > 0) {
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i = read();
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if (i == -1) return (ok == 0) ? -1 : ok;
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b[off++] = (byte) i;
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ok++;
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}
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return ok;
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}
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/** Reads from the stream into the provided array. */
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public int read(byte[] b) {
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return read(b,0,b.length);
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}
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}
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