| /* |
| * The Apache Software License, Version 1.1 |
| * |
| * Copyright (c) 2002 The Apache Software Foundation. All rights |
| * reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * 3. The end-user documentation included with the redistribution, if |
| * any, must include the following acknowlegement: |
| * "This product includes software developed by the |
| * Apache Software Foundation (http://www.apache.org/)." |
| * Alternately, this acknowlegement may appear in the software itself, |
| * if and wherever such third-party acknowlegements normally appear. |
| * |
| * 4. The names "The Jakarta Project", "Ant", and "Apache Software |
| * Foundation" must not be used to endorse or promote products derived |
| * from this software without prior written permission. For written |
| * permission, please contact apache@apache.org. |
| * |
| * 5. Products derived from this software may not be called "Apache" |
| * nor may "Apache" appear in their names without prior written |
| * permission of the Apache Group. |
| * |
| * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR |
| * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
| * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation. For more |
| * information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| */ |
| package org.apache.tools.ant.filters; |
| |
| import java.io.IOException; |
| import java.io.Reader; |
| |
| /** |
| * This is a Java comment and string stripper reader that filters |
| * those lexical tokens out for purposes of simple Java parsing. |
| * (if you have more complex Java parsing needs, use a real lexer). |
| * Since this class heavily relies on the single char read function, |
| * you are reccomended to make it work on top of a buffered reader. |
| */ |
| public final class StripJavaComments |
| extends BaseFilterReader |
| implements ChainableReader { |
| |
| /** |
| * The read-ahead character, used for effectively pushing a single |
| * character back. -1 indicates that no character is in the buffer. |
| */ |
| private int readAheadCh = -1; |
| |
| /** |
| * Whether or not the parser is currently in the middle of a string |
| * literal. |
| */ |
| private boolean inString = false; |
| |
| /** |
| * Constructor for "dummy" instances. |
| * |
| * @see BaseFilterReader#BaseFilterReader() |
| */ |
| public StripJavaComments() { |
| super(); |
| } |
| |
| /** |
| * Creates a new filtered reader. |
| * |
| * @param in A Reader object providing the underlying stream. |
| * Must not be <code>null</code>. |
| */ |
| public StripJavaComments(final Reader in) { |
| super(in); |
| } |
| |
| /** |
| * Returns the next character in the filtered stream, not including |
| * Java comments. |
| * |
| * @return the next character in the resulting stream, or -1 |
| * if the end of the resulting stream has been reached |
| * |
| * @exception IOException if the underlying stream throws an IOException |
| * during reading |
| */ |
| public final int read() throws IOException { |
| int ch = -1; |
| if (readAheadCh != -1) { |
| ch = readAheadCh; |
| readAheadCh = -1; |
| } else { |
| ch = in.read(); |
| if (ch == '"') { |
| inString = !inString; |
| } else { |
| if (!inString) { |
| if (ch == '/') { |
| ch = in.read(); |
| if (ch == '/') { |
| while (ch != '\n' && ch != -1) { |
| ch = in.read(); |
| } |
| } else if (ch == '*') { |
| while (ch != -1) { |
| ch = in.read(); |
| if (ch == '*') { |
| ch = in.read(); |
| while (ch == '*' && ch != -1) { |
| ch = in.read(); |
| } |
| |
| if (ch == '/') { |
| ch = read(); |
| break; |
| } |
| } |
| } |
| } else { |
| readAheadCh = ch; |
| ch = '/'; |
| } |
| } |
| } |
| } |
| } |
| |
| return ch; |
| } |
| |
| /** |
| * Creates a new StripJavaComments using the passed in |
| * Reader for instantiation. |
| * |
| * @param rdr A Reader object providing the underlying stream. |
| * Must not be <code>null</code>. |
| * |
| * @return a new filter based on this configuration, but filtering |
| * the specified reader |
| */ |
| |
| public final Reader chain(final Reader rdr) { |
| StripJavaComments newFilter = new StripJavaComments(rdr); |
| return newFilter; |
| } |
| } |