| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| */ |
| package org.apache.tools.ant.filters; |
| |
| import java.io.IOException; |
| import java.io.Reader; |
| import java.util.Vector; |
| import org.apache.tools.ant.types.Parameter; |
| |
| /** |
| * This filter strips line comments. |
| * |
| * Example: |
| * |
| * <pre><striplinecomments> |
| * <comment value="#"/> |
| * <comment value="--"/> |
| * <comment value="REM "/> |
| * <comment value="rem "/> |
| * <comment value="//"/> |
| * </striplinecomments></pre> |
| * |
| * Or: |
| * |
| * <pre><filterreader |
| * classname="org.apache.tools.ant.filters.StripLineComments"> |
| * <param type="comment" value="#"/> |
| * <param type="comment" value="--"/> |
| * <param type="comment" value="REM "/> |
| * <param type="comment" value="rem "/> |
| * <param type="comment" value="//"/> |
| * </filterreader></pre> |
| * |
| */ |
| public final class StripLineComments |
| extends BaseParamFilterReader |
| implements ChainableReader { |
| /** Parameter name for the comment prefix. */ |
| private static final String COMMENTS_KEY = "comment"; |
| |
| /** Vector that holds the comment prefixes. */ |
| private Vector comments = new Vector(); |
| |
| /** The line that has been read ahead. */ |
| private String line = null; |
| |
| /** |
| * Constructor for "dummy" instances. |
| * |
| * @see BaseFilterReader#BaseFilterReader() |
| */ |
| public StripLineComments() { |
| super(); |
| } |
| |
| /** |
| * Creates a new filtered reader. |
| * |
| * @param in A Reader object providing the underlying stream. |
| * Must not be <code>null</code>. |
| */ |
| public StripLineComments(final Reader in) { |
| super(in); |
| } |
| |
| /** |
| * Returns the next character in the filtered stream, only including |
| * lines from the original stream which don't start with any of the |
| * specified comment prefixes. |
| * |
| * @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 int read() throws IOException { |
| if (!getInitialized()) { |
| initialize(); |
| setInitialized(true); |
| } |
| |
| int ch = -1; |
| |
| if (line != null) { |
| ch = line.charAt(0); |
| if (line.length() == 1) { |
| line = null; |
| } else { |
| line = line.substring(1); |
| } |
| } else { |
| line = readLine(); |
| final int commentsSize = comments.size(); |
| |
| while (line != null) { |
| for (int i = 0; i < commentsSize; i++) { |
| String comment = (String) comments.elementAt(i); |
| if (line.startsWith(comment)) { |
| line = null; |
| break; |
| } |
| } |
| |
| if (line == null) { |
| // line started with comment |
| line = readLine(); |
| } else { |
| break; |
| } |
| } |
| |
| if (line != null) { |
| return read(); |
| } |
| } |
| |
| return ch; |
| } |
| |
| /** |
| * Adds a <code>comment</code> element to the list of prefixes. |
| * |
| * @param comment The <code>comment</code> element to add to the |
| * list of comment prefixes to strip. Must not be <code>null</code>. |
| */ |
| public void addConfiguredComment(final Comment comment) { |
| comments.addElement(comment.getValue()); |
| } |
| |
| /** |
| * Sets the list of comment prefixes to strip. |
| * |
| * @param comments A list of strings, each of which is a prefix |
| * for a comment line. Must not be <code>null</code>. |
| */ |
| private void setComments(final Vector comments) { |
| this.comments = comments; |
| } |
| |
| /** |
| * Returns the list of comment prefixes to strip. |
| * |
| * @return the list of comment prefixes to strip. |
| */ |
| private Vector getComments() { |
| return comments; |
| } |
| |
| /** |
| * Creates a new StripLineComments 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 Reader chain(final Reader rdr) { |
| StripLineComments newFilter = new StripLineComments(rdr); |
| newFilter.setComments(getComments()); |
| newFilter.setInitialized(true); |
| return newFilter; |
| } |
| |
| /** |
| * Parses the parameters to set the comment prefixes. |
| */ |
| private void initialize() { |
| Parameter[] params = getParameters(); |
| if (params != null) { |
| for (int i = 0; i < params.length; i++) { |
| if (COMMENTS_KEY.equals(params[i].getType())) { |
| comments.addElement(params[i].getValue()); |
| } |
| } |
| } |
| } |
| |
| /** |
| * The class that holds a comment representation. |
| */ |
| public static class Comment { |
| |
| /** The prefix for a line comment. */ |
| private String value; |
| |
| /** |
| * Sets the prefix for this type of line comment. |
| * |
| * @param comment The prefix for a line comment of this type. |
| * Must not be <code>null</code>. |
| */ |
| public final void setValue(String comment) { |
| if (value != null) { |
| throw new IllegalStateException("Comment value already set."); |
| } |
| value = comment; |
| } |
| |
| /** |
| * Returns the prefix for this type of line comment. |
| * |
| * @return the prefix for this type of line comment. |
| */ |
| public final String getValue() { |
| return value; |
| } |
| |
| /** |
| * Alt. syntax to set the prefix for this type of line comment. |
| * |
| * @param comment The prefix for a line comment of this type. |
| * Must not be <code>null</code>. |
| */ |
| public void addText(String comment) { |
| setValue(comment); |
| } |
| } |
| } |