001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2017 the original author or authors.
004//
005// This library is free software; you can redistribute it and/or
006// modify it under the terms of the GNU Lesser General Public
007// License as published by the Free Software Foundation; either
008// version 2.1 of the License, or (at your option) any later version.
009//
010// This library is distributed in the hope that it will be useful,
011// but WITHOUT ANY WARRANTY; without even the implied warranty of
012// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013// Lesser General Public License for more details.
014//
015// You should have received a copy of the GNU Lesser General Public
016// License along with this library; if not, write to the Free Software
017// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
018////////////////////////////////////////////////////////////////////////////////
019
020package com.puppycrawl.tools.checkstyle.filefilters;
021
022import java.util.regex.Pattern;
023
024import com.puppycrawl.tools.checkstyle.api.AutomaticBean;
025import com.puppycrawl.tools.checkstyle.api.BeforeExecutionFileFilter;
026
027/**
028 * <p>
029 * File filter {@code BeforeExecutionExclusionFileFilter} decides which files should be
030 * excluded from being processed by the utility.
031 * </p>
032 *
033 * <p>
034 * By default Checkstyle includes all files and sub-directories in a directory to be processed and
035 * checked for violations. Users could have files that are in these sub-directories that shouldn't
036 * be processed with their checkstyle configuration for various reasons, one of which is a valid
037 * Java file that won't pass Checkstyle's parser. When Checkstyle tries to parse a Java file and
038 * fails, it will throw an {@code Exception} and halt parsing any more files for violations.
039 * An example of a valid Java file Checkstyle can't parse is JDK 9's {@code module-info.java}.
040 * This file filter will exclude these problem files from being parsed, allowing the rest of the
041 * files to run normal and be validated.
042 * </p>
043 *
044 * <p>
045 * <b>Note:</b> When a file is excluded from the utility, it is excluded from all Checks and no
046 * testing for violations will be performed on them.
047 * </p>
048 *
049 * <p>
050 * Check have following options:
051 * </p>
052 * <ul>
053 * <li>
054 * fileNamePattern - Regular expression to match the file name against. Default value is null.</li>
055 * </ul>
056 * <br>
057 *
058 * <p>
059 * To configure the filter to exclude all 'module-info.java' files:
060 * </p>
061 *
062 * <pre>
063 * &lt;module name=&quot;BeforeExecutionExclusionFileFilter&quot;&gt;
064 *   &lt;property name=&quot;fileNamePattern&quot; value=&quot;module\-info\.java$&quot;/&gt;
065 * &lt;/module&gt;
066 * </pre>
067 *
068 * @author Richard Veach
069 */
070public final class BeforeExecutionExclusionFileFilter extends AutomaticBean
071        implements BeforeExecutionFileFilter {
072
073    /** Filename of exclusion. */
074    private Pattern fileNamePattern;
075
076    /**
077     * Sets regular expression of the file to exclude.
078     *
079     * @param fileNamePattern regular expression of the excluded file.
080     */
081    public void setFileNamePattern(Pattern fileNamePattern) {
082        this.fileNamePattern = fileNamePattern;
083    }
084
085    @Override
086    public boolean accept(String uri) {
087        return fileNamePattern == null || !fileNamePattern.matcher(uri).find();
088    }
089}