001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2020 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.filters;
021
022import com.puppycrawl.tools.checkstyle.api.AuditEvent;
023import com.puppycrawl.tools.checkstyle.api.AutomaticBean;
024import com.puppycrawl.tools.checkstyle.api.Filter;
025import com.puppycrawl.tools.checkstyle.api.SeverityLevel;
026
027/**
028 * <p>
029 * Filter {@code SeverityMatchFilter} decides audit events according to the
030 * <a href="https://checkstyle.org/config.html#Severity">severity level</a> of the event.
031 * </p>
032 * <p>
033 * SeverityMatchFilter can suppress Checks that have Treewalker or Checker as parent module.
034 * </p>
035 * <ul>
036 * <li>
037 * Property {@code severity} - Specify the severity level of this filter.
038 * Type is {@code com.puppycrawl.tools.checkstyle.api.SeverityLevel}.
039 * Default value is {@code error}.
040 * </li>
041 * <li>
042 * Property {@code acceptOnMatch} - Control whether the filter accepts an audit
043 * event if and only if there is a match between the event's severity level and
044 * property severity. If acceptOnMatch is {@code false}, then the filter accepts
045 * an audit event if and only if there is not a match between the event's severity
046 * level and property severity.
047 * Type is {@code boolean}.
048 * Default value is {@code true}.
049 * </li>
050 * </ul>
051 * <p>
052 * For example, the following configuration fragment directs the Checker to not
053 * report audit events with severity level {@code info}:
054 * </p>
055 * <pre>
056 * &lt;module name=&quot;SeverityMatchFilter&quot;&gt;
057 *   &lt;property name=&quot;severity&quot; value=&quot;info&quot;/&gt;
058 *   &lt;property name=&quot;acceptOnMatch&quot; value=&quot;false&quot;/&gt;
059 * &lt;/module&gt;
060 * </pre>
061 * <p>
062 * Parent is {@code com.puppycrawl.tools.checkstyle.Checker}
063 * </p>
064 *
065 * @since 3.2
066 */
067public class SeverityMatchFilter
068    extends AutomaticBean
069    implements Filter {
070
071    /** Specify the severity level of this filter. */
072    private SeverityLevel severity = SeverityLevel.ERROR;
073
074    /**
075     * Control whether the filter accepts an audit event if and only if there
076     * is a match between the event's severity level and property severity.
077     * If acceptOnMatch is {@code false}, then the filter accepts an audit event
078     * if and only if there is not a match between the event's severity level
079     * and property severity.
080     */
081    private boolean acceptOnMatch = true;
082
083    /**
084     * Setter to specify the severity level of this filter.
085     *
086     * @param severity  The new severity level
087     * @see SeverityLevel
088     */
089    public final void setSeverity(SeverityLevel severity) {
090        this.severity = severity;
091    }
092
093    /**
094     * Setter to control whether the filter accepts an audit event if and only if there
095     * is a match between the event's severity level and property severity.
096     * If acceptOnMatch is {@code false}, then the filter accepts an audit event
097     * if and only if there is not a match between the event's severity level and property severity.
098     *
099     * @param acceptOnMatch if true, accept on matches; if
100     *     false, reject on matches.
101     */
102    public final void setAcceptOnMatch(boolean acceptOnMatch) {
103        this.acceptOnMatch = acceptOnMatch;
104    }
105
106    @Override
107    protected void finishLocalSetup() {
108        // No code by default
109    }
110
111    @Override
112    public boolean accept(AuditEvent event) {
113        final boolean severityMatches = severity == event.getSeverityLevel();
114        return acceptOnMatch == severityMatches;
115    }
116
117}