    001    /*
    002     * Licensed to the Apache Software Foundation (ASF) under one or more
    003     * contributor license agreements. See the NOTICE file distributed with
    004     * this work for additional information regarding copyright ownership.
    005     * The ASF licenses this file to You under the Apache license, Version 2.0
    006     * (the "License"); you may not use this file except in compliance with
    007     * the License. You may obtain a copy of the License at
    008     *
    009     *      http://www.apache.org/licenses/LICENSE-2.0
    010     *
    011     * Unless required by applicable law or agreed to in writing, software
    012     * distributed under the License is distributed on an "AS IS" BASIS,
    013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014     * See the license for the specific language governing permissions and
    015     * limitations under the license.
    016     */
    017    package org.apache.logging.log4j.core.filter;
    018
    019    import java.lang.reflect.Field;
    020    import java.util.Arrays;
    021    import java.util.Comparator;
    022    import java.util.regex.Matcher;
    023    import java.util.regex.Pattern;
    024
    025    import org.apache.logging.log4j.Level;
    026    import org.apache.logging.log4j.Marker;
    027    import org.apache.logging.log4j.core.Filter;
    028    import org.apache.logging.log4j.core.LogEvent;
    029    import org.apache.logging.log4j.core.Logger;
    030    import org.apache.logging.log4j.core.config.Node;
    031    import org.apache.logging.log4j.core.config.plugins.Plugin;
    032    import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
    033    import org.apache.logging.log4j.core.config.plugins.PluginElement;
    034    import org.apache.logging.log4j.core.config.plugins.PluginFactory;
    035    import org.apache.logging.log4j.message.Message;
    036
    037    /**
    038     * This filter returns the onMatch result if the message matches the regular expression.
    039     *
    040     * The "useRawMsg" attribute can be used to indicate whether the regular expression should be applied to the result of
    041     * calling Message.getMessageFormat (true) or Message.getFormattedMessage() (false). The default is false.
    042     *
    043     */
    044    @Plugin(name = "RegexFilter", category = Node.CATEGORY, elementType = Filter.ELEMENT_TYPE, printObject = true)
    045    public final class RegexFilter extends AbstractFilter {
    046
    047        private static final long serialVersionUID = 1L;
    048
    049        private static final int DEFAULT_PATTERN_FLAGS = 0;
    050        private final Pattern pattern;
    051        private final boolean useRawMessage;
    052
    053        private RegexFilter(final boolean raw, final Pattern pattern, final Result onMatch, final Result onMismatch) {
    054            super(onMatch, onMismatch);
    055            this.pattern = pattern;
    056            this.useRawMessage = raw;
    057        }
    058
    059        @Override
    060        public Result filter(final Logger logger, final Level level, final Marker marker, final String msg,
    061                final Object... params) {
    062            return filter(msg);
    063        }
    064
    065        @Override
    066        public Result filter(final Logger logger, final Level level, final Marker marker, final Object msg,
    067                final Throwable t) {
    068            if (msg == null) {
    069                return onMismatch;
    070            }
    071            return filter(msg.toString());
    072        }
    073
    074        @Override
    075        public Result filter(final Logger logger, final Level level, final Marker marker, final Message msg,
    076                final Throwable t) {
    077            if (msg == null) {
    078                return onMismatch;
    079            }
    080            final String text = useRawMessage ? msg.getFormat() : msg.getFormattedMessage();
    081            return filter(text);
    082        }
    083
    084        @Override
    085        public Result filter(final LogEvent event) {
    086            final String text = useRawMessage ? event.getMessage().getFormat() : event.getMessage().getFormattedMessage();
    087            return filter(text);
    088        }
    089
    090        private Result filter(final String msg) {
    091            if (msg == null) {
    092                return onMismatch;
    093            }
    094            final Matcher m = pattern.matcher(msg);
    095            return m.matches() ? onMatch : onMismatch;
    096        }
    097
    098        @Override
    099        public String toString() {
    100            final StringBuilder sb = new StringBuilder();
    101            sb.append("useRaw=").append(useRawMessage);
    102            sb.append(", pattern=").append(pattern.toString());
    103            return sb.toString();
    104        }
    105
    106        /**
    107         * Create a Filter that matches a regular expression.
    108         *
    109         * @param regex
    110         *        The regular expression to match.
    111         * @param patternFlags
    112         *        An array of Stirngs where each String is a {@link Pattern#compile(String, int)} compilation flag.
    113         * @param useRawMsg
    114         *        If true, the raw message will be used, otherwise the formatted message will be used.
    115         * @param match
    116         *        The action to perform when a match occurs.
    117         * @param mismatch
    118         *        The action to perform when a mismatch occurs.
    119         * @return The RegexFilter.
    120         * @throws IllegalAccessException
    121         * @throws IllegalArgumentException
    122         */
    123        @PluginFactory
    124        public static RegexFilter createFilter(
    125                //@formatter:off
    126                @PluginAttribute("regex") final String regex,
    127                @PluginElement("PatternFlags") final String[] patternFlags,
    128                @PluginAttribute("useRawMsg") final Boolean useRawMsg,
    129                @PluginAttribute("onMatch") final Result match,
    130                @PluginAttribute("onMismatch") final Result mismatch)
    131                //@formatter:on
    132                throws IllegalArgumentException, IllegalAccessException {
    133            if (regex == null) {
    134                LOGGER.error("A regular expression must be provided for RegexFilter");
    135                return null;
    136            }
    137            return new RegexFilter(useRawMsg, Pattern.compile(regex, toPatternFlags(patternFlags)), match, mismatch);
    138        }
    139
    140        private static int toPatternFlags(final String[] patternFlags) throws IllegalArgumentException,
    141                IllegalAccessException {
    142            if (patternFlags == null || patternFlags.length == 0) {
    143                return DEFAULT_PATTERN_FLAGS;
    144            }
    145            final Field[] fields = Pattern.class.getDeclaredFields();
    146            final Comparator<Field> comparator = new Comparator<Field>() {
    147
    148                @Override
    149                public int compare(final Field f1, final Field f2) {
    150                    return f1.getName().compareTo(f2.getName());
    151                }
    152            };
    153            Arrays.sort(fields, comparator);
    154            final String[] fieldNames = new String[fields.length];
    155            for (int i = 0; i < fields.length; i++) {
    156                fieldNames[i] = fields[i].getName();
    157            }
    158            int flags = DEFAULT_PATTERN_FLAGS;
    159            for (final String test : patternFlags) {
    160                final int index = Arrays.binarySearch(fieldNames, test);
    161                if (index >= 0) {
    162                    final Field field = fields[index];
    163                    flags |= field.getInt(Pattern.class);
    164                }
    165            }
    166            return flags;
    167        }
    168    }