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    }