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.LogEvent;
028    import org.apache.logging.log4j.core.Logger;
029    import org.apache.logging.log4j.core.config.plugins.Plugin;
030    import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
031    import org.apache.logging.log4j.core.config.plugins.PluginElement;
032    import org.apache.logging.log4j.core.config.plugins.PluginFactory;
033    import org.apache.logging.log4j.message.Message;
034    
035    /**
036     * This filter returns the onMatch result if the message matches the regular expression.
037     *
038     * The "useRawMsg" attribute can be used to indicate whether the regular expression should be applied to the result of
039     * calling Message.getMessageFormat (true) or Message.getFormattedMessage() (false). The default is false.
040     *
041     */
042    @Plugin(name = "RegexFilter", category = "Core", elementType = "filter", printObject = true)
043    public final class RegexFilter extends AbstractFilter {
044    
045        private static final int DEFAULT_PATTERN_FLAGS = 0;
046        private final Pattern pattern;
047        private final boolean useRawMessage;
048    
049        private RegexFilter(final boolean raw, final Pattern pattern, final Result onMatch, final Result onMismatch) {
050            super(onMatch, onMismatch);
051            this.pattern = pattern;
052            this.useRawMessage = raw;
053        }
054    
055        @Override
056        public Result filter(final Logger logger, final Level level, final Marker marker, final String msg,
057                final Object... params) {
058            return filter(msg);
059        }
060    
061        @Override
062        public Result filter(final Logger logger, final Level level, final Marker marker, final Object msg,
063                final Throwable t) {
064            if (msg == null) {
065                return onMismatch;
066            }
067            return filter(msg.toString());
068        }
069    
070        @Override
071        public Result filter(final Logger logger, final Level level, final Marker marker, final Message msg,
072                final Throwable t) {
073            if (msg == null) {
074                return onMismatch;
075            }
076            final String text = useRawMessage ? msg.getFormat() : msg.getFormattedMessage();
077            return filter(text);
078        }
079    
080        @Override
081        public Result filter(final LogEvent event) {
082            final String text = useRawMessage ? event.getMessage().getFormat() : event.getMessage().getFormattedMessage();
083            return filter(text);
084        }
085    
086        private Result filter(final String msg) {
087            if (msg == null) {
088                return onMismatch;
089            }
090            final Matcher m = pattern.matcher(msg);
091            return m.matches() ? onMatch : onMismatch;
092        }
093    
094        @Override
095        public String toString() {
096            final StringBuilder sb = new StringBuilder();
097            sb.append("useRaw=").append(useRawMessage);
098            sb.append(", pattern=").append(pattern.toString());
099            return sb.toString();
100        }
101    
102        /**
103         * Create a Filter that matches a regular expression.
104         * 
105         * @param regex
106         *        The regular expression to match.
107         * @param patternFlags
108         *        An array of Stirngs where each String is a {@link Pattern#compile(String, int)} compilation flag.
109         * @param useRawMsg
110         *        If true, the raw message will be used, otherwise the formatted message will be used.
111         * @param match
112         *        The action to perform when a match occurs.
113         * @param mismatch
114         *        The action to perform when a mismatch occurs.
115         * @return The RegexFilter.
116         * @throws IllegalAccessException
117         * @throws IllegalArgumentException
118         */
119        @PluginFactory
120        public static RegexFilter createFilter(
121                //@formatter:off
122                @PluginAttribute("regex") final String regex,
123                @PluginElement("PatternFlags") final String[] patternFlags,
124                @PluginAttribute("useRawMsg") final Boolean useRawMsg,
125                @PluginAttribute("onMatch") final Result match, 
126                @PluginAttribute("onMismatch") final Result mismatch) 
127                //@formatter:on
128                throws IllegalArgumentException, IllegalAccessException {
129            if (regex == null) {
130                LOGGER.error("A regular expression must be provided for RegexFilter");
131                return null;
132            }
133            return new RegexFilter(useRawMsg, Pattern.compile(regex, toPatternFlags(patternFlags)), match, mismatch);
134        }
135    
136        private static int toPatternFlags(final String[] patternFlags) throws IllegalArgumentException,
137                IllegalAccessException {
138            if (patternFlags == null || patternFlags.length == 0) {
139                return DEFAULT_PATTERN_FLAGS;
140            }
141            final Field[] fields = Pattern.class.getDeclaredFields();
142            final Comparator<Field> comparator = new Comparator<Field>() {
143    
144                @Override
145                public int compare(final Field f1, final Field f2) {
146                    return f1.getName().compareTo(f2.getName());
147                }
148            };
149            Arrays.sort(fields, comparator);
150            final String[] fieldNames = new String[fields.length];
151            for (int i = 0; i < fields.length; i++) {
152                fieldNames[i] = fields[i].getName();
153            }
154            int flags = DEFAULT_PATTERN_FLAGS;
155            for (final String test : patternFlags) {
156                final int index = Arrays.binarySearch(fieldNames, test);
157                if (index >= 0) {
158                    final Field field = fields[index];
159                    flags |= field.getInt(Pattern.class);
160                }
161            }
162            return flags;
163        }
164    }