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 */
017package org.apache.logging.log4j.core.filter;
018
019import java.lang.reflect.Field;
020import java.util.Arrays;
021import java.util.Comparator;
022import java.util.regex.Matcher;
023import java.util.regex.Pattern;
024
025import org.apache.logging.log4j.Level;
026import org.apache.logging.log4j.Marker;
027import org.apache.logging.log4j.core.LogEvent;
028import org.apache.logging.log4j.core.Logger;
029import org.apache.logging.log4j.core.config.plugins.Plugin;
030import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
031import org.apache.logging.log4j.core.config.plugins.PluginElement;
032import org.apache.logging.log4j.core.config.plugins.PluginFactory;
033import 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)
043public 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}