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    1   /*
    2    * Licensed to the Apache Software Foundation (ASF) under one or more
    3    * contributor license agreements. See the NOTICE file distributed with
    4    * this work for additional information regarding copyright ownership.
    5    * The ASF licenses this file to You under the Apache license, Version 2.0
    6    * (the "License"); you may not use this file except in compliance with
    7    * the License. You may obtain a copy of the License at
    8    *
    9    *      http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the license for the specific language governing permissions and
    15   * limitations under the license.
    16   */
    17  package org.apache.logging.log4j.core.filter;
    18
    19  import java.lang.reflect.Field;
    20  import java.util.Arrays;
    21  import java.util.Comparator;
    22  import java.util.regex.Matcher;
    23  import java.util.regex.Pattern;
    24
    25  import org.apache.logging.log4j.Level;
    26  import org.apache.logging.log4j.Marker;
    27  import org.apache.logging.log4j.core.Filter;
    28  import org.apache.logging.log4j.core.LogEvent;
    29  import org.apache.logging.log4j.core.Logger;
    30  import org.apache.logging.log4j.core.config.Node;
    31  import org.apache.logging.log4j.core.config.plugins.Plugin;
    32  import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
    33  import org.apache.logging.log4j.core.config.plugins.PluginElement;
    34  import org.apache.logging.log4j.core.config.plugins.PluginFactory;
    35  import org.apache.logging.log4j.message.Message;
    36
    37  /**
    38   * This filter returns the onMatch result if the message matches the regular expression.
    39   *
    40   * The "useRawMsg" attribute can be used to indicate whether the regular expression should be applied to the result of
    41   * calling Message.getMessageFormat (true) or Message.getFormattedMessage() (false). The default is false.
    42   *
    43   */
    44  @Plugin(name = "RegexFilter", category = Node.CATEGORY, elementType = Filter.ELEMENT_TYPE, printObject = true)
    45  public final class RegexFilter extends AbstractFilter {
    46
    47      private static final long serialVersionUID = 1L;
    48
    49      private static final int DEFAULT_PATTERN_FLAGS = 0;
    50      private final Pattern pattern;
    51      private final boolean useRawMessage;
    52
    53      private RegexFilter(final boolean raw, final Pattern pattern, final Result onMatch, final Result onMismatch) {
    54          super(onMatch, onMismatch);
    55          this.pattern = pattern;
    56          this.useRawMessage = raw;
    57      }
    58
    59      @Override
    60      public Result filter(final Logger logger, final Level level, final Marker marker, final String msg,
    61              final Object... params) {
    62          return filter(msg);
    63      }
    64
    65      @Override
    66      public Result filter(final Logger logger, final Level level, final Marker marker, final Object msg,
    67              final Throwable t) {
    68          if (msg == null) {
    69              return onMismatch;
    70          }
    71          return filter(msg.toString());
    72      }
    73
    74      @Override
    75      public Result filter(final Logger logger, final Level level, final Marker marker, final Message msg,
    76              final Throwable t) {
    77          if (msg == null) {
    78              return onMismatch;
    79          }
    80          final String text = useRawMessage ? msg.getFormat() : msg.getFormattedMessage();
    81          return filter(text);
    82      }
    83
    84      @Override
    85      public Result filter(final LogEvent event) {
    86          final String text = useRawMessage ? event.getMessage().getFormat() : event.getMessage().getFormattedMessage();
    87          return filter(text);
    88      }
    89
    90      private Result filter(final String msg) {
    91          if (msg == null) {
    92              return onMismatch;
    93          }
    94          final Matcher m = pattern.matcher(msg);
    95          return m.matches() ? onMatch : onMismatch;
    96      }
    97
    98      @Override
    99      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 }