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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.pattern;
    18
    19  import org.apache.logging.log4j.core.LogEvent;
    20  import org.apache.logging.log4j.core.config.Configuration;
    21  import org.apache.logging.log4j.core.config.plugins.Plugin;
    22  import org.apache.logging.log4j.message.Message;
    23  import org.apache.logging.log4j.message.MultiformatMessage;
    24
    25  /**
    26   * Returns the event's rendered message in a StringBuilder.
    27   */
    28  @Plugin(name = "MessagePatternConverter", category = PatternConverter.CATEGORY)
    29  @ConverterKeys({ "m", "msg", "message" })
    30  public final class MessagePatternConverter extends LogEventPatternConverter {
    31
    32      private final String[] formats;
    33
    34      private final Configuration config;
    35
    36      /**
    37       * Private constructor.
    38       * @param options options, may be null.
    39       */
    40      private MessagePatternConverter(final Configuration config, final String[] options) {
    41          super("Message", "message");
    42          formats = options;
    43          this.config = config;
    44      }
    45
    46      /**
    47       * Obtains an instance of pattern converter.
    48       *
    49       * @param config The Configuration.
    50       * @param options options, may be null.
    51       * @return instance of pattern converter.
    52       */
    53      public static MessagePatternConverter newInstance(final Configuration config, final String[] options) {
    54          return new MessagePatternConverter(config, options);
    55      }
    56
    57      /**
    58       * {@inheritDoc}
    59       */
    60      @Override
    61      public void format(final LogEvent event, final StringBuilder toAppendTo) {
    62          final Message msg = event.getMessage();
    63          if (msg != null) {
    64              String result;
    65              if (msg instanceof MultiformatMessage) {
    66                  result = ((MultiformatMessage) msg).getFormattedMessage(formats);
    67              } else {
    68                  result = msg.getFormattedMessage();
    69              }
    70              if (result != null) {
    71                  toAppendTo.append(config != null && result.contains("${") ?
    72                      config.getStrSubstitutor().replace(event, result) : result);
    73              } else {
    74                  toAppendTo.append("null");
    75              }
    76          }
    77      }
    78  }