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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.lookup;
    18
    19  import org.apache.logging.log4j.core.LogEvent;
    20  import org.apache.logging.log4j.core.config.plugins.Plugin;
    21  import org.apache.logging.log4j.message.StructuredDataMessage;
    22
    23  /**
    24   * Looks up keys from {@link org.apache.logging.log4j.message.StructuredDataMessage} log messages.
    25   */
    26  @Plugin(name = "sd", category = StrLookup.CATEGORY)
    27  public class StructuredDataLookup implements StrLookup {
    28
    29      /**
    30       * Returns {@code null}. This Lookup plugin does not make sense outside the context of a LogEvent.
    31       * @param key  the key to be looked up, may be null
    32       * @return {@code null}
    33       */
    34      @Override
    35      public String lookup(final String key) {
    36          return null;
    37      }
    38
    39      /**
    40       * Looks up the value for the key using the data in the LogEvent.
    41       * @param event The current LogEvent.
    42       * @param key  the key to be looked up, may be null
    43       * @return The value associated with the key.
    44       */
    45      @Override
    46      public String lookup(final LogEvent event, final String key) {
    47          if (event == null || !(event.getMessage() instanceof StructuredDataMessage)) {
    48              return null;
    49          }
    50          final StructuredDataMessage msg = (StructuredDataMessage) event.getMessage();
    51          if (key.equalsIgnoreCase("id")) {
    52              return msg.getId().getName();
    53          } else if (key.equalsIgnoreCase("type")) {
    54              return msg.getType();
    55          }
    56          return msg.get(key);
    57      }
    58  }