View Javadoc

    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.spi;
    18
    19  import java.util.Map;
    20
    21  /**
    22   * Service provider interface to implement custom MDC behavior for {@link org.apache.logging.log4j.ThreadContext}.
    23   */
    24  public interface ThreadContextMap {
    25      /**
    26       * Put a context value (the <code>o</code> parameter) as identified
    27       * with the <code>key</code> parameter into the current thread's
    28       * context map.
    29       *
    30       * <p>If the current thread does not have a context map it is
    31       * created as a side effect.</p>
    32       * @param key The key name.
    33       * @param value The key value.
    34       */
    35      void put(final String key, final String value);
    36
    37      /**
    38       * Get the context identified by the <code>key</code> parameter.
    39       *
    40       * <p>This method has no side effects.</p>
    41       * @param key The key to locate.
    42       * @return The value associated with the key or null.
    43       */
    44      String get(final String key);
    45
    46      /**
    47       * Remove the the context identified by the <code>key</code>
    48       * parameter.
    49       * @param key The key to remove.
    50       */
    51      void remove(final String key);
    52
    53      /**
    54       * Clear the context.
    55       */
    56      void clear();
    57
    58      /**
    59       * Determine if the key is in the context.
    60       * @param key The key to locate.
    61       * @return True if the key is in the context, false otherwise.
    62       */
    63      boolean containsKey(final String key);
    64
    65      /**
    66       * Get a non-{@code null} mutable copy of current thread's context Map.
    67       * @return a mutable copy of the context.
    68       */
    69      Map<String, String> getCopy();
    70
    71      /**
    72       * Return an immutable view on the context Map or {@code null} if the context map is empty.
    73       * @return an immutable context Map or {@code null}.
    74       */
    75      Map<String, String> getImmutableMapOrNull();
    76
    77      /**
    78       * Returns true if the Map is empty.
    79       * @return true if the Map is empty, false otherwise.
    80       */
    81      boolean isEmpty();
    82  }