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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.log4j.spi;
18  
19  import java.util.Enumeration;
20  
21  import org.apache.log4j.Appender;
22  import org.apache.log4j.Category;
23  import org.apache.log4j.Level;
24  import org.apache.log4j.Logger;
25  
26  /**
27   * A <code>LoggerRepository</code> is used to create and retrieve <code>Loggers</code>.
28   * <p>
29   * The relation between loggers in a repository depends on the repository but typically loggers are arranged in a named
30   * hierarchy.
31   * </p>
32   * <p>
33   * In addition to the creational methods, a <code>LoggerRepository</code> can be queried for existing loggers, can act
34   * as a point of registry for events related to loggers.
35   * </p>
36   *
37   * @since 1.2
38   */
39  public interface LoggerRepository {
40  
41      /**
42       * Add a {@link HierarchyEventListener} event to the repository.
43       *
44       * @param listener The listener
45       */
46      void addHierarchyEventListener(HierarchyEventListener listener);
47  
48      /**
49       * Returns whether this repository is disabled for a given
50       * level. The answer depends on the repository threshold and the
51       * <code>level</code> parameter. See also {@link #setThreshold}
52       * method.
53       *
54       * @param level The level
55       * @return whether this repository is disabled.
56       */
57      boolean isDisabled(int level);
58  
59      /**
60       * Set the repository-wide threshold. All logging requests below the
61       * threshold are immediately dropped. By default, the threshold is
62       * set to <code>Level.ALL</code> which has the lowest possible rank.
63       *
64       * @param level The level
65       */
66      void setThreshold(Level level);
67  
68      /**
69       * Another form of {@link #setThreshold(Level)} accepting a string
70       * parameter instead of a <code>Level</code>.
71       *
72       * @param val The threshold value
73       */
74      void setThreshold(String val);
75  
76      void emitNoAppenderWarning(Category cat);
77  
78      /**
79       * Get the repository-wide threshold. See {@link #setThreshold(Level)} for an explanation.
80       *
81       * @return the level.
82       */
83      Level getThreshold();
84  
85      Logger getLogger(String name);
86  
87      Logger getLogger(String name, LoggerFactory factory);
88  
89      Logger getRootLogger();
90  
91      Logger exists(String name);
92  
93      void shutdown();
94  
95      @SuppressWarnings("rawtypes")
96      Enumeration getCurrentLoggers();
97  
98      /**
99       * Deprecated. Please use {@link #getCurrentLoggers} instead.
100      *
101      * @return an enumeration of loggers.
102      */
103     @SuppressWarnings("rawtypes")
104     Enumeration getCurrentCategories();
105 
106     void fireAddAppenderEvent(Category logger, Appender appender);
107 
108     void resetConfiguration();
109 }