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