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1   /**
2    * Logback: the reliable, generic, fast and flexible logging framework.
3    * Copyright (C) 1999-2009, QOS.ch. All rights reserved.
4    *
5    * This program and the accompanying materials are dual-licensed under
6    * either the terms of the Eclipse Public License v1.0 as published by
7    * the Eclipse Foundation
8    *
9    *   or (per the licensee's choosing)
10   *
11   * under the terms of the GNU Lesser General Public License version 2.1
12   * as published by the Free Software Foundation.
13   */
14  package ch.qos.logback.core.boolex;
15  
16  import ch.qos.logback.core.spi.ContextAware;
17  import ch.qos.logback.core.spi.LifeCycle;
18  
19  /**
20   * Evaluates whether a given an event matches user-specified criteria.
21   * 
22   * <p>
23   * Implementations are free to evaluate the event as they see fit. In
24   * particular, the evaluation results <em>may</em> depend on previous events.
25   * 
26   * @author Ceki G&uuml;lc&uuml;
27   */
28  
29  public interface EventEvaluator<E> extends ContextAware, LifeCycle {
30  
31    /**
32     * Evaluates whether the event passed as parameter matches some user-specified
33     * criteria.
34     * 
35     * <p>
36     * The <code>Evaluator</code> is free to evaluate the event as it pleases. In
37     * particular, the evaluation results <em>may</em> depend on previous events.
38     * 
39     * @param event
40     *          The event to evaluate
41     * @return true if there is a match, false otherwise.
42     * @throws NullPointerException
43     *           can be thrown in presence of null values
44     * @throws EvaluationException
45     *           may be thrown during faulty evaluation
46     */
47    boolean evaluate(E event) throws NullPointerException, EvaluationException;
48  
49    /**
50     * Evaluators are named entities.
51     * 
52     * @return The name of this evaluator.
53     */
54    public String getName();
55  
56    /**
57     * Evaluators are named entities.
58     */
59    public void setName(String name);
60  }