1   /**
2    * Logback: the reliable, generic, fast and flexible logging framework.
3    * Copyright (C) 1999-2015, 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.classic.turbo;
15  
16  import org.slf4j.MDC;
17  import org.slf4j.Marker;
18  
19  import ch.qos.logback.classic.Level;
20  import ch.qos.logback.classic.Logger;
21  import ch.qos.logback.core.spi.FilterReply;
22  
23  /**
24   * This class allows output for a given MDC value.
25   * 
26   * <p>
27   * When the given value is identified by this TurboFilter, the reply is based on
28   * the OnMatch option. The information is taken from the MDC. For this
29   * TurboFilter to work, one must set the key that will be used to access the
30   * information in the MDC.
31   * 
32   * <p>
33   * To allow output for the value, set the OnMatch option to ACCEPT. To disable
34   * output for the given value, set the OnMatch option to DENY.
35   * 
36   * <p>
37   * By default, values of the OnMatch and OnMisMatch options are set to NEUTRAL.
38   * 
39   *
40   * @author Ceki G&uuml;lc&uuml;
41   * @author S&eacute;bastien Pennec
42   */
43  public class MDCFilter extends MatchingFilter {
44  
45      String MDCKey;
46      String value;
47  
48      @Override
49      public void start() {
50          int errorCount = 0;
51          if (value == null) {
52              addError("\'value\' parameter is mandatory. Cannot start.");
53              errorCount++;
54          }
55          if (MDCKey == null) {
56              addError("\'MDCKey\' parameter is mandatory. Cannot start.");
57              errorCount++;
58          }
59  
60          if (errorCount == 0)
61              this.start = true;
62      }
63  
64      @Override
65      public FilterReply decide(Marker marker, Logger logger, Level level, String format, Object[] params, Throwable t) {
66  
67          if (!isStarted()) {
68              return FilterReply.NEUTRAL;
69          }
70  
71          String value = MDC.get(MDCKey);
72          if (this.value.equals(value)) {
73              return onMatch;
74          }
75          return onMismatch;
76      }
77  
78      public void setValue(String value) {
79          this.value = value;
80      }
81  
82      public void setMDCKey(String MDCKey) {
83          this.MDCKey = MDCKey;
84      }
85  
86  }