View Javadoc
1   /*
2    * #%L
3    * Slf4jLog.java - mongodb-async-driver - Allanbank Consulting, Inc.
4    * %%
5    * Copyright (C) 2011 - 2014 Allanbank Consulting, Inc.
6    * %%
7    * Licensed under the Apache License, Version 2.0 (the "License");
8    * you may not use this file except in compliance with the License.
9    * You may obtain a copy of the License at
10   * 
11   *      http://www.apache.org/licenses/LICENSE-2.0
12   * 
13   * Unless required by applicable law or agreed to in writing, software
14   * distributed under the License is distributed on an "AS IS" BASIS,
15   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16   * See the License for the specific language governing permissions and
17   * limitations under the License.
18   * #L%
19   */
20  package com.allanbank.mongodb.util.log;
21  
22  import java.lang.reflect.InvocationTargetException;
23  import java.lang.reflect.Method;
24  import java.util.logging.Level;
25  import java.util.logging.LogRecord;
26  import java.util.logging.Logger;
27  
28  /**
29   * Slf4jLog is the simplified logging implementation for SLF4J logging facade.
30   * 
31   * @api.no This class is <b>NOT</b> part of the drivers API. This class may be
32   *         mutated in incompatible ways between any two releases of the driver.
33   * @copyright 2014, Allanbank Consulting, Inc., All Rights Reserved
34   */
35  public class Slf4jLog extends AbstractLog {
36  
37      /** The delegate for the log to a SLF4J <code>LocationAwareLogger</code>. */
38      private final Object myDelegate;
39  
40      /**
41       * The <code>log(Marker, String, int, String, Object[])</code> method from
42       * the <code>LocationAwareLogger</code> interface.
43       */
44      private final Method myLogMethod;
45  
46      /**
47       * Creates a new {@link Slf4jLog}.
48       * 
49       * @param logMethod
50       *            The <code>log(Marker, String, int, String, Object[])</code>
51       *            method from the <code>LocationAwareLogger</code> interface.
52       * @param logger
53       *            The SLF4J Logger.
54       */
55      protected Slf4jLog(final Method logMethod, final Object logger) {
56          myDelegate = logger;
57          myLogMethod = logMethod;
58      }
59  
60      /**
61       * {@inheritDoc}
62       * <p>
63       * Overridden to create a {@link LogRecord} based on the log information.
64       * </p>
65       * 
66       * @see AbstractLog#doLog(Level, Throwable, String, Object...)
67       */
68      @Override
69      protected final void doLog(final Level level, final Throwable thrown,
70              final String template, final Object... args) {
71          // Note the name of the class is the AbstractLog which is where all of
72          // the public log methods are implemented.
73          try {
74              myLogMethod.invoke(myDelegate, new Object[] { null, CLASS_NAME,
75                      toInt(level), template, args, thrown });
76          }
77          catch (final IllegalArgumentException e) {
78              Logger.getLogger(Slf4jLog.class.getName()).log(Level.WARNING,
79                      "Failed to log a message: " + e.getMessage(), e);
80          }
81          catch (final IllegalAccessException e) {
82              Logger.getLogger(Slf4jLog.class.getName()).log(Level.WARNING,
83                      "Failed to log a message: " + e.getMessage(), e);
84          }
85          catch (final InvocationTargetException e) {
86              Logger.getLogger(Slf4jLog.class.getName()).log(Level.WARNING,
87                      "Failed to log a message: " + e.getMessage(), e);
88          }
89      }
90  
91      /**
92       * Returns the integer level for the {@link Level} as defined in the
93       * LocationAwareLogger interface.
94       * 
95       * @param level
96       *            The level to convert.
97       * @return The integer level.
98       */
99      private Integer toInt(final Level level) {
100         final int levelIntValue = (level != null) ? level.intValue() : 0;
101 
102         // Note: Return values are from the <code>LocationAwareLogger</code>
103         // interface.
104         if (levelIntValue == 0) {
105             return 0;
106         }
107         else if (levelIntValue <= Level.FINE.intValue()) {
108             return 10;
109         }
110         else if (levelIntValue <= Level.INFO.intValue()) {
111             return 20;
112         }
113         else if (levelIntValue <= Level.WARNING.intValue()) {
114             return 30;
115         }
116         else {
117             return 40;
118         }
119     }
120 }