1 package org.eclipse.aether.spi.log;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 /**
23 * A logger factory that disables any logging.
24 */
25 public final class NullLoggerFactory
26 implements LoggerFactory
27 {
28
29 /**
30 * The singleton instance of this factory.
31 */
32 public static final LoggerFactory INSTANCE = new NullLoggerFactory();
33
34 /**
35 * The singleton logger used by this factory.
36 */
37 public static final Logger LOGGER = new NullLogger();
38
39 public Logger getLogger( String name )
40 {
41 return LOGGER;
42 }
43
44 private NullLoggerFactory()
45 {
46 // hide constructor
47 }
48
49 /**
50 * Gets a logger from the specified factory for the given class, falling back to a logger from this factory if the
51 * specified factory is {@code null} or fails to provide a logger.
52 *
53 * @param loggerFactory The logger factory from which to get the logger, may be {@code null}.
54 * @param type The class for which to get the logger, must not be {@code null}.
55 * @return The requested logger, never {@code null}.
56 */
57 public static Logger getSafeLogger( LoggerFactory loggerFactory, Class<?> type )
58 {
59 if ( loggerFactory == null )
60 {
61 return LOGGER;
62 }
63 Logger logger = loggerFactory.getLogger( type.getName() );
64 if ( logger == null )
65 {
66 return LOGGER;
67 }
68 return logger;
69 }
70
71 }