View Javadoc
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.logging.slf4j;
18  
19  import java.net.URI;
20  
21  import org.apache.logging.log4j.spi.LoggerContext;
22  import org.apache.logging.log4j.spi.LoggerContextFactory;
23  import org.apache.logging.log4j.status.StatusLogger;
24  import org.apache.logging.log4j.util.LoaderUtil;
25  
26  public class SLF4JLoggerContextFactory implements LoggerContextFactory {
27      private static final StatusLogger LOGGER = StatusLogger.getLogger();
28      private static final LoggerContext context = new SLF4JLoggerContext();
29  
30      public SLF4JLoggerContextFactory() {
31          // LOG4J2-230, LOG4J2-204 (improve error reporting when misconfigured)
32          boolean misconfigured = false;
33          try {
34              LoaderUtil.loadClass("org.slf4j.helpers.Log4jLoggerFactory");
35              misconfigured = true;
36          } catch (final ClassNotFoundException classNotFoundIsGood) {
37              LOGGER.debug("org.slf4j.helpers.Log4jLoggerFactory is not on classpath. Good!");
38          }
39          if (misconfigured) {
40              throw new IllegalStateException("slf4j-impl jar is mutually exclusive with log4j-to-slf4j jar "
41                      + "(the first routes calls from SLF4J to Log4j, the second from Log4j to SLF4J)");
42          }
43      }
44  
45      @Override
46      public LoggerContext getContext(final String fqcn, final ClassLoader loader, final Object externalContext,
47                                      final boolean currentContext) {
48          return context;
49      }
50  
51      @Override
52      public LoggerContext getContext(final String fqcn, final ClassLoader loader, final Object externalContext,
53                                      final boolean currentContext, final URI configLocation, final String name) {
54          return context;
55      }
56  
57      @Override
58      public void removeContext(final LoggerContext ignored) {
59      }
60  
61      @Override
62      public boolean isClassLoaderDependent() {
63          // context is always used
64          return false;
65      }
66  }