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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.log4j.core.lookup;
18  
19  import java.util.MissingResourceException;
20  import java.util.ResourceBundle;
21  
22  import org.apache.logging.log4j.core.LogEvent;
23  import org.apache.logging.log4j.core.config.plugins.Plugin;
24  
25  /**
26   * Looks up keys from resource bundles.
27   */
28  @Plugin(name = "bundle", category = "Lookup")
29  public class ResourceBundleLookup implements StrLookup {
30  
31      /**
32       * Looks up the value for the key in the format "BundleName:BundleKey".
33       * 
34       * For example: "com.domain.messages:MyKey".
35       * 
36       * @param key
37       *            the key to be looked up, may be null
38       * @return The value for the key.
39       */
40      @Override
41      public String lookup(final String key) {
42          if (key == null) {
43              return null;
44          }
45          final String[] keys = key.split(":");
46          final int keyLen = keys.length;
47          if (keyLen != 2) {
48              // throw new IllegalArgumentException("Bad key format " + key + ", format is BundleName:Value");
49              // log?
50              return null;
51          }
52          final String bundleName = keys[0];
53          final String bundleKey = keys[1];
54          try {
55              // The ResourceBundle class caches bundles, no need to cache here.
56              return ResourceBundle.getBundle(bundleName).getString(bundleKey);
57          } catch (final MissingResourceException e) {
58              // log?
59              return null;
60          }
61      }
62  
63      /**
64       * Looks up the value for the key in the format "BundleName:BundleKey".
65       * 
66       * For example: "com.domain.messages:MyKey".
67       * 
68       * @param event
69       *            The current LogEvent.
70       * @param key
71       *            the key to be looked up, may be null
72       * @return The value associated with the key.
73       */
74      @Override
75      public String lookup(final LogEvent event, final String key) {
76          return lookup(key);
77      }
78  }