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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  
20  import org.apache.logging.log4j.LogManager;
21  import org.apache.logging.log4j.core.LogEvent;
22  import org.apache.logging.log4j.core.LoggerContext;
23  import org.apache.logging.log4j.core.config.plugins.Plugin;
24  import org.apache.logging.log4j.core.impl.ContextAnchor;
25  
26  import javax.servlet.ServletContext;
27  
28  
29  @Plugin(name = "web", category = "Lookup")
30  public class WebLookup implements StrLookup {
31      private static final String ATTR_PREFIX = "attr.";
32      private static final String INIT_PARAM_PREFIX = "initParam.";
33  
34      protected ServletContext getServletContext() {
35          LoggerContext lc = ContextAnchor.THREAD_CONTEXT.get();
36          if (lc == null) {
37              lc = (LoggerContext) LogManager.getContext(false);
38          }
39          if (lc != null) {
40              Object obj = lc.getExternalContext();
41              return obj != null && obj instanceof ServletContext ? (ServletContext) obj : null;
42          }
43          return null;
44      }
45  
46      @Override
47      public String lookup(String key) {
48          ServletContext ctx = getServletContext();
49          if (ctx == null) {
50              return null;
51          }
52  
53          if (key.startsWith(ATTR_PREFIX)) {
54              String attrName = key.substring(ATTR_PREFIX.length());
55              Object attrValue = ctx.getAttribute(attrName);
56              return attrValue == null ? null : attrValue.toString();
57          }
58  
59          if (key.startsWith(INIT_PARAM_PREFIX)) {
60              String paramName = key.substring(INIT_PARAM_PREFIX.length());
61              return ctx.getInitParameter(paramName);
62          }
63  
64          if ("rootDir".equals(key)) {
65              String root = ctx.getRealPath("/");
66              if (root == null) {
67                  String msg = "failed to resolve web:rootDir -- " +
68                          "servlet container unable to translate virtual path " +
69                          " to real path (probably not deployed as exploded";
70                  throw new RuntimeException(msg);
71  
72              }
73              return root;
74          }
75  
76          if ("contextPath".equals(key)) {
77              return ctx.getContextPath();
78          }
79  
80          if ("servletContextName".equals(key)) {
81              return ctx.getServletContextName();
82          }
83  
84          if ("serverInfo".equals(key)) {
85              return ctx.getServerInfo();
86          }
87  
88          if ("effectiveMajorVersion".equals(key)) {
89              return String.valueOf(ctx.getEffectiveMajorVersion());
90          }
91  
92          if ("effectiveMinorVersion".equals(key)) {
93              return String.valueOf(ctx.getEffectiveMinorVersion());
94          }
95  
96          if ("majorVersion".equals(key)) {
97              return String.valueOf(ctx.getMajorVersion());
98          }
99  
100         if ("minorVersion".equals(key)) {
101             return String.valueOf(ctx.getMinorVersion());
102         }
103 
104         if (ctx.getAttribute(key) != null) {
105             return ctx.getAttribute(key).toString();
106         }
107 
108         if (ctx.getInitParameter(key) != null) {
109             return ctx.getInitParameter(key);
110         }
111 
112         ctx.log(getClass().getName() + " unable to resolve key '" + key + "'");
113         return null;
114     }
115 
116     @Override
117     public String lookup(LogEvent event, String key) {
118         return lookup(key);
119     }
120 }