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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.web;
18  
19  import java.net.URI;
20  import java.net.URL;
21  import java.text.SimpleDateFormat;
22  import java.util.ArrayList;
23  import java.util.Arrays;
24  import java.util.Date;
25  import java.util.List;
26  import java.util.Map;
27  import java.util.concurrent.ConcurrentHashMap;
28  import java.util.concurrent.TimeUnit;
29  
30  import javax.servlet.ServletContext;
31  
32  import org.apache.logging.log4j.LogManager;
33  import org.apache.logging.log4j.core.AbstractLifeCycle;
34  import org.apache.logging.log4j.core.LoggerContext;
35  import org.apache.logging.log4j.core.async.AsyncLoggerContext;
36  import org.apache.logging.log4j.core.config.Configurator;
37  import org.apache.logging.log4j.core.impl.ContextAnchor;
38  import org.apache.logging.log4j.core.impl.Log4jContextFactory;
39  import org.apache.logging.log4j.core.lookup.Interpolator;
40  import org.apache.logging.log4j.core.lookup.StrSubstitutor;
41  import org.apache.logging.log4j.core.selector.ContextSelector;
42  import org.apache.logging.log4j.core.selector.NamedContextSelector;
43  import org.apache.logging.log4j.core.util.Loader;
44  import org.apache.logging.log4j.core.util.NetUtils;
45  import org.apache.logging.log4j.core.util.SetUtils;
46  import org.apache.logging.log4j.spi.LoggerContextFactory;
47  import org.apache.logging.log4j.util.LoaderUtil;
48  
49  /**
50   * This class initializes and deinitializes Log4j no matter how the initialization occurs.
51   */
52  final class Log4jWebInitializerImpl extends AbstractLifeCycle implements Log4jWebLifeCycle {
53  
54      private static final String WEB_INF = "/WEB-INF/";
55  
56      static {
57          if (Loader.isClassAvailable("org.apache.logging.log4j.core.web.JNDIContextFilter")) {
58              throw new IllegalStateException("You are using Log4j 2 in a web application with the old, extinct "
59                      + "log4j-web artifact. This is not supported and could cause serious runtime problems. Please"
60                      + "remove the log4j-web JAR file from your application.");
61          }
62      }
63  
64      private final Map<String, String> map = new ConcurrentHashMap<>();
65      private final StrSubstitutor substitutor = new StrSubstitutor(new Interpolator(map));
66      private final ServletContext servletContext;
67  
68      private String name;
69      private NamedContextSelector namedContextSelector;
70      private LoggerContext loggerContext;
71  
72      private Log4jWebInitializerImpl(final ServletContext servletContext) {
73          this.servletContext = servletContext;
74          this.map.put("hostName", NetUtils.getLocalHostname());
75      }
76  
77      /**
78       * Initializes the Log4jWebLifeCycle attribute of a ServletContext. Those who wish to obtain this object should use
79       * the {@link org.apache.logging.log4j.web.WebLoggerContextUtils#getWebLifeCycle(javax.servlet.ServletContext)}
80       * method instead.
81       *
82       * @param servletContext
83       *        the ServletContext to initialize
84       * @return a new Log4jWebLifeCycle
85       * @since 2.0.1
86       */
87      protected static Log4jWebInitializerImpl initialize(final ServletContext servletContext) {
88          final Log4jWebInitializerImpl initializer = new Log4jWebInitializerImpl(servletContext);
89          servletContext.setAttribute(SUPPORT_ATTRIBUTE, initializer);
90          return initializer;
91      }
92  
93      @Override
94      public synchronized void start() {
95          if (this.isStopped() || this.isStopping()) {
96              throw new IllegalStateException("Cannot start this Log4jWebInitializerImpl after it was stopped.");
97          }
98  
99          // only do this once
100         if (this.isInitialized()) {
101             super.setStarting();
102 
103             this.name = this.substitutor.replace(this.servletContext.getInitParameter(LOG4J_CONTEXT_NAME));
104             final String location = this.substitutor.replace(this.servletContext
105                     .getInitParameter(LOG4J_CONFIG_LOCATION));
106             final boolean isJndi = "true".equalsIgnoreCase(this.servletContext
107                     .getInitParameter(IS_LOG4J_CONTEXT_SELECTOR_NAMED));
108 
109             if (isJndi) {
110                 this.initializeJndi(location);
111             } else {
112                 this.initializeNonJndi(location);
113             }
114             if (this.loggerContext instanceof AsyncLoggerContext) {
115                 ((AsyncLoggerContext) this.loggerContext).setUseThreadLocals(false);
116             }
117 
118             this.servletContext.setAttribute(CONTEXT_ATTRIBUTE, this.loggerContext);
119             super.setStarted();
120         }
121     }
122 
123     private void initializeJndi(final String location) {
124         final URI configLocation = getConfigURI(location);
125 
126         if (this.name == null) {
127             throw new IllegalStateException("A log4jContextName context parameter is required");
128         }
129 
130         LoggerContext context;
131         final LoggerContextFactory factory = LogManager.getFactory();
132         if (factory instanceof Log4jContextFactory) {
133             final ContextSelector selector = ((Log4jContextFactory) factory).getSelector();
134             if (selector instanceof NamedContextSelector) {
135                 this.namedContextSelector = (NamedContextSelector) selector;
136                 context = this.namedContextSelector.locateContext(this.name, this.servletContext, configLocation);
137                 ContextAnchor.THREAD_CONTEXT.set(context);
138                 if (context.isInitialized()) {
139                     context.start();
140                 }
141                 ContextAnchor.THREAD_CONTEXT.remove();
142             } else {
143                 LOGGER.warn("Potential problem: Selector is not an instance of NamedContextSelector.");
144                 return;
145             }
146         } else {
147             LOGGER.warn("Potential problem: LoggerContextFactory is not an instance of Log4jContextFactory.");
148             return;
149         }
150         this.loggerContext = context;
151         LOGGER.debug("Created logger context for [{}] using [{}].", this.name, context.getClass().getClassLoader());
152     }
153 
154     private void initializeNonJndi(final String location) {
155         if (this.name == null) {
156             this.name = this.servletContext.getServletContextName();
157             LOGGER.debug("Using the servlet context name \"{}\".", this.name);
158         }
159         if (this.name == null) {
160             this.name = this.servletContext.getContextPath();
161             LOGGER.debug("Using the servlet context context-path \"{}\".", this.name);
162         }
163         if (this.name == null && location == null) {
164             LOGGER.error("No Log4j context configuration provided. This is very unusual.");
165             this.name = new SimpleDateFormat("yyyyMMdd_HHmmss.SSS").format(new Date());
166         }
167         if (location != null && location.contains(",")) {
168             final List<URI> uris = getConfigURIs(location);
169             this.loggerContext = Configurator.initialize(this.name, this.getClassLoader(), uris, this.servletContext);
170             return;
171         }
172 
173         final URI uri = getConfigURI(location);
174         this.loggerContext = Configurator.initialize(this.name, this.getClassLoader(), uri, this.servletContext);
175     }
176 
177     private List<URI> getConfigURIs(final String location) {
178         final String[] parts = location.split(",");
179         final List<URI> uris = new ArrayList<>(parts.length);
180         for (final String part : parts) {
181             final URI uri = getConfigURI(part);
182             if (uri != null) {
183                 uris.add(uri);
184             }
185         }
186         return uris;
187     }
188 
189     private URI getConfigURI(final String location) {
190         try {
191             String configLocation = location;
192             if (configLocation == null) {
193                 final String[] paths = SetUtils.prefixSet(servletContext.getResourcePaths(WEB_INF), WEB_INF + "log4j2");
194                 LOGGER.debug("getConfigURI found resource paths {} in servletContext at [{}]", Arrays.toString(paths), WEB_INF);
195                 if (paths.length == 1) {
196                     configLocation = paths[0];
197                 } else if (paths.length > 1) {
198                     final String prefix = WEB_INF + "log4j2-" + this.name + ".";
199                     boolean found = false;
200                     for (final String str : paths) {
201                         if (str.startsWith(prefix)) {
202                             configLocation = str;
203                             found = true;
204                             break;
205                         }
206                     }
207                     if (!found) {
208                         configLocation = paths[0];
209                     }
210                 }
211             }
212             if (configLocation != null) {
213                 final URL url = servletContext.getResource(configLocation);
214                 if (url != null) {
215                     final URI uri = url.toURI();
216                     LOGGER.debug("getConfigURI found resource [{}] in servletContext at [{}]", uri, configLocation);
217                     return uri;
218                 }
219             }
220         } catch (final Exception ex) {
221             // Just try passing the location.
222         }
223         if (location != null) {
224             try {
225                 final URI correctedFilePathUri = NetUtils.toURI(location);
226                 LOGGER.debug("getConfigURI found [{}] in servletContext at [{}]", correctedFilePathUri, location);
227                 return correctedFilePathUri;
228             } catch (final Exception e) {
229                 LOGGER.error("Unable to convert configuration location [{}] to a URI", location, e);
230             }
231         }
232         return null;
233     }
234 
235     @Override
236     public synchronized boolean stop(final long timeout, final TimeUnit timeUnit) {
237         if (!this.isStarted() && !this.isStopped()) {
238             throw new IllegalStateException("Cannot stop this Log4jWebInitializer because it has not started.");
239         }
240 
241         // only do this once
242         if (this.isStarted()) {
243             this.setStopping();
244             if (this.loggerContext != null) {
245                 LOGGER.debug("Removing LoggerContext for [{}].", this.name);
246                 this.servletContext.removeAttribute(CONTEXT_ATTRIBUTE);
247                 if (this.namedContextSelector != null) {
248                     this.namedContextSelector.removeContext(this.name);
249                 }
250                 this.loggerContext.stop(timeout, timeUnit);
251                 this.loggerContext.setExternalContext(null);
252                 this.loggerContext = null;
253             }
254             this.setStopped();
255         }
256         return super.stop(timeout, timeUnit);
257     }
258 
259     @Override
260     public void setLoggerContext() {
261         if (this.loggerContext != null) {
262             ContextAnchor.THREAD_CONTEXT.set(this.loggerContext);
263         }
264     }
265 
266     @Override
267     public void clearLoggerContext() {
268         ContextAnchor.THREAD_CONTEXT.remove();
269     }
270 
271     @Override
272     public void wrapExecution(final Runnable runnable) {
273         this.setLoggerContext();
274 
275         try {
276             runnable.run();
277         } finally {
278             this.clearLoggerContext();
279         }
280     }
281 
282     private ClassLoader getClassLoader() {
283         try {
284             // if container is Servlet 3.0, use its getClassLoader method
285             // this may look odd, but the call below will throw NoSuchMethodError if user is on Servlet 2.5
286             // we compile against 3.0 to support Log4jServletContainerInitializer, but we don't require 3.0
287             return this.servletContext.getClassLoader();
288         } catch (final Throwable ignore) {
289             // LOG4J2-248: use TCCL if possible
290             return LoaderUtil.getThreadContextClassLoader();
291         }
292     }
293 
294 }