001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache license, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the license for the specific language governing permissions and
015 * limitations under the license.
016 */
017 package org.apache.logging.log4j.core.impl;
018
019 import java.net.URI;
020
021 import org.apache.logging.log4j.core.LifeCycle;
022 import org.apache.logging.log4j.core.LoggerContext;
023 import org.apache.logging.log4j.core.config.Configuration;
024 import org.apache.logging.log4j.core.config.ConfigurationFactory;
025 import org.apache.logging.log4j.core.config.ConfigurationSource;
026 import org.apache.logging.log4j.core.selector.ClassLoaderContextSelector;
027 import org.apache.logging.log4j.core.selector.ContextSelector;
028 import org.apache.logging.log4j.core.util.Assert;
029 import org.apache.logging.log4j.core.util.Cancellable;
030 import org.apache.logging.log4j.core.util.Constants;
031 import org.apache.logging.log4j.core.util.DefaultShutdownCallbackRegistry;
032 import org.apache.logging.log4j.core.util.Loader;
033 import org.apache.logging.log4j.core.util.ShutdownCallbackRegistry;
034 import org.apache.logging.log4j.spi.LoggerContextFactory;
035 import org.apache.logging.log4j.status.StatusLogger;
036 import org.apache.logging.log4j.util.PropertiesUtil;
037
038 /**
039 * Factory to locate a ContextSelector and then load a LoggerContext.
040 */
041 public class Log4jContextFactory implements LoggerContextFactory, ShutdownCallbackRegistry {
042
043 private static final StatusLogger LOGGER = StatusLogger.getLogger();
044 private static final boolean SHUTDOWN_HOOK_ENABLED =
045 PropertiesUtil.getProperties().getBooleanProperty(ShutdownCallbackRegistry.SHUTDOWN_HOOK_ENABLED, true);
046
047 private final ContextSelector selector;
048 private final ShutdownCallbackRegistry shutdownCallbackRegistry;
049
050 /**
051 * Initializes the ContextSelector from system property {@link Constants#LOG4J_CONTEXT_SELECTOR}.
052 */
053 public Log4jContextFactory() {
054 this(createContextSelector(), createShutdownCallbackRegistry());
055 }
056
057 /**
058 * Initializes this factory's ContextSelector with the specified selector.
059 * @param selector the selector to use
060 */
061 public Log4jContextFactory(final ContextSelector selector) {
062 this(selector, createShutdownCallbackRegistry());
063 }
064
065 /**
066 * Constructs a Log4jContextFactory using the ContextSelector from {@link Constants#LOG4J_CONTEXT_SELECTOR}
067 * and the provided ShutdownRegistrationStrategy.
068 *
069 * @param shutdownCallbackRegistry the ShutdownRegistrationStrategy to use
070 * @since 2.1
071 */
072 public Log4jContextFactory(final ShutdownCallbackRegistry shutdownCallbackRegistry) {
073 this(createContextSelector(), shutdownCallbackRegistry);
074 }
075
076 /**
077 * Constructs a Log4jContextFactory using the provided ContextSelector and ShutdownRegistrationStrategy.
078 *
079 * @param selector the selector to use
080 * @param shutdownCallbackRegistry the ShutdownRegistrationStrategy to use
081 * @since 2.1
082 */
083 public Log4jContextFactory(final ContextSelector selector,
084 final ShutdownCallbackRegistry shutdownCallbackRegistry) {
085 this.selector = Assert.requireNonNull(selector, "No ContextSelector provided");
086 this.shutdownCallbackRegistry = Assert.requireNonNull(shutdownCallbackRegistry,
087 "No ShutdownCallbackRegistry provided");
088 LOGGER.debug("Using ShutdownCallbackRegistry {}", shutdownCallbackRegistry.getClass());
089 initializeShutdownCallbackRegistry();
090 }
091
092 private static ContextSelector createContextSelector() {
093 final String sel = PropertiesUtil.getProperties().getStringProperty(Constants.LOG4J_CONTEXT_SELECTOR);
094 if (sel != null) {
095 try {
096 return Loader.newCheckedInstanceOf(sel, ContextSelector.class);
097 } catch (final Exception ex) {
098 LOGGER.error("Unable to create context {}", sel, ex);
099 }
100 }
101 return new ClassLoaderContextSelector();
102 }
103
104 private static ShutdownCallbackRegistry createShutdownCallbackRegistry() {
105 // TODO: this is such a common idiom it really deserves a utility method somewhere
106 final String registry = PropertiesUtil.getProperties().getStringProperty(
107 ShutdownCallbackRegistry.SHUTDOWN_CALLBACK_REGISTRY);
108 if (registry != null) {
109 try {
110 return Loader.newCheckedInstanceOf(registry, ShutdownCallbackRegistry.class);
111 } catch (final Exception e) {
112 LOGGER.error(SHUTDOWN_HOOK_MARKER,
113 "There was an error loading the ShutdownCallbackRegistry [{}]. "
114 + "Falling back to DefaultShutdownCallbackRegistry.", registry, e);
115 }
116 }
117 return new DefaultShutdownCallbackRegistry();
118 }
119
120 private void initializeShutdownCallbackRegistry() {
121 if (SHUTDOWN_HOOK_ENABLED && this.shutdownCallbackRegistry instanceof LifeCycle) {
122 try {
123 ((LifeCycle) this.shutdownCallbackRegistry).start();
124 } catch (final Exception e) {
125 LOGGER.error("There was an error starting the ShutdownCallbackRegistry.", e);
126 }
127 }
128 }
129
130 /**
131 * Loads the LoggerContext using the ContextSelector.
132 * @param fqcn The fully qualified class name of the caller.
133 * @param loader The ClassLoader to use or null.
134 * @param currentContext If true returns the current Context, if false returns the Context appropriate
135 * for the caller if a more appropriate Context can be determined.
136 * @param externalContext An external context (such as a ServletContext) to be associated with the LoggerContext.
137 * @return The LoggerContext.
138 */
139 @Override
140 public LoggerContext getContext(final String fqcn, final ClassLoader loader, final Object externalContext,
141 final boolean currentContext) {
142 final LoggerContext ctx = selector.getContext(fqcn, loader, currentContext);
143 if (externalContext != null && ctx.getExternalContext() == null) {
144 ctx.setExternalContext(externalContext);
145 }
146 if (ctx.getState() == LifeCycle.State.INITIALIZED) {
147 ctx.start();
148 }
149 return ctx;
150 }
151
152 /**
153 * Loads the LoggerContext using the ContextSelector.
154 * @param fqcn The fully qualified class name of the caller.
155 * @param loader The ClassLoader to use or null.
156 * @param externalContext An external context (such as a ServletContext) to be associated with the LoggerContext.
157 * @param currentContext If true returns the current Context, if false returns the Context appropriate
158 * for the caller if a more appropriate Context can be determined.
159 * @param source The configuration source.
160 * @return The LoggerContext.
161 */
162 public LoggerContext getContext(final String fqcn, final ClassLoader loader, final Object externalContext,
163 final boolean currentContext, final ConfigurationSource source) {
164 final LoggerContext ctx = selector.getContext(fqcn, loader, currentContext, null);
165 if (externalContext != null && ctx.getExternalContext() == null) {
166 ctx.setExternalContext(externalContext);
167 }
168 if (ctx.getState() == LifeCycle.State.INITIALIZED) {
169 if (source != null) {
170 ContextAnchor.THREAD_CONTEXT.set(ctx);
171 final Configuration config = ConfigurationFactory.getInstance().getConfiguration(source);
172 LOGGER.debug("Starting LoggerContext[name={}] from configuration {}", ctx.getName(), source);
173 ctx.start(config);
174 ContextAnchor.THREAD_CONTEXT.remove();
175 } else {
176 ctx.start();
177 }
178 }
179 return ctx;
180 }
181
182 /**
183 * Loads the LoggerContext using the ContextSelector.
184 * @param fqcn The fully qualified class name of the caller.
185 * @param loader The ClassLoader to use or null.
186 * @param externalContext An external context (such as a ServletContext) to be associated with the LoggerContext.
187 * @param currentContext If true returns the current Context, if false returns the Context appropriate
188 * for the caller if a more appropriate Context can be determined.
189 * @param configLocation The location of the configuration for the LoggerContext.
190 * @return The LoggerContext.
191 */
192 @Override
193 public LoggerContext getContext(final String fqcn, final ClassLoader loader, final Object externalContext,
194 final boolean currentContext, final URI configLocation, final String name) {
195 final LoggerContext ctx = selector.getContext(fqcn, loader, currentContext, configLocation);
196 if (externalContext != null && ctx.getExternalContext() == null) {
197 ctx.setExternalContext(externalContext);
198 }
199 if (ctx.getState() == LifeCycle.State.INITIALIZED) {
200 if (configLocation != null || name != null) {
201 ContextAnchor.THREAD_CONTEXT.set(ctx);
202 final Configuration config = ConfigurationFactory.getInstance().getConfiguration(name, configLocation);
203 LOGGER.debug("Starting LoggerContext[name={}] from configuration at {}", ctx.getName(), configLocation);
204 ctx.start(config);
205 ContextAnchor.THREAD_CONTEXT.remove();
206 } else {
207 ctx.start();
208 }
209 }
210 return ctx;
211 }
212
213 /**
214 * Returns the ContextSelector.
215 * @return The ContextSelector.
216 */
217 public ContextSelector getSelector() {
218 return selector;
219 }
220
221 /**
222 * Removes knowledge of a LoggerContext.
223 *
224 * @param context The context to remove.
225 */
226 @Override
227 public void removeContext(final org.apache.logging.log4j.spi.LoggerContext context) {
228 if (context instanceof LoggerContext) {
229 selector.removeContext((LoggerContext) context);
230 }
231 }
232
233 @Override
234 public Cancellable addShutdownCallback(final Runnable callback) {
235 return SHUTDOWN_HOOK_ENABLED ? shutdownCallbackRegistry.addShutdownCallback(callback) : null;
236 }
237 }