| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache license, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the license for the specific language governing permissions and |
| * limitations under the license. |
| */ |
| package org.apache.logging.log4j.core.impl; |
| |
| import org.apache.logging.log4j.ThreadContext; |
| import org.apache.logging.log4j.core.ContextDataInjector; |
| import org.apache.logging.log4j.core.LogEvent; |
| import org.apache.logging.log4j.spi.CopyOnWrite; |
| import org.apache.logging.log4j.spi.DefaultThreadContextMap; |
| import org.apache.logging.log4j.spi.ReadOnlyThreadContextMap; |
| import org.apache.logging.log4j.status.StatusLogger; |
| import org.apache.logging.log4j.util.LoaderUtil; |
| import org.apache.logging.log4j.util.PropertiesUtil; |
| import org.apache.logging.log4j.util.ReadOnlyStringMap; |
| |
| /** |
| * Factory for ContextDataInjectors. Returns a new {@code ContextDataInjector} instance based on the value of system |
| * property {@code log4j2.ContextDataInjector}. Users may use this system property to specify the fully qualified class |
| * name of a class that implements the {@code ContextDataInjector} interface. |
| * If no value was specified this factory method returns one of the injectors defined in |
| * {@code ThreadContextDataInjector}. |
| * |
| * @see ContextDataInjector |
| * @see ReadOnlyStringMap |
| * @see ThreadContextDataInjector |
| * @see LogEvent#getContextData() |
| * @since 2.7 |
| */ |
| public class ContextDataInjectorFactory { |
| |
| /** |
| * Returns a new {@code ContextDataInjector} instance based on the value of system property |
| * {@code log4j2.ContextDataInjector}. If no value was specified this factory method returns one of the |
| * {@code ContextDataInjector} classes defined in {@link ThreadContextDataInjector} which is most appropriate for |
| * the ThreadContext implementation. |
| * <p> |
| * Users may use this system property to specify the fully qualified class name of a class that implements the |
| * {@code ContextDataInjector} interface. |
| * </p><p> |
| * When providing a custom {@code ContextDataInjector}, be aware that this method may be invoked multiple times by |
| * the various components in Log4j that need access to context data. |
| * This includes the object(s) that populate log events, but also various lookups and filters that look at |
| * context data to determine whether an event should be logged. |
| * </p> |
| * |
| * @return a ContextDataInjector that populates the {@code ReadOnlyStringMap} of all {@code LogEvent} objects |
| * @see LogEvent#getContextData() |
| * @see ContextDataInjector |
| */ |
| public static ContextDataInjector createInjector() { |
| final String className = PropertiesUtil.getProperties().getStringProperty("log4j2.ContextDataInjector"); |
| if (className == null) { |
| return createDefaultInjector(); |
| } |
| try { |
| final Class<? extends ContextDataInjector> cls = LoaderUtil.loadClass(className).asSubclass( |
| ContextDataInjector.class); |
| return cls.newInstance(); |
| } catch (final Exception dynamicFailed) { |
| final ContextDataInjector result = createDefaultInjector(); |
| StatusLogger.getLogger().warn( |
| "Could not create ContextDataInjector for '{}', using default {}: {}", |
| className, result.getClass().getName(), dynamicFailed); |
| return result; |
| } |
| } |
| |
| private static ContextDataInjector createDefaultInjector() { |
| final ReadOnlyThreadContextMap threadContextMap = ThreadContext.getThreadContextMap(); |
| |
| // note: map may be null (if legacy custom ThreadContextMap was installed by user) |
| if (threadContextMap instanceof DefaultThreadContextMap || threadContextMap == null) { |
| return new ThreadContextDataInjector.ForDefaultThreadContextMap(); // for non StringMap-based context maps |
| } |
| if (threadContextMap instanceof CopyOnWrite) { |
| return new ThreadContextDataInjector.ForCopyOnWriteThreadContextMap(); |
| } |
| return new ThreadContextDataInjector.ForGarbageFreeThreadContextMap(); |
| } |
| } |