Apache Log4j Core Implementation provides the functional components of the logging system. Users are free to create their own plugins and include them in the logging configuration. Apache Log4j Core is a required module to use Apache Log4j.

Bytecode (Java 8) for Apache Log4j Core Implementation is provided in a separate JAR file like log4j-core-2.14.1.jar.

Source Code files for Apache Log4j API are provided in both binary packge like apache-log4j-2.14.1-bin.zip and source package like apache-log4j-2.14.1-src.zip. You can download them at Apache Log4j Website.

You can also browse Source Code files for Apache Log4j Core Implementation 2.14.1 below.

⏎ org/apache/logging/log4j/core/jackson/Initializers.java

/*
 * 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.jackson;

import org.apache.logging.log4j.Level;
import org.apache.logging.log4j.Marker;
import org.apache.logging.log4j.ThreadContext.ContextStack;
import org.apache.logging.log4j.core.LogEvent;
import org.apache.logging.log4j.core.impl.ExtendedStackTraceElement;
import org.apache.logging.log4j.core.impl.ThrowableProxy;
import org.apache.logging.log4j.message.Message;
import org.apache.logging.log4j.message.ObjectMessage;

import com.fasterxml.jackson.databind.Module.SetupContext;
import com.fasterxml.jackson.databind.module.SimpleModule;
import org.apache.logging.log4j.core.time.Instant;

/**
 * Initialization utils.
 * <p>
 * <em>Consider this class private.</em>
 * </p>
 */
class Initializers {

    /**
     * Used to set up {@link SetupContext} from different {@link SimpleModule}s.
     */
    static class SetupContextInitializer {

        void setupModule(final SetupContext context, final boolean includeStacktrace, final boolean stacktraceAsString) {
            // JRE classes: we cannot edit those with Jackson annotations
            context.setMixInAnnotations(StackTraceElement.class, StackTraceElementMixIn.class);
            // Log4j API classes: we do not want to edit those with Jackson annotations because the API module should not depend on Jackson.
            context.setMixInAnnotations(Marker.class, MarkerMixIn.class);
            context.setMixInAnnotations(Level.class, LevelMixIn.class);
            context.setMixInAnnotations(Instant.class, InstantMixIn.class);
            context.setMixInAnnotations(LogEvent.class, LogEventWithContextListMixIn.class);
            // Log4j Core classes: we do not want to bring in Jackson at runtime if we do not have to.
            context.setMixInAnnotations(ExtendedStackTraceElement.class, ExtendedStackTraceElementMixIn.class);
            context.setMixInAnnotations(ThrowableProxy.class,
                    includeStacktrace ? (stacktraceAsString ? ThrowableProxyWithStacktraceAsStringMixIn.class : ThrowableProxyMixIn.class ) : ThrowableProxyWithoutStacktraceMixIn.class);
        }
    }

    /**
     * Used to set up {@link SetupContext} from different {@link SimpleModule}s.
     * Differs from SetupContextInitializer by installing {@code LogEventJsonMixIn} for LogEvents,
     * not {@code LogEventMixIn}, so it handles ThreadContext serialization differently.
     */
    static class SetupContextJsonInitializer {

        void setupModule(final SetupContext context, final boolean includeStacktrace, final boolean stacktraceAsString) {
            // JRE classes: we cannot edit those with Jackson annotations
            context.setMixInAnnotations(StackTraceElement.class, StackTraceElementMixIn.class);
            // Log4j API classes: we do not want to edit those with Jackson annotations because the API module should not depend on Jackson.
            context.setMixInAnnotations(Marker.class, MarkerMixIn.class);
            context.setMixInAnnotations(Level.class, LevelMixIn.class);
            context.setMixInAnnotations(Instant.class, InstantMixIn.class);
            context.setMixInAnnotations(LogEvent.class, LogEventJsonMixIn.class); // different ThreadContext handling
            // Log4j Core classes: we do not want to bring in Jackson at runtime if we do not have to.
            context.setMixInAnnotations(ExtendedStackTraceElement.class, ExtendedStackTraceElementMixIn.class);
            context.setMixInAnnotations(ThrowableProxy.class,
                    includeStacktrace ? (stacktraceAsString ? ThrowableProxyWithStacktraceAsStringMixIn.class : ThrowableProxyMixIn.class ) : ThrowableProxyWithoutStacktraceMixIn.class);
        }
    }

    /**
     * Used to set up {@link SimpleModule} from different {@link SimpleModule} subclasses.
     */
    static class SimpleModuleInitializer {
        void initialize(final SimpleModule simpleModule, final boolean objectMessageAsJsonObject) {
            // Workaround because mix-ins do not work for classes that already have a built-in deserializer.
            // See Jackson issue 429.
            simpleModule.addDeserializer(StackTraceElement.class, new Log4jStackTraceElementDeserializer());
            simpleModule.addDeserializer(ContextStack.class, new MutableThreadContextStackDeserializer());
            if (objectMessageAsJsonObject) {
            	    simpleModule.addSerializer(ObjectMessage.class, new ObjectMessageSerializer());
            }
            simpleModule.addSerializer(Message.class, new MessageSerializer());
        }
    }

}

⏎ org/apache/logging/log4j/core/jackson/Initializers.java

Or download all of them as a single archive file:

File name: log4j-core-2.14.1-sources.jar
File size: 1281358 bytes
Release date: 2021-03-06
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