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/LogEventJsonMixIn.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 java.util.Map;

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.time.Instant;
import org.apache.logging.log4j.util.ReadOnlyStringMap;
import org.apache.logging.log4j.core.LogEvent;
import org.apache.logging.log4j.core.impl.ThrowableProxy;
import org.apache.logging.log4j.message.Message;

import com.fasterxml.jackson.annotation.JsonFilter;
import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonPropertyOrder;
import com.fasterxml.jackson.annotation.JsonRootName;
import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlElementWrapper;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlProperty;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlRootElement;

@JsonRootName(XmlConstants.ELT_EVENT)
@JacksonXmlRootElement(namespace = XmlConstants.XML_NAMESPACE, localName = XmlConstants.ELT_EVENT)
@JsonFilter("org.apache.logging.log4j.core.impl.Log4jLogEvent")
@JsonPropertyOrder({ "timeMillis", JsonConstants.ELT_INSTANT, "threadName", "level", "loggerName", "marker", "message", "thrown", XmlConstants.ELT_CONTEXT_MAP,
        JsonConstants.ELT_CONTEXT_STACK, "loggerFQCN", "Source", "endOfBatch" })
abstract class LogEventJsonMixIn implements LogEvent {

    private static final long serialVersionUID = 1L;

//    @JsonProperty(JsonConstants.ELT_CONTEXT_MAP)
//    @JacksonXmlProperty(namespace = XmlConstants.XML_NAMESPACE, localName = XmlConstants.ELT_CONTEXT_MAP)
//    @JsonSerialize(using = MapSerializer.class)
//    @JsonDeserialize(using = MapDeserializer.class)
    @Override
    @JsonIgnore
//    @JsonProperty(JsonConstants.ELT_CONTEXT_MAP)
//    @JacksonXmlProperty(namespace = XmlConstants.XML_NAMESPACE, localName = XmlConstants.ELT_CONTEXT_MAP)
    public abstract Map<String, String> getContextMap();

    @JsonProperty(JsonConstants.ELT_CONTEXT_MAP)
    @JacksonXmlProperty(namespace = XmlConstants.XML_NAMESPACE, localName = XmlConstants.ELT_CONTEXT_MAP)
    @JsonSerialize(using = ContextDataSerializer.class)
    @JsonDeserialize(using = ContextDataDeserializer.class)
    //@JsonIgnore
    @Override
    public abstract ReadOnlyStringMap getContextData();

    @JsonProperty(JsonConstants.ELT_CONTEXT_STACK)
    @JacksonXmlElementWrapper(namespace = XmlConstants.XML_NAMESPACE, localName = XmlConstants.ELT_CONTEXT_STACK)
    @JacksonXmlProperty(namespace = XmlConstants.XML_NAMESPACE, localName = XmlConstants.ELT_CONTEXT_STACK_ITEM)
    @Override
    public abstract ContextStack getContextStack();

    @JsonProperty()
    @JacksonXmlProperty(isAttribute = true)
    @Override
    public abstract Level getLevel();

    @JsonProperty()
    @JacksonXmlProperty(isAttribute = true)
    @Override
    public abstract String getLoggerFqcn();

    @JsonProperty()
    @JacksonXmlProperty(isAttribute = true)
    @Override
    public abstract String getLoggerName();

    @JsonProperty(JsonConstants.ELT_MARKER)
    @JacksonXmlProperty(namespace = XmlConstants.XML_NAMESPACE, localName = XmlConstants.ELT_MARKER)
    @Override
    public abstract Marker getMarker();

    @JsonProperty(JsonConstants.ELT_MESSAGE)
    @JsonDeserialize(using = SimpleMessageDeserializer.class)
    @JacksonXmlProperty(namespace = XmlConstants.XML_NAMESPACE, localName = XmlConstants.ELT_MESSAGE)
    @Override
    public abstract Message getMessage();

    @JsonProperty(JsonConstants.ELT_SOURCE)
    @JsonDeserialize(using = Log4jStackTraceElementDeserializer.class)
    @JacksonXmlProperty(namespace = XmlConstants.XML_NAMESPACE, localName = XmlConstants.ELT_SOURCE)
    @Override
    public abstract StackTraceElement getSource();

    @Override
    @JsonProperty("threadId")
    @JacksonXmlProperty(isAttribute = true, localName = "threadId")
    public abstract long getThreadId();

    @Override
    @JsonProperty("thread")
    @JacksonXmlProperty(isAttribute = true, localName = "thread")
    public abstract String getThreadName();

    @Override
    @JsonProperty("threadPriority")
    @JacksonXmlProperty(isAttribute = true, localName = "threadPriority")
    public abstract int getThreadPriority();

    @JsonIgnore
    @Override
    public abstract Throwable getThrown();

    @JsonProperty(JsonConstants.ELT_THROWN)
    @JacksonXmlProperty(namespace = XmlConstants.XML_NAMESPACE, localName = XmlConstants.ELT_THROWN)
    @Override
    public abstract ThrowableProxy getThrownProxy();

    @JsonProperty(value = JsonConstants.ELT_TIME_MILLIS, access = JsonProperty.Access.READ_ONLY)
    @JacksonXmlProperty(isAttribute = true)
    @Override
    public abstract long getTimeMillis();

    @JsonProperty(JsonConstants.ELT_INSTANT)
    @JacksonXmlProperty(namespace = XmlConstants.XML_NAMESPACE, localName = XmlConstants.ELT_INSTANT)
    @Override
    public abstract Instant getInstant();

    @JsonProperty()
    @JacksonXmlProperty(isAttribute = true)
    @Override
    public abstract boolean isEndOfBatch();

    @JsonIgnore
    @Override
    public abstract boolean isIncludeLocation();

    @Override
    public abstract void setEndOfBatch(boolean endOfBatch);

    @Override
    public abstract void setIncludeLocation(boolean locationRequired);

}

⏎ org/apache/logging/log4j/core/jackson/LogEventJsonMixIn.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
Download 

⇒ Source Code for Apache Log4j JDK Logging Adapter

⇐ Source Code for Apache Log4j API

⇑ Downloading and Reviewing Apache Log4j Packages

⇑⇑ FAQ for Apache Log4j