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/appender/nosql/NoSqlConnection.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.appender.nosql;

import java.io.Closeable;

/**
 * Represents a connection to the NoSQL database. Serves as a factory for new (empty) objects and an endpoint for
 * inserted objects.
 *
 * @param <T> Specifies which implementation of {@link NoSqlObject} this connection provides.
 * @param <W> Specifies which type of database object is wrapped by the {@link NoSqlObject} implementation provided.
 */
public interface NoSqlConnection<W, T extends NoSqlObject<W>> extends Closeable {
    /**
     * Instantiates and returns a {@link NoSqlObject} instance whose properties can be configured before ultimate
     * insertion via {@link #insertObject(NoSqlObject)}.
     *
     * @return a new object.
     * @see NoSqlObject
     */
    T createObject();

    /**
     * Creates an array of the specified length typed to match the {@link NoSqlObject} implementation appropriate for
     * this provider.
     *
     * @param length the length of the array to create.
     * @return a new array.
     * @see NoSqlObject
     */
    T[] createList(int length);

    /**
     * Inserts the given object into the underlying NoSQL database.
     *
     * @param object The object to insert.
     */
    void insertObject(NoSqlObject<W> object);

    /**
     * Closes the underlying connection. This method call should be idempotent. Only the first call should have any
     * effect; all further calls should be ignored. It's possible the underlying connection is stateless (such as an
     * HTTP web service), in which case this method would be a no-op. This method should also commit any open
     * transactions, if applicable and if not already committed.
     * <p>
     * If this connection is part of a connection pool, executing this method should commit the transaction and return
     * the connection to the pool, but it should not actually close the underlying connection.
     * </p>
     */
    @Override
    void close();

    /**
     * Indicates whether the underlying connection is closed. If the underlying connection is stateless (such as an
     * HTTP web service), this method would likely always return true. Essentially, this method should only return
     * {@code true} if a call to {@link #insertObject(NoSqlObject)} <b>will</b> fail due to the state of this object.
     *
     * @return {@code true} if this object is considered closed.
     */
    boolean isClosed();
}

⏎ org/apache/logging/log4j/core/appender/nosql/NoSqlConnection.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