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/db/ColumnMapping.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.db;

import java.util.Date;
import java.util.Locale;

import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.core.Core;
import org.apache.logging.log4j.core.StringLayout;
import org.apache.logging.log4j.core.config.Configuration;
import org.apache.logging.log4j.core.config.plugins.Plugin;
import org.apache.logging.log4j.core.config.plugins.PluginBuilderAttribute;
import org.apache.logging.log4j.core.config.plugins.PluginBuilderFactory;
import org.apache.logging.log4j.core.config.plugins.PluginConfiguration;
import org.apache.logging.log4j.core.config.plugins.PluginElement;
import org.apache.logging.log4j.core.config.plugins.validation.constraints.Required;
import org.apache.logging.log4j.core.layout.PatternLayout;
import org.apache.logging.log4j.spi.ThreadContextMap;
import org.apache.logging.log4j.spi.ThreadContextStack;
import org.apache.logging.log4j.status.StatusLogger;
import org.apache.logging.log4j.util.ReadOnlyStringMap;

/**
 * A configuration element for specifying a database column name mapping.
 *
 * @since 2.8
 */
@Plugin(name = "ColumnMapping", category = Core.CATEGORY_NAME, printObject = true)
public class ColumnMapping {

    /**
     * Builder for {@link ColumnMapping}.
     */
    public static class Builder implements org.apache.logging.log4j.core.util.Builder<ColumnMapping> {

        @PluginConfiguration
        private Configuration configuration;

        @PluginElement("Layout")
        private StringLayout layout;

        @PluginBuilderAttribute
        private String literal;

        @PluginBuilderAttribute
        @Required(message = "No column name provided")
        private String name;

        @PluginBuilderAttribute
        private String parameter;

        @PluginBuilderAttribute
        private String pattern;

        @PluginBuilderAttribute
        private String source;

        @PluginBuilderAttribute
        @Required(message = "No conversion type provided")
        private Class<?> type = String.class;

        @Override
        public ColumnMapping build() {
            if (pattern != null) {
                layout = PatternLayout.newBuilder()
                    .withPattern(pattern)
                    .withConfiguration(configuration)
                    .withAlwaysWriteExceptions(false)
                    .build();
            }
            if (!(layout == null
                || literal == null
                || Date.class.isAssignableFrom(type)
                || ReadOnlyStringMap.class.isAssignableFrom(type)
                || ThreadContextMap.class.isAssignableFrom(type)
                || ThreadContextStack.class.isAssignableFrom(type))) {
                LOGGER.error("No 'layout' or 'literal' value specified and type ({}) is not compatible with ThreadContextMap, ThreadContextStack, or java.util.Date for the mapping", type, this);
                return null;
            }
            if (literal != null && parameter != null) {
                LOGGER.error("Only one of 'literal' or 'parameter' can be set on the column mapping {}", this);
                return null;
            }
            return new ColumnMapping(name, source, layout, literal, parameter, type);
        }

        public Builder setConfiguration(final Configuration configuration) {
            this.configuration = configuration;
            return this;
        }

        /**
         * Layout of value to write to database (before type conversion). Not applicable if {@link #setType(Class)} is
         * a {@link ReadOnlyStringMap}, {@link ThreadContextMap}, or {@link ThreadContextStack}.
         *
         * @return this.
         */
        public Builder setLayout(final StringLayout layout) {
            this.layout = layout;
            return this;
        }

        /**
         * Literal value to use for populating a column. This is generally useful for functions, stored procedures,
         * etc. No escaping will be done on this value.
         *
         * @return this.
         */
        public Builder setLiteral(final String literal) {
            this.literal = literal;
            return this;
        }

        /**
         * Column name.
         *
         * @return this.
         */
        public Builder setName(final String name) {
            this.name = name;
            return this;
        }

        /**
         * Parameter value to use for populating a column, MUST contain a single parameter marker '?'. This is generally useful for functions, stored procedures,
         * etc. No escaping will be done on this value.
         *
         * @return this.
         */
        public Builder setParameter(final String parameter) {
            this.parameter= parameter;
            return this;
        }

        /**
         * Pattern to use as a {@link PatternLayout}. Convenient shorthand for {@link #setLayout(StringLayout)} with a
         * PatternLayout.
         *
         * @return this.
         */
        public Builder setPattern(final String pattern) {
            this.pattern = pattern;
            return this;
        }

        /**
         * Source name. Useful when combined with a {@link org.apache.logging.log4j.message.MapMessage} depending on the
         * appender.
         *
         * @return this.
         */
        public Builder setSource(final String source) {
            this.source = source;
            return this;
        }

        /**
         * Class to convert value to before storing in database. If the type is compatible with {@link ThreadContextMap} or
         * {@link ReadOnlyStringMap}, then the MDC will be used. If the type is compatible with {@link ThreadContextStack},
         * then the NDC will be used. If the type is compatible with {@link Date}, then the event timestamp will be used.
         *
         * @return this.
         */
        public Builder setType(final Class<?> type) {
            this.type = type;
            return this;
        }

        @Override
        public String toString() {
            return "Builder [name=" + name + ", source=" + source + ", literal=" + literal + ", parameter=" + parameter
                    + ", pattern=" + pattern + ", type=" + type + ", layout=" + layout + "]";
        }
    }

    private static final Logger LOGGER = StatusLogger.getLogger();

    @PluginBuilderFactory
    public static Builder newBuilder() {
        return new Builder();
    }

    public static String toKey(final String name) {
        return name.toUpperCase(Locale.ROOT);
    }

    private final StringLayout layout;
    private final String literalValue;
    private final String name;
    private final String nameKey;
    private final String parameter;
    private final String source;
    private final Class<?> type;

    private ColumnMapping(final String name, final String source, final StringLayout layout, final String literalValue, final String parameter, final Class<?> type) {
        this.name = name;
        this.nameKey = toKey(name);
        this.source = source;
        this.layout = layout;
        this.literalValue = literalValue;
        this.parameter = parameter;
        this.type = type;
    }

    public StringLayout getLayout() {
        return layout;
    }

    public String getLiteralValue() {
        return literalValue;
    }

    public String getName() {
        return name;
    }

    public String getNameKey() {
        return nameKey;
    }

    public String getParameter() {
        return parameter;
    }

    public String getSource() {
        return source;
    }

    public Class<?> getType() {
        return type;
    }

    @Override
    public String toString() {
        return "ColumnMapping [name=" + name + ", source=" + source + ", literalValue=" + literalValue + ", parameter="
                + parameter + ", type=" + type + ", layout=" + layout + "]";
    }

}

⏎ org/apache/logging/log4j/core/appender/db/ColumnMapping.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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