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/filter/AbstractFilterable.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.filter;

import java.util.Iterator;
import java.util.concurrent.TimeUnit;

import org.apache.logging.log4j.core.AbstractLifeCycle;
import org.apache.logging.log4j.core.Filter;
import org.apache.logging.log4j.core.LifeCycle2;
import org.apache.logging.log4j.core.LogEvent;
import org.apache.logging.log4j.core.config.Property;
import org.apache.logging.log4j.core.config.plugins.PluginElement;

/**
 * Enhances a Class by allowing it to contain Filters.
 */
public abstract class AbstractFilterable extends AbstractLifeCycle implements Filterable {

    /**
     * Subclasses can extend this abstract Builder.
     *
     * @param <B> The type to build.
     */
    public abstract static class Builder<B extends Builder<B>> {

        @PluginElement("Filter")
        private Filter filter;

        // We are calling this attribute propertyArray because we use the more generic "properties" in several places
        // with different types: Array, Map and List.
        @PluginElement("Properties")
        private Property[] propertyArray;

        @SuppressWarnings("unchecked")
        public B asBuilder() {
            return (B) this;
        }

        public Filter getFilter() {
            return filter;
        }

        public Property[] getPropertyArray() {
            return propertyArray;
        }

        public B setFilter(final Filter filter) {
            this.filter = filter;
            return asBuilder();
        }

        public B setPropertyArray(final Property[] properties) {
            this.propertyArray = properties;
            return asBuilder();
        }

        /**
         * Sets the filter.
         *
         * @param filter The filter
         * @return this
         * @deprecated Use {@link #setFilter(Filter)}.
         */
        @Deprecated
        public B withFilter(final Filter filter) {
            return setFilter(filter);
        }

    }

    /**
     * May be null.
     */
    private volatile Filter filter;

    @PluginElement("Properties")
    private final Property[] propertyArray;

    protected AbstractFilterable() {
        this(null, Property.EMPTY_ARRAY);
    }

    protected AbstractFilterable(final Filter filter) {
        this(filter, Property.EMPTY_ARRAY);
    }

    /**
     * @since 2.11.2
     */
    protected AbstractFilterable(final Filter filter, final Property[] propertyArray) {
        this.filter = filter;
        this.propertyArray = propertyArray == null ? Property.EMPTY_ARRAY : propertyArray;
    }

    /**
     * Adds a filter.
     * @param filter The Filter to add.
     */
    @Override
    public synchronized void addFilter(final Filter filter) {
        if (filter == null) {
            return;
        }
        if (this.filter == null) {
            this.filter = filter;
        } else if (this.filter instanceof CompositeFilter) {
            this.filter = ((CompositeFilter) this.filter).addFilter(filter);
        } else {
            final Filter[] filters = new Filter[] {this.filter, filter};
            this.filter = CompositeFilter.createFilters(filters);
        }
    }

    /**
     * Returns the Filter.
     * @return the Filter or null.
     */
    @Override
    public Filter getFilter() {
        return filter;
    }

    /**
     * Determines if a Filter is present.
     * @return false if no Filter is present.
     */
    @Override
    public boolean hasFilter() {
        return filter != null;
    }

    /**
     * Determine if the LogEvent should be processed or ignored.
     * @param event The LogEvent.
     * @return true if the LogEvent should be processed.
     */
    @Override
    public boolean isFiltered(final LogEvent event) {
        return filter != null && filter.filter(event) == Filter.Result.DENY;
    }

    /**
     * Removes a Filter.
     * @param filter The Filter to remove.
     */
    @Override
    public synchronized void removeFilter(final Filter filter) {
        if (this.filter == null || filter == null) {
            return;
        }
        if (this.filter == filter || this.filter.equals(filter)) {
            this.filter = null;
        } else if (this.filter instanceof CompositeFilter) {
            CompositeFilter composite = (CompositeFilter) this.filter;
            composite = composite.removeFilter(filter);
            if (composite.size() > 1) {
                this.filter = composite;
            } else if (composite.size() == 1) {
                final Iterator<Filter> iter = composite.iterator();
                this.filter = iter.next();
            } else {
                this.filter = null;
            }
        }
    }

    /**
     * Make the Filter available for use.
     */
    @Override
    public void start() {
        this.setStarting();
        if (filter != null) {
            filter.start();
        }
        this.setStarted();
    }

    /**
     * Cleanup the Filter.
     */
    @Override
    public boolean stop(final long timeout, final TimeUnit timeUnit) {
        return stop(timeout, timeUnit, true);
    }

    /**
     * Cleanup the Filter.
     */
    protected boolean stop(final long timeout, final TimeUnit timeUnit, final boolean changeLifeCycleState) {
        if (changeLifeCycleState) {
            this.setStopping();
        }
        boolean stopped = true;
        if (filter != null) {
            if (filter instanceof LifeCycle2) {
                stopped = ((LifeCycle2) filter).stop(timeout, timeUnit);
            } else {
                filter.stop();
                stopped = true;
            }
        }
        if (changeLifeCycleState) {
            this.setStopped();
        }
        return stopped;
    }

    public Property[] getPropertyArray() {
        return propertyArray;
    }

}

⏎ org/apache/logging/log4j/core/filter/AbstractFilterable.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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