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/rolling/DirectWriteRolloverStrategy.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.rolling;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.SortedMap;
import java.util.concurrent.TimeUnit;
import java.util.zip.Deflater;

import org.apache.logging.log4j.core.Core;
import org.apache.logging.log4j.core.appender.rolling.action.Action;
import org.apache.logging.log4j.core.appender.rolling.action.CompositeAction;
import org.apache.logging.log4j.core.appender.rolling.action.FileRenameAction;
import org.apache.logging.log4j.core.appender.rolling.action.PathCondition;
import org.apache.logging.log4j.core.appender.rolling.action.PosixViewAttributeAction;
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.PluginAttribute;
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.PluginFactory;
import org.apache.logging.log4j.core.lookup.StrSubstitutor;
import org.apache.logging.log4j.core.util.Integers;

/**
 * When rolling over, <code>DirectWriteRolloverStrategy</code> writes directly to the file as resolved by the file
 * pattern. Files will be renamed files according to an algorithm as described below.
 *
 * <p>
 * The DirectWriteRolloverStrategy uses similar logic as DefaultRolloverStrategy to determine the file name based
 * on the file pattern, however the DirectWriteRolloverStrategy writes directly to a file and does not rename it
 * during rollover, except if it is compressed, in which case it will add the appropriate file extension.
 * </p>
 *
 * @since 2.8
 */
@Plugin(name = "DirectWriteRolloverStrategy", category = Core.CATEGORY_NAME, printObject = true)
public class DirectWriteRolloverStrategy extends AbstractRolloverStrategy implements DirectFileRolloverStrategy {

    private static final int DEFAULT_MAX_FILES = 7;

    /**
     * Builds DirectWriteRolloverStrategy instances.
     */
    public static class Builder implements org.apache.logging.log4j.core.util.Builder<DirectWriteRolloverStrategy> {
        @PluginBuilderAttribute("maxFiles")
        private String maxFiles;

        @PluginBuilderAttribute("compressionLevel")
        private String compressionLevelStr;

        @PluginElement("Actions")
        private Action[] customActions;

        @PluginBuilderAttribute(value = "stopCustomActionsOnError")
        private boolean stopCustomActionsOnError = true;

        @PluginBuilderAttribute(value = "tempCompressedFilePattern")
        private String tempCompressedFilePattern;

        @PluginConfiguration
        private Configuration config;

        @Override
        public DirectWriteRolloverStrategy build() {
            int maxIndex = Integer.MAX_VALUE;
            if (maxFiles != null) {
                maxIndex = Integer.parseInt(maxFiles);
                if (maxIndex < 0) {
                    maxIndex = Integer.MAX_VALUE;
                } else if (maxIndex < 2) {
                    LOGGER.error("Maximum files too small. Limited to " + DEFAULT_MAX_FILES);
                    maxIndex = DEFAULT_MAX_FILES;
                }
            }
            final int compressionLevel = Integers.parseInt(compressionLevelStr, Deflater.DEFAULT_COMPRESSION);
            return new DirectWriteRolloverStrategy(maxIndex, compressionLevel, config.getStrSubstitutor(),
                    customActions, stopCustomActionsOnError, tempCompressedFilePattern);
        }

        public String getMaxFiles() {
            return maxFiles;
        }

        /**
         * Defines the maximum number of files to keep.
         *
         * @param maxFiles The maximum number of files that match the date portion of the pattern to keep.
         * @return This builder for chaining convenience
         */
        public Builder withMaxFiles(final String maxFiles) {
            this.maxFiles = maxFiles;
            return this;
        }

        public String getCompressionLevelStr() {
            return compressionLevelStr;
        }

        /**
         * Defines compression level.
         *
         * @param compressionLevelStr The compression level, 0 (less) through 9 (more); applies only to ZIP files.
         * @return This builder for chaining convenience
         */
        public Builder withCompressionLevelStr(final String compressionLevelStr) {
            this.compressionLevelStr = compressionLevelStr;
            return this;
        }

        public Action[] getCustomActions() {
            return customActions;
        }

        /**
         * Defines custom actions.
         *
         * @param customActions custom actions to perform asynchronously after rollover
         * @return This builder for chaining convenience
         */
        public Builder withCustomActions(final Action[] customActions) {
            this.customActions = customActions;
            return this;
        }

        public boolean isStopCustomActionsOnError() {
            return stopCustomActionsOnError;
        }

        /**
         * Defines whether to stop executing asynchronous actions if an error occurs.
         *
         * @param stopCustomActionsOnError whether to stop executing asynchronous actions if an error occurs
         * @return This builder for chaining convenience
         */
        public Builder withStopCustomActionsOnError(final boolean stopCustomActionsOnError) {
            this.stopCustomActionsOnError = stopCustomActionsOnError;
            return this;
        }

        public String getTempCompressedFilePattern() {
            return tempCompressedFilePattern;
        }

        /**
         * Defines temporary compression file pattern.
         *
         * @param tempCompressedFilePattern File pattern of the working file pattern used during compression, if null no temporary file are used
         * @return This builder for chaining convenience
         */
        public Builder withTempCompressedFilePattern(final String tempCompressedFilePattern) {
            this.tempCompressedFilePattern = tempCompressedFilePattern;
            return this;
        }

        public Configuration getConfig() {
            return config;
        }

        /**
         * Defines configuration.
         *
         * @param config The Configuration.
         * @return This builder for chaining convenience
         */
        public Builder withConfig(final Configuration config) {
            this.config = config;
            return this;
        }
    }

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

    /**
     * Creates the DirectWriteRolloverStrategy.
     *
     * @param maxFiles The maximum number of files that match the date portion of the pattern to keep.
     * @param compressionLevelStr The compression level, 0 (less) through 9 (more); applies only to ZIP files.
     * @param customActions custom actions to perform asynchronously after rollover
     * @param stopCustomActionsOnError whether to stop executing asynchronous actions if an error occurs
     * @param config The Configuration.
     * @return A DirectWriteRolloverStrategy.
     * @deprecated Since 2.9 Usage of Builder API is preferable
     */
    @Deprecated
    @PluginFactory
    public static DirectWriteRolloverStrategy createStrategy(
            // @formatter:off
            @PluginAttribute("maxFiles") final String maxFiles,
            @PluginAttribute("compressionLevel") final String compressionLevelStr,
            @PluginElement("Actions") final Action[] customActions,
            @PluginAttribute(value = "stopCustomActionsOnError", defaultBoolean = true)
                    final boolean stopCustomActionsOnError,
            @PluginConfiguration final Configuration config) {
            return newBuilder().withMaxFiles(maxFiles)
                    .withCompressionLevelStr(compressionLevelStr)
                    .withCustomActions(customActions)
                    .withStopCustomActionsOnError(stopCustomActionsOnError)
                    .withConfig(config)
                    .build();
            // @formatter:on
    }

    /**
     * Index for most recent log file.
     */
    private final int maxFiles;
    private final int compressionLevel;
    private final List<Action> customActions;
    private final boolean stopCustomActionsOnError;
    private volatile String currentFileName;
    private int nextIndex = -1;
    private final PatternProcessor tempCompressedFilePattern;
    private volatile boolean usePrevTime = false;

    /**
     * Constructs a new instance.
     *
     * @param maxFiles The maximum number of files that match the date portion of the pattern to keep.
     * @param customActions custom actions to perform asynchronously after rollover
     * @param stopCustomActionsOnError whether to stop executing asynchronous actions if an error occurs
     * @deprecated Since 2.9 Added tempCompressedFilePatternString parameter
     */
    @Deprecated
    protected DirectWriteRolloverStrategy(final int maxFiles, final int compressionLevel,
                                          final StrSubstitutor strSubstitutor, final Action[] customActions,
                                          final boolean stopCustomActionsOnError) {
        this(maxFiles, compressionLevel, strSubstitutor, customActions, stopCustomActionsOnError, null);
    }

    /**
     * Constructs a new instance.
     *
     * @param maxFiles The maximum number of files that match the date portion of the pattern to keep.
     * @param customActions custom actions to perform asynchronously after rollover
     * @param stopCustomActionsOnError whether to stop executing asynchronous actions if an error occurs
     * @param tempCompressedFilePatternString File pattern of the working file
     *                                     used during compression, if null no temporary file are used
     */
    protected DirectWriteRolloverStrategy(final int maxFiles, final int compressionLevel,
                                          final StrSubstitutor strSubstitutor, final Action[] customActions,
                                          final boolean stopCustomActionsOnError, final String tempCompressedFilePatternString) {
        super(strSubstitutor);
        this.maxFiles = maxFiles;
        this.compressionLevel = compressionLevel;
        this.stopCustomActionsOnError = stopCustomActionsOnError;
        this.customActions = customActions == null ? Collections.<Action> emptyList() : Arrays.asList(customActions);
        this.tempCompressedFilePattern =
                tempCompressedFilePatternString != null ? new PatternProcessor(tempCompressedFilePatternString) : null;
    }

    public int getCompressionLevel() {
        return this.compressionLevel;
    }

    public List<Action> getCustomActions() {
        return customActions;
    }

    public int getMaxFiles() {
        return this.maxFiles;
    }

    public boolean isStopCustomActionsOnError() {
        return stopCustomActionsOnError;
    }

    public PatternProcessor getTempCompressedFilePattern() {
        return tempCompressedFilePattern;
    }

    private int purge(final RollingFileManager manager) {
        final SortedMap<Integer, Path> eligibleFiles = getEligibleFiles(manager);
        LOGGER.debug("Found {} eligible files, max is  {}", eligibleFiles.size(), maxFiles);
        while (eligibleFiles.size() >= maxFiles) {
            try {
                final Integer key = eligibleFiles.firstKey();
                Files.delete(eligibleFiles.get(key));
                eligibleFiles.remove(key);
            } catch (final IOException ioe) {
                LOGGER.error("Unable to delete {}", eligibleFiles.firstKey(), ioe);
                break;
            }
        }
        return eligibleFiles.size() > 0 ? eligibleFiles.lastKey() : 1;
    }

    @Override
    public String getCurrentFileName(final RollingFileManager manager) {
        if (currentFileName == null) {
            final SortedMap<Integer, Path> eligibleFiles = getEligibleFiles(manager);
            final int fileIndex = eligibleFiles.size() > 0 ? (nextIndex > 0 ? nextIndex : eligibleFiles.size()) : 1;
            final StringBuilder buf = new StringBuilder(255);
            manager.getPatternProcessor().formatFileName(strSubstitutor, buf, true, fileIndex);
            final int suffixLength = suffixLength(buf.toString());
            final String name = suffixLength > 0 ? buf.substring(0, buf.length() - suffixLength) : buf.toString();
            currentFileName = name;
        }
        return currentFileName;
    }

    @Override
    public void clearCurrentFileName() {
        currentFileName = null;
    }

    /**
     * Performs the rollover.
     *
     * @param manager The RollingFileManager name for current active log file.
     * @return A RolloverDescription.
     * @throws SecurityException if an error occurs.
     */
    @Override
    public RolloverDescription rollover(final RollingFileManager manager) throws SecurityException {
        LOGGER.debug("Rolling " + currentFileName);
        if (maxFiles < 0) {
            return null;
        }
        final long startNanos = System.nanoTime();
        final int fileIndex = purge(manager);
        if (LOGGER.isTraceEnabled()) {
            final double durationMillis = TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - startNanos);
            LOGGER.trace("DirectWriteRolloverStrategy.purge() took {} milliseconds", durationMillis);
        }
        Action compressAction = null;
        final String sourceName = getCurrentFileName(manager);
        String compressedName = sourceName;
        currentFileName = null;
        nextIndex = fileIndex + 1;
        final FileExtension fileExtension = manager.getFileExtension();
        if (fileExtension != null) {
            compressedName += fileExtension.getExtension();
            if (tempCompressedFilePattern != null) {
                final StringBuilder buf = new StringBuilder();
                tempCompressedFilePattern.formatFileName(strSubstitutor, buf, fileIndex);
                final String tmpCompressedName = buf.toString();
                final File tmpCompressedNameFile = new File(tmpCompressedName);
                final File parentFile = tmpCompressedNameFile.getParentFile();
                if (parentFile != null) {
                    parentFile.mkdirs();
                }
                compressAction = new CompositeAction(
                        Arrays.asList(fileExtension.createCompressAction(sourceName, tmpCompressedName,
                                true, compressionLevel),
                                new FileRenameAction(tmpCompressedNameFile,
                                        new File(compressedName), true)),
                        true);
            } else {
                compressAction = fileExtension.createCompressAction(sourceName, compressedName,
                      true, compressionLevel);
            }
        }

        if (compressAction != null && manager.isAttributeViewEnabled()) {
            // Propagate posix attribute view to compressed file
            // @formatter:off
            final Action posixAttributeViewAction = PosixViewAttributeAction.newBuilder()
                                                    .withBasePath(compressedName)
                                                    .withFollowLinks(false)
                                                    .withMaxDepth(1)
                                                    .withPathConditions(new PathCondition[0])
                                                    .withSubst(getStrSubstitutor())
                                                    .withFilePermissions(manager.getFilePermissions())
                                                    .withFileOwner(manager.getFileOwner())
                                                    .withFileGroup(manager.getFileGroup())
                                                    .build();
            // @formatter:on
            compressAction = new CompositeAction(Arrays.asList(compressAction, posixAttributeViewAction), false);
        }

        final Action asyncAction = merge(compressAction, customActions, stopCustomActionsOnError);
        return new RolloverDescriptionImpl(sourceName, false, null, asyncAction);
    }

    @Override
    public String toString() {
        return "DirectWriteRolloverStrategy(maxFiles=" + maxFiles + ')';
    }

}

⏎ org/apache/logging/log4j/core/appender/rolling/DirectWriteRolloverStrategy.java

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