Apache Log4j 1.2 Bridge allows applications coded to use Log4j 1.2 API to use Log4j 2 instead.

Bytecode (Java 8) for Apache Log4j 1.2 Bridge is provided in a separate JAR file like log4j-1.2-api-2.14.1.jar.

Source Code files for Apache Log4j 1.2 Bridge 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 1.2 Bridge 2.14.1 below.

⏎ org/apache/log4j/builders/appender/FileAppenderBuilder.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.log4j.builders.appender;

import org.apache.log4j.Appender;
import org.apache.log4j.Layout;
import org.apache.log4j.bridge.AppenderWrapper;
import org.apache.log4j.bridge.LayoutAdapter;
import org.apache.log4j.bridge.LayoutWrapper;
import org.apache.log4j.builders.AbstractBuilder;
import org.apache.log4j.builders.BooleanHolder;
import org.apache.log4j.builders.Holder;
import org.apache.log4j.config.Log4j1Configuration;
import org.apache.log4j.config.PropertiesConfiguration;
import org.apache.log4j.spi.Filter;
import org.apache.log4j.xml.XmlConfiguration;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.core.appender.FileAppender;
import org.apache.logging.log4j.core.config.plugins.Plugin;
import org.apache.logging.log4j.status.StatusLogger;
import org.w3c.dom.Element;

import java.util.Properties;

import static org.apache.log4j.builders.BuilderManager.CATEGORY;
import static org.apache.log4j.config.Log4j1Configuration.THRESHOLD_PARAM;
import static org.apache.log4j.xml.XmlConfiguration.FILTER_TAG;
import static org.apache.log4j.xml.XmlConfiguration.LAYOUT_TAG;
import static org.apache.log4j.xml.XmlConfiguration.PARAM_TAG;
import static org.apache.log4j.xml.XmlConfiguration.forEachElement;
import static org.apache.log4j.xml.XmlConfiguration.NAME_ATTR;
import static org.apache.log4j.xml.XmlConfiguration.VALUE_ATTR;

/**
 * Build a File Appender
 */
@Plugin(name = "org.apache.log4j.FileAppender", category = CATEGORY)
public class FileAppenderBuilder extends AbstractBuilder implements AppenderBuilder {

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

    public FileAppenderBuilder() {
    }

    public FileAppenderBuilder(String prefix, Properties props) {
        super(prefix, props);
    }

    @Override
    public Appender parseAppender(Element appenderElement, XmlConfiguration config) {
        String name = appenderElement.getAttribute(NAME_ATTR);
        Holder<Layout> layout = new Holder<>();
        Holder<Filter> filter = new Holder<>();
        Holder<String> fileName = new Holder<>();
        Holder<String> level = new Holder<>();
        Holder<Boolean> immediateFlush = new BooleanHolder();
        Holder<Boolean> append = new BooleanHolder();
        Holder<Boolean> bufferedIo = new BooleanHolder();
        Holder<Integer> bufferSize = new Holder<>(8192);
        forEachElement(appenderElement.getChildNodes(), currentElement -> {
            switch (currentElement.getTagName()) {
                case LAYOUT_TAG:
                    layout.set(config.parseLayout(currentElement));
                    break;
                case FILTER_TAG:
                    filter.set(config.parseFilters(currentElement));
                    break;
                case PARAM_TAG: {
                    switch (currentElement.getAttribute(NAME_ATTR)) {
                        case FILE_PARAM:
                            fileName.set(currentElement.getAttribute(VALUE_ATTR));
                            break;
                        case APPEND_PARAM: {
                            String bool = currentElement.getAttribute(VALUE_ATTR);
                            if (bool != null) {
                                append.set(Boolean.parseBoolean(bool));
                            } else {
                                LOGGER.warn("No value provided for append parameter");
                            }
                            break;
                        }
                        case BUFFERED_IO_PARAM: {
                            String bool = currentElement.getAttribute(VALUE_ATTR);
                            if (bool != null) {
                                bufferedIo.set(Boolean.parseBoolean(bool));
                            } else {
                                LOGGER.warn("No value provided for bufferedIo parameter");
                            }
                            break;
                        }
                        case BUFFER_SIZE_PARAM: {
                            String size = currentElement.getAttribute(VALUE_ATTR);
                            if (size != null) {
                                bufferSize.set(Integer.parseInt(size));
                            } else {
                                LOGGER.warn("No value provide for bufferSize parameter");
                            }
                            break;
                        }
                        case THRESHOLD_PARAM: {
                            String value = currentElement.getAttribute(VALUE_ATTR);
                            if (value == null) {
                                LOGGER.warn("No value supplied for Threshold parameter, ignoring.");
                            } else {
                                level.set(value);
                            }
                            break;
                        }
                    }
                    break;
                }
            }
        });

        return createAppender(name, config, layout.get(), filter.get(), fileName.get(), level.get(),
                immediateFlush.get(), append.get(), bufferedIo.get(), bufferSize.get());
    }


    @Override
    public Appender parseAppender(final String name, final String appenderPrefix, final String layoutPrefix,
            final String filterPrefix, final Properties props, final PropertiesConfiguration configuration) {
        Layout layout = configuration.parseLayout(layoutPrefix, name, props);
        Filter filter = configuration.parseAppenderFilters(props, filterPrefix, name);
        String level = getProperty(THRESHOLD_PARAM);
        String fileName = getProperty(FILE_PARAM);
        boolean append = getBooleanProperty(APPEND_PARAM);
        boolean immediateFlush = false;
        boolean bufferedIo = getBooleanProperty(BUFFERED_IO_PARAM);
        int bufferSize = Integer.parseInt(getProperty(BUFFER_SIZE_PARAM, "8192"));
        return createAppender(name, configuration, layout, filter, fileName, level, immediateFlush,
                append, bufferedIo, bufferSize);
    }

    private Appender createAppender(final String name, final Log4j1Configuration configuration, final Layout layout,
            final Filter filter, final String fileName, String level, boolean immediateFlush, final boolean append,
            final boolean bufferedIo, final int bufferSize) {
        org.apache.logging.log4j.core.Layout<?> fileLayout = null;
        if (bufferedIo) {
            immediateFlush = true;
        }
        if (layout instanceof LayoutWrapper) {
            fileLayout = ((LayoutWrapper) layout).getLayout();
        } else if (layout != null) {
            fileLayout = new LayoutAdapter(layout);
        }
        org.apache.logging.log4j.core.Filter fileFilter = buildFilters(level, filter);
        if (fileName == null) {
            LOGGER.warn("Unable to create File Appender, no file name provided");
            return null;
        }
        return new AppenderWrapper(FileAppender.newBuilder()
                .setName(name)
                .setConfiguration(configuration)
                .setLayout(fileLayout)
                .setFilter(fileFilter)
                .withFileName(fileName)
                .withImmediateFlush(immediateFlush)
                .withAppend(append)
                .withBufferedIo(bufferedIo)
                .withBufferSize(bufferSize)
                .build());
    }
}

⏎ org/apache/log4j/builders/appender/FileAppenderBuilder.java

 

⇒ Source Code for Apache Log4j JMX GUI

⇐ Source Code for Apache Log4j Flume Appender

⇑ Downloading and Reviewing Apache Log4j Packages

⇑⇑ FAQ for Apache Log4j