Source Code for Apache Log4j 1.2 Bridge

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 and source package like 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.



 * 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
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * See the license for the specific language governing permissions and
 * limitations under the license.

import org.apache.log4j.Appender;
import org.apache.log4j.bridge.AppenderWrapper;
import org.apache.log4j.bridge.RewritePolicyAdapter;
import org.apache.log4j.bridge.RewritePolicyWrapper;
import org.apache.log4j.config.Log4j1Configuration;
import org.apache.log4j.config.PropertiesConfiguration;
import org.apache.log4j.helpers.OptionConverter;
import org.apache.log4j.rewrite.RewritePolicy;
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.rewrite.RewriteAppender;
import org.apache.logging.log4j.core.config.AppenderRef;
import org.apache.logging.log4j.core.config.plugins.Plugin;
import org.apache.logging.log4j.status.StatusLogger;
import org.w3c.dom.Element;

import java.util.ArrayList;
import java.util.List;
import java.util.Properties;

import static;
import static org.apache.log4j.config.Log4j1Configuration.APPENDER_REF_TAG;
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.NAME_ATTR;
import static org.apache.log4j.xml.XmlConfiguration.PARAM_TAG;
import static org.apache.log4j.xml.XmlConfiguration.VALUE_ATTR;
import static org.apache.log4j.xml.XmlConfiguration.forEachElement;

 * Build an Asynch Appender
@Plugin(name = "org.apache.log4j.rewrite.RewriteAppender", category = CATEGORY)
public class RewriteAppenderBuilder extends AbstractBuilder implements AppenderBuilder {

    private static final Logger LOGGER = StatusLogger.getLogger();
    private static final String REWRITE_POLICY_TAG = "rewritePolicy";

    public RewriteAppenderBuilder() {

    public RewriteAppenderBuilder(String prefix, Properties props) {
        super(prefix, props);

    public Appender parseAppender(final Element appenderElement, final XmlConfiguration config) {
        String name = appenderElement.getAttribute(NAME_ATTR);
        Holder<List<String>> appenderRefs = new Holder<>(new ArrayList<>());
        Holder<RewritePolicy> rewritePolicyHolder = new Holder<>();
        Holder<String> level = new Holder<>();
        Holder<Filter> filter = new Holder<>();
        forEachElement(appenderElement.getChildNodes(), currentElement -> {
            switch (currentElement.getTagName()) {
                case APPENDER_REF_TAG:
                    Appender appender = config.findAppenderByReference(currentElement);
                    if (appender != null) {
                case REWRITE_POLICY_TAG: {
                    RewritePolicy policy = config.parseRewritePolicy(currentElement);
                    if (policy != null) {
                case FILTER_TAG: {
                case PARAM_TAG: {
                    if (currentElement.getAttribute(NAME_ATTR).equalsIgnoreCase(THRESHOLD_PARAM)) {
                        String value = currentElement.getAttribute(VALUE_ATTR);
                        if (value == null) {
                            LOGGER.warn("No value supplied for Threshold parameter, ignoring.");
                        } else {
        return createAppender(name, level.get(), appenderRefs.get().toArray(new String[0]), rewritePolicyHolder.get(),
                filter.get(), config);

    public Appender parseAppender(final String name, final String appenderPrefix, final String layoutPrefix,
            final String filterPrefix, final Properties props, final PropertiesConfiguration configuration) {
        String appenderRef = getProperty(APPENDER_REF_TAG);
        Filter filter = configuration.parseAppenderFilters(props, filterPrefix, name);
        String policyPrefix = appenderPrefix + ".rewritePolicy";
        String className = getProperty(policyPrefix);
        RewritePolicy policy = configuration.getBuilderManager().parseRewritePolicy(className, policyPrefix,
                props, configuration);
        String level = getProperty(THRESHOLD_PARAM);
        if (appenderRef == null) {
            LOGGER.warn("No appender references configured for AsyncAppender {}", name);
            return null;
        Appender appender = configuration.parseAppender(props, appenderRef);
        if (appender == null) {
            LOGGER.warn("Cannot locate Appender {}", appenderRef);
            return null;
        return createAppender(name, level, new String[] {appenderRef}, policy, filter, configuration);

    private <T extends Log4j1Configuration> Appender createAppender(String name, String level,
            String[] appenderRefs, RewritePolicy policy, Filter filter, T configuration) {
        org.apache.logging.log4j.Level logLevel = OptionConverter.convertLevel(level,
        AppenderRef[] refs = new AppenderRef[appenderRefs.length];
        int index = 0;
        for (String appenderRef : appenderRefs) {
            refs[index++] = AppenderRef.createAppenderRef(appenderRef, logLevel, null);
        org.apache.logging.log4j.core.Filter rewriteFilter = buildFilters(level, filter);
        org.apache.logging.log4j.core.appender.rewrite.RewritePolicy rewritePolicy;
        if (policy instanceof RewritePolicyWrapper) {
            rewritePolicy = ((RewritePolicyWrapper) policy).getPolicy();
        } else {
            rewritePolicy = new RewritePolicyAdapter(policy);
        return new AppenderWrapper(RewriteAppender.createAppender(name, "true", refs, configuration,
                rewritePolicy, rewriteFilter));



Or download all of them as a single archive file:

File name: log4j-1.2-api-2.14.1-sources.jar
File size: 168047 bytes
Release date: 2021-03-06


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