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.Layout;
import org.apache.log4j.bridge.LayoutWrapper;
import org.apache.log4j.config.Log4j1Configuration;
import org.apache.log4j.config.PropertiesConfiguration;
import org.apache.log4j.xml.XmlConfiguration;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.core.config.plugins.Plugin;
import org.apache.logging.log4j.core.config.plugins.PluginAliases;
import org.apache.logging.log4j.core.layout.PatternLayout;
import org.apache.logging.log4j.status.StatusLogger;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import java.util.Properties;

import static;
import static org.apache.log4j.xml.XmlConfiguration.PARAM_TAG;

 * Build a Pattern Layout
@Plugin(name = "org.apache.log4j.PatternLayout", category = CATEGORY)
public class PatternLayoutBuilder extends AbstractBuilder implements LayoutBuilder {

    private static final Logger LOGGER = StatusLogger.getLogger();
    private static final String PATTERN = "ConversionPattern";

    public PatternLayoutBuilder() {

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

    public Layout parseLayout(final Element layoutElement, final XmlConfiguration config) {
        NodeList params = layoutElement.getElementsByTagName("param");
        final int length = params.getLength();
        String pattern = null;
        for (int index = 0; index < length; ++ index) {
            Node currentNode = params.item(index);
            if (currentNode.getNodeType() == Node.ELEMENT_NODE) {
                Element currentElement = (Element) currentNode;
                if (currentElement.getTagName().equals(PARAM_TAG)) {
                    if (PATTERN.equalsIgnoreCase(currentElement.getAttribute("name"))) {
                        pattern = currentElement.getAttribute("value");
        return createLayout(pattern, config);

    public Layout parseLayout(final PropertiesConfiguration config) {
        String pattern = getProperty(PATTERN);
        return createLayout(pattern, config);

    private Layout createLayout(String pattern, final Log4j1Configuration config) {
        if (pattern == null) {
  "No pattern provided for pattern layout, using default pattern");
            pattern = PatternLayout.DEFAULT_CONVERSION_PATTERN;
        return new LayoutWrapper(PatternLayout.newBuilder()
                        // Log4j 2's %x (NDC) is not compatible with Log4j 1's
                        // %x
                        // Log4j 1: "foo bar baz"
                        // Log4j 2: "[foo, bar, baz]"
                        // Use %ndc to get the Log4j 1 format
                        .replace("%x", "%ndc")

                        // Log4j 2's %X (MDC) is not compatible with Log4j 1's
                        // %X
                        // Log4j 1: "{{foo,bar}{hoo,boo}}"
                        // Log4j 2: "{foo=bar,hoo=boo}"
                        // Use %properties to get the Log4j 1 format
                        .replace("%X", "%properties"))



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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