Source Code for Apache Log4j 1.2.17

Apache Log4j provides the interface that applications should code to and provides the adapter components required for implementers to create a logging implementation.

Bytecode (Java 1.4) for Apache Log4j is provided in a JAR file like log4j-1.2.17.jar.

Source Code files for Apache Log4j 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 1.2.17 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.

package org.apache.log4j.pattern;

import org.apache.log4j.spi.LoggingEvent;

import java.util.Iterator;
import java.util.Set;
import org.apache.log4j.helpers.*;

 * Able to handle the contents of the LoggingEvent's Property bundle and either
 * output the entire contents of the properties in a similar format to the
 * java.util.Hashtable.toString(), or to output the value of a specific key
 * within the property bundle
 * when this pattern converter has the option set.
 * @author Paul Smith
 * @author Ceki Gülcü
public final class PropertiesPatternConverter
  extends LoggingEventPatternConverter {
   * Name of property to output.
  private final String option;

   * Private constructor.
   * @param options options, may be null.
  private PropertiesPatternConverter(
    final String[] options) {
      ((options != null) && (options.length > 0))
      ? ("Property{" + options[0] + "}") : "Properties", "property");

    if ((options != null) && (options.length > 0)) {
      option = options[0];
    } else {
      option = null;

   * Obtains an instance of PropertiesPatternConverter.
   * @param options options, may be null or first element contains name of property to format.
   * @return instance of PropertiesPatternConverter.
  public static PropertiesPatternConverter newInstance(
    final String[] options) {
    return new PropertiesPatternConverter(options);

   * {@inheritDoc}
  public void format(final LoggingEvent event, final StringBuffer toAppendTo) {
    // if there is no additional options, we output every single
    // Key/Value pair for the MDC in a similar format to Hashtable.toString()
    if (option == null) {

      try {
        Set keySet = MDCKeySetExtractor.INSTANCE.getPropertyKeySet(event);
          if (keySet != null) {
            for (Iterator i = keySet.iterator(); i.hasNext();) {
                Object item =;
                Object val = event.getMDC(item.toString());
      } catch(Exception ex) {
              LogLog.error("Unexpected exception while extracting MDC keys", ex);

    } else {
      // otherwise they just want a single key output
      Object val = event.getMDC(option);

      if (val != null) {



Or download all of them as a single archive file:

File name: log4j-1.2.17-sources.jar
File size: 481200 bytes
Release date: 2012-05-06


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