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 log4j-1.2.17.zip and source package like log4j-1.2.17-sources.zip. You can download them at Apache Log4j Website.

You can also browse Source Code files for Apache Log4j 1.2.17 below.

⏎ org/apache/log4j/pattern/LevelPatternConverter.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.pattern;

import org.apache.log4j.Level;
import org.apache.log4j.spi.LoggingEvent;


/**
 * Return the event's level in a StringBuffer.
 *
 * @author Ceki Gülcü
 */
public final class LevelPatternConverter extends LoggingEventPatternConverter {

  /**
   *   Integer severity for Level.TRACE.
   */
  private static final int TRACE_INT = 5000;
  /**
   * Singleton.
   */
  private static final LevelPatternConverter INSTANCE =
    new LevelPatternConverter();

  /**
   * Private constructor.
   */
  private LevelPatternConverter() {
    super("Level", "level");
  }

  /**
   * Obtains an instance of pattern converter.
   * @param options options, may be null.
   * @return instance of pattern converter.
   */
  public static LevelPatternConverter newInstance(
    final String[] options) {
    return INSTANCE;
  }

  /**
   * {@inheritDoc}
   */
  public void format(final LoggingEvent event, final StringBuffer output) {
    output.append(event.getLevel().toString());
  }

  /**
   * {@inheritDoc}
   */
  public String getStyleClass(Object e) {
    if (e instanceof LoggingEvent) {
      int lint = ((LoggingEvent) e).getLevel().toInt();

      switch (lint) {
      case TRACE_INT:
        return "level trace";

      case Level.DEBUG_INT:
        return "level debug";

      case Level.INFO_INT:
        return "level info";

      case Level.WARN_INT:
        return "level warn";

      case Level.ERROR_INT:
        return "level error";

      case Level.FATAL_INT:
        return "level fatal";

      default:
        return "level " + ((LoggingEvent) e).getLevel().toString();
      }
    }

    return "level";
  }
}

⏎ org/apache/log4j/pattern/LevelPatternConverter.java

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
Download 

⇒ Download and Install apache-log4j-1.2.15.zip

⇐ Download and Install log4j-1.2.17.zip

⇑ Downloading Apache Log4j 1.x JAR Packages

⇑⇑ FAQ for Apache Log4j