/*
 * Copyright 2002-2018 the original author or authors.
 *
 * Licensed 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.commons.logging;

A minimal incarnation of Apache Commons Logging's LogFactory API, providing just the common Log lookup methods. This is inspired by the JCL-over-SLF4J bridge and should be source as well as binary compatible with all common use of the Commons Logging API (in particular: with LogFactory.getLog(Class/String) field initializers). 
This implementation does not support Commons Logging's original provider detection. It rather only checks for the presence of the Log4j 2.x API and the SLF4J 1.7 API in the Spring Framework classpath, falling back to java.util.logging if none of the two is available. In that sense, it works as a replacement for the Log4j 2 Commons Logging bridge as well as the JCL-over-SLF4J bridge, both of which become irrelevant for Spring-based setups as a consequence (with no need for manual excludes of the standard Commons Logging API jar anymore either). Furthermore, for simple setups without an external logging provider, Spring does not require any extra jar on the classpath anymore since this embedded log factory automatically delegates to java.util.logging in such a scenario. 
Note that this Commons Logging variant is only meant to be used for
infrastructure logging purposes in the core framework and in extensions.
It also serves as a common bridge for third-party libraries using the
Commons Logging API, e.g. Apache HttpClient, Castor and HtmlUnit, bringing
them into the same consistent arrangement without any extra bridge jars.
For logging need in application code, prefer direct use of Log4j 2.x or SLF4J or java.util.logging. Simply put Log4j 2.x or Logback
(or another SLF4J provider) onto your classpath, without any extra bridges,
and let the framework auto-adapt to your choice.
Author:
Juergen Hoeller (for the spring-jcl variant)
Since:
5.0/**
 * A minimal incarnation of Apache Commons Logging's {@code LogFactory} API,
 * providing just the common {@link Log} lookup methods. This is inspired
 * by the JCL-over-SLF4J bridge and should be source as well as binary
 * compatible with all common use of the Commons Logging API (in particular:
 * with {@code LogFactory.getLog(Class/String)} field initializers).
 *
 * <p>This implementation does not support Commons Logging's original provider
 * detection. It rather only checks for the presence of the Log4j 2.x API
 * and the SLF4J 1.7 API in the Spring Framework classpath, falling back to
 * {@code java.util.logging} if none of the two is available. In that sense,
 * it works as a replacement for the Log4j 2 Commons Logging bridge as well as
 * the JCL-over-SLF4J bridge, both of which become irrelevant for Spring-based
 * setups as a consequence (with no need for manual excludes of the standard
 * Commons Logging API jar anymore either). Furthermore, for simple setups
 * without an external logging provider, Spring does not require any extra jar
 * on the classpath anymore since this embedded log factory automatically
 * delegates to {@code java.util.logging} in such a scenario.
 *
 * <p><b>Note that this Commons Logging variant is only meant to be used for
 * infrastructure logging purposes in the core framework and in extensions.</b>
 * It also serves as a common bridge for third-party libraries using the
 * Commons Logging API, e.g. Apache HttpClient, Castor and HtmlUnit, bringing
 * them into the same consistent arrangement without any extra bridge jars.
 *
 * <p><b>For logging need in application code, prefer direct use of Log4j 2.x
 * or SLF4J or {@code java.util.logging}.</b> Simply put Log4j 2.x or Logback
 * (or another SLF4J provider) onto your classpath, without any extra bridges,
 * and let the framework auto-adapt to your choice.
 *
 * @author Juergen Hoeller (for the {@code spring-jcl} variant)
 * @since 5.0
 */
public abstract class LogFactory {

	
Convenience method to return a named logger.
Params:
clazz – containing Class from which a log name will be derived/**
	 * Convenience method to return a named logger.
	 * @param clazz containing Class from which a log name will be derived
	 */
	public static Log getLog(Class<?> clazz) {
		return getLog(clazz.getName());
	}

	
Convenience method to return a named logger.
Params:
name – logical name of the Log instance to be returned/**
	 * Convenience method to return a named logger.
	 * @param name logical name of the <code>Log</code> instance to be returned
	 */
	public static Log getLog(String name) {
		return LogAdapter.createLog(name);
	}


	
This method only exists for compatibility with unusual Commons Logging API usage like e.g. LogFactory.getFactory().getInstance(Class/String). 
See Also:
getInstance(Class<?>)
getInstance(String)
Deprecated:
in favor of getLog(Class<?>)/getLog(String)/**
	 * This method only exists for compatibility with unusual Commons Logging API
	 * usage like e.g. {@code LogFactory.getFactory().getInstance(Class/String)}.
	 * @see #getInstance(Class)
	 * @see #getInstance(String)
	 * @deprecated in favor of {@link #getLog(Class)}/{@link #getLog(String)}
	 */
	@Deprecated
	public static LogFactory getFactory() {
		return new LogFactory() {};
	}

	
Convenience method to return a named logger.
This variant just dispatches straight to getLog(Class<?>). 
Params:
clazz – containing Class from which a log name will be derived
Deprecated:
in favor of getLog(Class<?>)/**
	 * Convenience method to return a named logger.
	 * <p>This variant just dispatches straight to {@link #getLog(Class)}.
	 * @param clazz containing Class from which a log name will be derived
	 * @deprecated in favor of {@link #getLog(Class)}
	 */
	@Deprecated
	public Log getInstance(Class<?> clazz) {
		return getLog(clazz);
	}

	
Convenience method to return a named logger.
This variant just dispatches straight to getLog(String). 
Params:
name – logical name of the Log instance to be returned
Deprecated:
in favor of getLog(String)/**
	 * Convenience method to return a named logger.
	 * <p>This variant just dispatches straight to {@link #getLog(String)}.
	 * @param name logical name of the <code>Log</code> instance to be returned
	 * @deprecated in favor of {@link #getLog(String)}
	 */
	@Deprecated
	public Log getInstance(String name) {
		return getLog(name);
	}

}