http://www.eclipse.org/platform: OSGi System Bundle %systemBundle (Eclipse Foundation) 
/*
 * Copyright (c) OSGi Alliance (2016, 2018). All Rights Reserved.
 * 
 * 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.osgi.service.log;

import org.osgi.annotation.versioning.ProviderType;
import org.osgi.framework.Bundle;


Logger Factory service for logging information.

 Provides methods for bundles to obtain named Loggers that can be used to write messages to the log. 
 Logger names should be in the form of a fully qualified Java class names with segments separated by full stop ('.' \u002E). For example: 
com.foo.Bar

 Logger names exist in a hierarchy. A logger name is said to be an ancestor of another logger name if the logger name followed by a full stop ('.' \u002E) is a prefix of the descendant logger name. The root logger name is the top ancestor of the logger name hierarchy. For example: 
com.foo.Bar
com.foo
com
ROOT



Author:$Id: 756540e45fd79c3343529926f9cb2114ff53a101 $
@ThreadSafe
Since:1.4
/**
 * Logger Factory service for logging information.
 * <p>
 * Provides methods for bundles to obtain named {@link Logger}s that can be used
 * to write messages to the log.
 * <p>
 * Logger names should be in the form of a fully qualified Java class names with
 * segments separated by full stop ({@code '.'} &#92;u002E). For example:
 * 
 * <pre>
 * com.foo.Bar
 * </pre>
 * 
 * Logger names exist in a hierarchy. A logger name is said to be an ancestor of
 * another logger name if the logger name followed by a full stop ({@code '.'}
 * &#92;u002E) is a prefix of the descendant logger name. The
 * {@link Logger#ROOT_LOGGER_NAME root logger name} is the top ancestor of the
 * logger name hierarchy. For example:
 * 
 * <pre>
 * com.foo.Bar
 * com.foo
 * com
 * ROOT
 * </pre>
 * 
 * @ThreadSafe
 * @since 1.4
 * @author $Id: 756540e45fd79c3343529926f9cb2114ff53a101 $
 */
@ProviderType
public interface LoggerFactory {

	
Return the Logger named with the specified name. 
Params:
  • name – The name to use for the logger name. Must not be null.
Returns:The Logger named with the specified name. If the name parameter is equal to Logger.ROOT_LOGGER_NAME, then the root logger is returned.
/**
	 * Return the {@link Logger} named with the specified name.
	 * 
	 * @param name The name to use for the logger name. Must not be
	 *            {@code null}.
	 * @return The {@link Logger} named with the specified name. If the name
	 *         parameter is equal to {@link Logger#ROOT_LOGGER_NAME}, then the
	 *         root logger is returned.
	 */
	Logger getLogger(String name);

	
Return the Logger named with the specified class. 
Params:
  • clazz – The class to use for the logger name. Must not be null.
Returns:The Logger named with the name of the specified class.
/**
	 * Return the {@link Logger} named with the specified class.
	 * 
	 * @param clazz The class to use for the logger name. Must not be
	 *            {@code null}.
	 * @return The {@link Logger} named with the name of the specified class.
	 */
	Logger getLogger(Class< ? > clazz);

	
Return the Logger of the specified type named with the specified name. 
Params:
  • name – The name to use for the logger name. Must not be null.
  • loggerType – The type of Logger. Can be Logger or FormatterLogger.
Type parameters:
  • <L> – The Logger type.
Throws:
Returns:The Logger or FormatterLogger named with the specified name. If the name parameter is equal to Logger.ROOT_LOGGER_NAME, then the root logger is returned.
/**
	 * Return the {@link Logger} of the specified type named with the specified
	 * name.
	 * 
	 * @param <L> The Logger type.
	 * @param name The name to use for the logger name. Must not be
	 *            {@code null}.
	 * @param loggerType The type of Logger. Can be {@link Logger} or
	 *            {@link FormatterLogger}.
	 * @return The {@link Logger} or {@link FormatterLogger} named with the
	 *         specified name. If the name parameter is equal to
	 *         {@link Logger#ROOT_LOGGER_NAME}, then the root logger is
	 *         returned.
	 * @throws IllegalArgumentException If the specified type is not a supported
	 *             Logger type.
	 */
	<L extends Logger> L getLogger(String name, Class<L> loggerType);

	
Return the Logger of the specified type named with the specified class. 
Params:
  • clazz – The class to use for the logger name. Must not be null.
  • loggerType – The type of Logger. Can be Logger or FormatterLogger. Must not be null.
Type parameters:
  • <L> – A Logger type.
Throws:
Returns:The Logger or FormatterLogger named with the name of the specified class.
/**
	 * Return the {@link Logger} of the specified type named with the specified
	 * class.
	 * 
	 * @param <L> A Logger type.
	 * @param clazz The class to use for the logger name. Must not be
	 *            {@code null}.
	 * @param loggerType The type of Logger. Can be {@link Logger} or
	 *            {@link FormatterLogger}. Must not be {@code null}.
	 * @return The {@link Logger} or {@link FormatterLogger} named with the name
	 *         of the specified class.
	 * @throws IllegalArgumentException If the specified type is not a supported
	 *             Logger type.
	 */
	<L extends Logger> L getLogger(Class< ? > clazz, Class<L> loggerType);

	
Return the Logger of the specified type named with the specified name for the specified bundle. 
 This method is not normally used. The other getLogger methods return a Logger associated with the bundle used to obtain this Logger Factory service. This method is used to obtain a Logger for the specified bundle which may be useful to code which is logging on behalf of another bundle. 
Params:
  • bundle – The bundle associated with the Logger. Must not be null.
  • name – The name to use for the logger name. Must not be null.
  • loggerType – The type of Logger. Can be Logger or FormatterLogger. Must not be null.
Type parameters:
  • <L> – The Logger type.
Throws:
  • IllegalArgumentException – If the specified type is not a supported
            Logger type or the specified Bundle is not a resolved bundle.
Returns:The Logger or FormatterLogger named with the specified name for the specified bundle. If the name parameter is equal to Logger.ROOT_LOGGER_NAME, then the root logger is returned.
/**
	 * Return the {@link Logger} of the specified type named with the specified
	 * name for the specified bundle.
	 * <p>
	 * This method is not normally used. The other {@code getLogger} methods
	 * return a {@link Logger} associated with the bundle used to obtain this
	 * Logger Factory service. This method is used to obtain a {@link Logger}
	 * for the specified bundle which may be useful to code which is logging on
	 * behalf of another bundle.
	 * 
	 * @param <L> The Logger type.
	 * @param bundle The bundle associated with the Logger. Must not be
	 *            {@code null}.
	 * @param name The name to use for the logger name. Must not be
	 *            {@code null}.
	 * @param loggerType The type of Logger. Can be {@link Logger} or
	 *            {@link FormatterLogger}. Must not be {@code null}.
	 * @return The {@link Logger} or {@link FormatterLogger} named with the
	 *         specified name for the specified bundle. If the name parameter is
	 *         equal to {@link Logger#ROOT_LOGGER_NAME}, then the root logger is
	 *         returned.
	 * @throws IllegalArgumentException If the specified type is not a supported
	 *             Logger type or the specified Bundle is not a resolved bundle.
	 */
	<L extends Logger> L getLogger(Bundle bundle, String name,
			Class<L> loggerType);
}