org.openimaj.logger.LoggerUtils Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of core Show documentation
Core library functionality concerned with general programming problems rather than multimedia specific functionality. Includes I/O utilities, randomisation, hashing and type conversion.
The newest version!
/**
 * Copyright (c) 2011, The University of Southampton and the individual contributors.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 *   * 	Redistributions of source code must retain the above copyright notice,
 * 	this list of conditions and the following disclaimer.
 *
 *   *	Redistributions in binary form must reproduce the above copyright notice,
 * 	this list of conditions and the following disclaimer in the documentation
 * 	and/or other materials provided with the distribution.
 *
 *   *	Neither the name of the University of Southampton nor the names of its
 * 	contributors may be used to endorse or promote products derived from this
 * 	software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.openimaj.logger;

import org.apache.logging.log4j.Level;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.core.Filter.Result;
import org.apache.logging.log4j.core.appender.ConsoleAppender;
import org.apache.logging.log4j.core.filter.ThresholdFilter;
import org.apache.logging.log4j.core.layout.PatternLayout;

/**
 * Make using log4j slightly less awful
 *
 * @author Sina Samangooei ([email protected])
 *
 */
public class LoggerUtils {
	/**
	 * Prepare a console logger with a default layout. This allows {@link Logger}
	 * instances to be used while still being useful as the line to prepare logger
	 * can be removed and the default log4j.properties will be correctly listened
	 * to.
	 */
	public static void prepareConsoleLogger() {
		final String PATTERN = "%m\n";
		final PatternLayout layout = PatternLayout.newBuilder().withPattern(PATTERN).build();
		final ThresholdFilter filter = ThresholdFilter.createFilter(Level.DEBUG, Result.ACCEPT, Result.DENY);

		final ConsoleAppender console = ConsoleAppender.newBuilder().withName("default-consoleappender")
				.withLayout(layout).withFilter(filter).build();

		// add appender to any Logger (here is root)
		final Logger root = LogManager.getRootLogger();
		if (root instanceof org.apache.logging.log4j.core.Logger)
			((org.apache.logging.log4j.core.Logger) root).addAppender(console);
	}

	/**
	 * Debug message occationally
	 *
	 * @param logger
	 * @param message
	 * @param b
	 */
	public static void debug(Logger logger, String message, boolean b) {
		if (b) {
			logger.debug(message);
		}
	}

	/**
	 * Calls {@link #format(Logger, String, Level, Object...)} with level
	 * {@link Level#DEBUG}
	 *
	 * @param logger
	 * @param string
	 * @param obj
	 */
	public static void debugFormat(Logger logger, String string, Object... obj) {
		format(logger, string, Level.DEBUG, obj);
	}

	/**
	 * Checks the level, if acceptable calls
	 * {@link String#format(String, Object...)} at the appropriate level
	 *
	 * @param logger
	 * @param string
	 * @param debug
	 * @param obj
	 */
	public static void format(Logger logger, String string, Level debug, Object... obj) {
		final Level l = logger.getLevel();
		if (debug.isMoreSpecificThan(l)) {
			logger.log(debug, String.format(string, obj));
		}
	}
}