A java class that shows how to format a Logger.class

001-Logger-Formatter.java

package net.wynsolutions.slackapi.log;

import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.logging.Formatter;
import java.util.logging.Handler;
import java.util.logging.LogRecord;

/**
 * Copyright (C) 2017 Sw4p
 *
 * This program is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program. If not, see <http://www.gnu.org/licenses/>.
 * 
 * @author Sw4p
 *
 */
public class LoggerFormatter extends Formatter{

	// Create a DateFormat to format the logger timestamp.
	private static final DateFormat df = new SimpleDateFormat("dd/MM/yyyy hh:mm:ss.SSS");

	public String format(LogRecord record) {
		StringBuilder builder = new StringBuilder(1000);
		builder.append("[").append(df.format(new Date(record.getMillis()))).append("] ");
		builder.append("[").append(record.getLevel()).append("] ");
		builder.append(formatMessage(record));
		builder.append("\n");
		return builder.toString();
	}

	public String getHead(Handler h) {
		return super.getHead(h);
	}

	public String getTail(Handler h) {
		return super.getTail(h);
	}

}

002-Logger-Set-Formatter.java

package net.wynsolutions.slackapi;

import java.util.logging.ConsoleHandler;
import java.util.logging.Logger;

import net.wynsolutions.slackapi.log.LoggerFormatter;

/**
 * Copyright (C) 2017  Sw4p
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * @author Sw4p
 *
 */
public class Main {
  
  public static void main(String[] args){
    Logger logger = Logger.getLogger(Main.class.toString());
    logger.setUseParentHandlers(false);
    
    ConsoleHandler handler = new ConsoleHandler();
    handler.setFormatter(new LoggerFormatter());
    logger.addHandler(handler);
  }
  
}