Here you can find the source of warn(Logger log, Object... args)
public static void warn(Logger log, Object... args)
//package com.java2s; /*//from ww w . j a v a 2s. co m * Copyright (C) 2012 McEvoy Software Ltd * * 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/>. * */ import org.slf4j.Logger; public class Main { public static void warn(Logger log, Object... args) { if (log.isWarnEnabled()) { StringBuilder sb = new StringBuilder(); for (Object o : args) { sb.append(o).append(", "); } log.warn(sb.toString()); } } }