001/* 002 * (C) Copyright 2017 Nuxeo (http://nuxeo.com/) and others. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 * 016 * Contributors: 017 * Florent Guillaume 018 */ 019package org.nuxeo.common.logging; 020 021import java.net.URL; 022 023/** 024 * Helper for log4j. 025 * 026 * @since 9.2 027 */ 028public class Log4JHelper { 029 030 // utility class 031 private Log4JHelper() { 032 } 033 034 /** 035 * Calls log4j's DOMConfigurator.configureAndWatch method, if available, to automatically watch and reload the 036 * configuration file if needed. 037 * 038 * @param delay 039 * the delay (in milliseconds) 040 * @return {@code true} if log4j is available and the call succeeded 041 */ 042 public static Log4jWatchdogHandle configureAndWatch(long delay) { 043 ClassLoader contextClassLoader = Thread.currentThread().getContextClassLoader(); 044 URL url = contextClassLoader.getResource("log4j.xml"); 045 if (url == null) { 046 return null; 047 } 048 try { 049 return Log4jWatchdog.watch(url.getFile(), delay); 050 } catch (LinkageError cause) { 051 return null; 052 } 053 } 054 055}