org.apache.logging.log4j.util.Constants Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.logging.log4j.util;
/**
* Log4j API Constants.
*
* @since 2.6.2
*/
public final class Constants {
/**
* {@code true} if we think we are running in a web container, based on the boolean value of system property
* "log4j2.is.webapp", or (if this system property is not set) whether the {@code javax.servlet.Servlet} class
* is present in the classpath.
*/
public static final boolean IS_WEB_APP = PropertiesUtil.getProperties().getBooleanProperty(
"log4j2.is.webapp", isClassAvailable("javax.servlet.Servlet"));
/**
* Kill switch for object pooling in ThreadLocals that enables much of the LOG4J2-1270 no-GC behaviour.
*
* {@code True} for non-{@link #IS_WEB_APP web apps}, disable by setting system property
* "log4j2.enable.threadlocals" to "false".
*/
public static final boolean ENABLE_THREADLOCALS = !IS_WEB_APP && PropertiesUtil.getProperties().getBooleanProperty(
"log4j2.enable.threadlocals", true);
/**
* Determines if a named Class can be loaded or not.
*
* @param className The class name.
* @return {@code true} if the class could be found or {@code false} otherwise.
*/
private static boolean isClassAvailable(final String className) {
try {
return LoaderUtil.loadClass(className) != null;
} catch (final Throwable e) {
return false;
}
}
/**
* Prevent class instantiation.
*/
private Constants() {
}
}