ContextInitializer.java
/*
* Logback: the reliable, generic, fast and flexible logging framework.
* Copyright (C) 1999-2026, QOS.ch. All rights reserved.
*
* This program and the accompanying materials are dual-licensed under
* either the terms of the Eclipse Public License v2.0 as published by
* the Eclipse Foundation
*
* or (per the licensee's choosing)
*
* under the terms of the GNU Lesser General Public License version 2.1
* as published by the Free Software Foundation.
*/
package ch.qos.logback.classic.util;
import ch.qos.logback.classic.ClassicConstants;
import ch.qos.logback.classic.LoggerContext;
import ch.qos.logback.classic.spi.Configurator;
import ch.qos.logback.classic.spi.ConfiguratorRank;
import ch.qos.logback.core.LogbackException;
import ch.qos.logback.core.joran.spi.JoranException;
import ch.qos.logback.core.spi.ContextAware;
import ch.qos.logback.core.spi.ContextAwareImpl;
import ch.qos.logback.core.util.CoreVersionUtil;
import ch.qos.logback.core.util.Loader;
import ch.qos.logback.core.util.StatusListenerConfigHelper;
import ch.qos.logback.core.util.VersionUtil;
import java.util.Comparator;
import java.util.List;
// contributors
// Ted Graham, Matt Fowles, see also http://jira.qos.ch/browse/LBCORE-32
/**
* This class contains logback's logic for automatic configuration
*
* @author Ceki Gulcu
*/
public class ContextInitializer {
/**
* @deprecated Please use ClassicConstants.AUTOCONFIG_FILE instead
*/
final public static String AUTOCONFIG_FILE = ClassicConstants.AUTOCONFIG_FILE;
/**
* @deprecated Please use ClassicConstants.TEST_AUTOCONFIG_FILE instead
*/
final public static String TEST_AUTOCONFIG_FILE = ClassicConstants.TEST_AUTOCONFIG_FILE;
/**
* @deprecated Please use ClassicConstants.CONFIG_FILE_PROPERTY instead
*/
final public static String CONFIG_FILE_PROPERTY = ClassicConstants.CONFIG_FILE_PROPERTY;
String[] INTERNAL_CONFIGURATOR_CLASSNAME_LIST = {"ch.qos.logback.classic.util.DefaultJoranConfigurator", "ch.qos.logback.classic.BasicConfigurator"};
final LoggerContext loggerContext;
final ContextAware contextAware;
public ContextInitializer(LoggerContext loggerContext) {
this.loggerContext = loggerContext;
this.contextAware = new ContextAwareImpl(loggerContext, this);
}
public void autoConfig() throws JoranException {
autoConfig(Configurator.class.getClassLoader());
}
public void autoConfig(ClassLoader classLoader) throws JoranException {
// see https://github.com/qos-ch/logback/issues/715
classLoader = Loader.systemClassloaderIfNull(classLoader);
checkVersions();
StatusListenerConfigHelper.installIfAsked(loggerContext);
// invoke custom configurators
List<Configurator> configuratorList = ClassicEnvUtil.loadFromServiceLoader(Configurator.class, classLoader);
configuratorList.sort(rankComparator);
if (configuratorList.isEmpty()) {
contextAware.addInfo("No custom configurators were discovered as a service.");
} else {
printConfiguratorOrder(configuratorList);
}
int authConfiguratorCount = authConfiguratorCount(configuratorList);
if (authConfiguratorCount > 1) {
contextAware.addError("Multiple custom configurators of rank AUTHENTICATING were discovered as a service. This is not allowed.");
contextAware.addError("Ensure that at most one AUTHENTICATING configurator exists on the classpath.");
return;
}
// invoke custom configurators
for (Configurator c : configuratorList) {
if (invokeConfigure(c) == Configurator.ExecutionStatus.DO_NOT_INVOKE_NEXT_IF_ANY)
return;
}
// invoke internal configurators
for (String configuratorClassName : INTERNAL_CONFIGURATOR_CLASSNAME_LIST) {
contextAware.addInfo("Trying to configure with " + configuratorClassName);
Configurator c = instantiateConfiguratorByClassName(configuratorClassName, classLoader);
if (c == null)
continue;
if (invokeConfigure(c) == Configurator.ExecutionStatus.DO_NOT_INVOKE_NEXT_IF_ANY)
return;
}
}
private int authConfiguratorCount(List<Configurator> configuratorList) {
int count = 0;
for (Configurator c : configuratorList) {
if (c.getClass().getAnnotation(ConfiguratorRank.class) != null
&& c.getClass().getAnnotation(ConfiguratorRank.class).value() == ConfiguratorRank.AUTHENTICATING) {
contextAware.addInfo("Configurator of rank AUTHENTICATING discovered: " + c.getClass().getName());
count++;
}
}
return count;
}
private void checkVersions() {
try {
String coreVersion = CoreVersionUtil.getCoreVersionBySelfDeclaredProperties();
String classicVersion = ClassicVersionUtil.getVersionBySelfDeclaredProperties();
VersionUtil.checkForVersionEquality(loggerContext, coreVersion, classicVersion, "logback-core", "logback-classic");
} catch (NoClassDefFoundError e) {
contextAware.addWarn("Missing ch.logback.core.util.VersionUtil class on classpath. The version of logback-core is probably older than 1.5.26.");
} catch (NoSuchMethodError e) {
contextAware.addWarn(e.toString());
contextAware.addWarn("The version of logback-core is probably older than 1.5.26.");
}
}
private Configurator instantiateConfiguratorByClassName(String configuratorClassName, ClassLoader classLoader) {
try {
Class<?> classObj = classLoader.loadClass(configuratorClassName);
return (Configurator) classObj.getConstructor().newInstance();
} catch (ReflectiveOperationException e) {
contextAware.addInfo("Instantiation failure: " + e.toString());
return null;
}
}
/**
*
* @param configurator
* @return ExecutionStatus
*/
private Configurator.ExecutionStatus invokeConfigure(Configurator configurator) {
try {
long start = System.currentTimeMillis();
contextAware.addInfo("Constructed configurator of type " + configurator.getClass());
configurator.setContext(loggerContext);
Configurator.ExecutionStatus status = configurator.configure(loggerContext);
printDuration(start, configurator, status);
return status;
} catch (Exception e) {
throw new LogbackException(String.format("Failed to initialize or to run Configurator: %s",
configurator != null ? configurator.getClass().getCanonicalName() : "null"), e);
}
}
private void printConfiguratorOrder(List<Configurator> configuratorList) {
contextAware.addInfo("Here is a list of configurators discovered as a service, by rank: ");
for (Configurator c : configuratorList) {
contextAware.addInfo(" " + c.getClass().getName());
}
contextAware.addInfo("They will be invoked in order until ExecutionStatus.DO_NOT_INVOKE_NEXT_IF_ANY is returned.");
}
private void printDuration(long start, Configurator configurator, Configurator.ExecutionStatus executionStatus) {
long end = System.currentTimeMillis();
long diff = end - start;
contextAware.addInfo(configurator.getClass().getName() + ".configure() call lasted " + diff + " milliseconds. ExecutionStatus=" + executionStatus);
}
private Configurator.ExecutionStatus attemptConfigurationUsingJoranUsingReflexion(ClassLoader classLoader) {
try {
Class<?> djcClass = classLoader.loadClass("ch.qos.logback.classic.util.DefaultJoranConfigurator");
Configurator c = (Configurator) djcClass.newInstance();
c.setContext(loggerContext);
return c.configure(loggerContext);
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException e) {
contextAware.addError("unexpected exception while instantiating DefaultJoranConfigurator", e);
return Configurator.ExecutionStatus.INVOKE_NEXT_IF_ANY;
}
}
Comparator<Configurator> rankComparator = new Comparator<Configurator>() {
@Override
public int compare(Configurator c1, Configurator c2) {
ConfiguratorRank r1 = c1.getClass().getAnnotation(ConfiguratorRank.class);
ConfiguratorRank r2 = c2.getClass().getAnnotation(ConfiguratorRank.class);
int value1 = r1 == null ? ConfiguratorRank.DEFAULT : r1.value();
int value2 = r2 == null ? ConfiguratorRank.DEFAULT : r2.value();
int result = compareRankValue(value1, value2);
// reverse the result for high to low sort
return (-result);
}
};
private int compareRankValue(int value1, int value2) {
if (value1 > value2)
return 1;
else if (value1 == value2)
return 0;
else return -1;
}
}