/*
* 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.spi;
import java.lang.ref.WeakReference;
import java.net.URL;
import java.util.Properties;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.status.StatusLogger;
/**
* Model class for a Log4j 2 provider. The properties in this class correspond to the properties used in a
* {@code META-INF/log4j-provider.properties} file. Note that this class is automatically created by Log4j and should
* not be used by providers.
*/
public class Provider {
/**
* Property name to set for a Log4j 2 provider to specify the priority of this implementation.
*/
public static final String FACTORY_PRIORITY = "FactoryPriority";
/**
* Property name to set to the implementation of {@link org.apache.logging.log4j.spi.ThreadContextMap}.
*/
public static final String THREAD_CONTEXT_MAP = "ThreadContextMap";
/**
* Property name to set to the implementation of {@link org.apache.logging.log4j.spi.LoggerContextFactory}.
*/
public static final String LOGGER_CONTEXT_FACTORY = "LoggerContextFactory";
private static final Integer DEFAULT_PRIORITY = Integer.valueOf(-1);
private static final Logger LOGGER = StatusLogger.getLogger();
private final Integer priority;
private final String className;
private final String threadContextMap;
private final URL url;
private final WeakReference<ClassLoader> classLoader;
public Provider(final Properties props, final URL url, final ClassLoader classLoader) {
this.url = url;
this.classLoader = new WeakReference<>(classLoader);
final String weight = props.getProperty(FACTORY_PRIORITY);
priority = weight == null ? DEFAULT_PRIORITY : Integer.valueOf(weight);
className = props.getProperty(LOGGER_CONTEXT_FACTORY);
threadContextMap = props.getProperty(THREAD_CONTEXT_MAP);
}
/**
* Gets the priority (natural ordering) of this Provider.
*
* @return the priority of this Provider
*/
public Integer getPriority() {
return priority;
}
/**
* Gets the class name of the {@link org.apache.logging.log4j.spi.LoggerContextFactory} implementation of this
* Provider.
*
* @return the class name of a LoggerContextFactory implementation
*/
public String getClassName() {
return className;
}
/**
* Loads the {@link org.apache.logging.log4j.spi.LoggerContextFactory} class specified by this Provider.
*
* @return the LoggerContextFactory implementation class or {@code null} if there was an error loading it
*/
public Class<? extends LoggerContextFactory> loadLoggerContextFactory() {
if (className == null) {
return null;
}
final ClassLoader loader = classLoader.get();
if (loader == null) {
return null;
}
try {
final Class<?> clazz = loader.loadClass(className);
if (LoggerContextFactory.class.isAssignableFrom(clazz)) {
return clazz.asSubclass(LoggerContextFactory.class);
}
} catch (final Exception e) {
LOGGER.error("Unable to create class {} specified in {}", className, url.toString(), e);
}
return null;
}
/**
* Gets the class name of the {@link org.apache.logging.log4j.spi.ThreadContextMap} implementation of this Provider.
*
* @return the class name of a ThreadContextMap implementation
*/
public String getThreadContextMap() {
return threadContextMap;
}
/**
* Loads the {@link org.apache.logging.log4j.spi.ThreadContextMap} class specified by this Provider.
*
* @return the ThreadContextMap implementation class or {@code null} if there was an error loading it
*/
public Class<? extends ThreadContextMap> loadThreadContextMap() {
if (threadContextMap == null) {
return null;
}
final ClassLoader loader = classLoader.get();
if (loader == null) {
return null;
}
try {
final Class<?> clazz = loader.loadClass(threadContextMap);
if (ThreadContextMap.class.isAssignableFrom(clazz)) {
return clazz.asSubclass(ThreadContextMap.class);
}
} catch (final Exception e) {
LOGGER.error("Unable to create class {} specified in {}", threadContextMap, url.toString(), e);
}
return null;
}
/**
* Gets the URL containing this Provider's Log4j details.
*
* @return the URL corresponding to the Provider {@code META-INF/log4j-provider.properties} file
*/
public URL getUrl() {
return url;
}
@Override
public String toString() {
String result = "Provider[";
if (!DEFAULT_PRIORITY.equals(priority)) {
result += "priority=" + priority + ", ";
}
if (threadContextMap != null) {
result += "threadContextMap=" + threadContextMap + ", ";
}
if (className != null) {
result += "className=" + className + ", ";
}
result += "url=" + url;
final ClassLoader loader = classLoader.get();
if (loader == null) {
result += ", classLoader=null(not reachable)";
} else {
result += ", classLoader=" + loader;
}
result += "]";
return result;
}
}