org.apache.logging.log4j.spi.Provider 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.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 Class loggerContextFactoryClass;
private final String threadContextMap;
private final Class threadContextMapClass;
private final String versions;
private final URL url;
private final WeakReference 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);
loggerContextFactoryClass = null;
threadContextMapClass = null;
versions = null;
}
public Provider(
final Integer priority,
final String versions,
final Class loggerContextFactoryClass) {
this(priority, versions, loggerContextFactoryClass, null);
}
public Provider(
final Integer priority,
final String versions,
final Class loggerContextFactoryClass,
final Class threadContextMapClass) {
this.url = null;
this.classLoader = null;
this.priority = priority;
this.loggerContextFactoryClass = loggerContextFactoryClass;
this.threadContextMapClass = threadContextMapClass;
this.className = null;
this.threadContextMap = null;
this.versions = versions;
}
/**
* Returns the Log4j API versions supported by the implementation.
* @return A String containing the Log4j versions supported.
*/
public String getVersions() {
return versions;
}
/**
* 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() {
if (loggerContextFactoryClass != null) {
return loggerContextFactoryClass.getName();
}
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 loadLoggerContextFactory() {
if (loggerContextFactoryClass != null) {
return loggerContextFactoryClass;
}
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() {
if (threadContextMapClass != null) {
return threadContextMapClass.getName();
}
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 loadThreadContextMap() {
if (threadContextMapClass != null) {
return threadContextMapClass;
}
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() {
final StringBuilder result = new StringBuilder("Provider[");
if (!DEFAULT_PRIORITY.equals(priority)) {
result.append("priority=").append(priority).append(", ");
}
if (threadContextMap != null) {
result.append("threadContextMap=").append(threadContextMap).append(", ");
} else if (threadContextMapClass != null) {
result.append("threadContextMapClass=").append(threadContextMapClass.getName());
}
if (className != null) {
result.append("className=").append(className).append(", ");
} else if (loggerContextFactoryClass != null) {
result.append("class=").append(loggerContextFactoryClass.getName());
}
if (url != null) {
result.append("url=").append(url);
}
final ClassLoader loader;
if (classLoader == null || (loader = classLoader.get()) == null) {
result.append(", classLoader=null(not reachable)");
} else {
result.append(", classLoader=").append(loader);
}
result.append("]");
return result.toString();
}
@Override
public boolean equals(final Object o) {
if (this == o) {
return true;
}
if (!(o instanceof Provider)) {
return false;
}
final Provider provider = (Provider) o;
if (priority != null ? !priority.equals(provider.priority) : provider.priority != null) {
return false;
}
if (className != null ? !className.equals(provider.className) : provider.className != null) {
return false;
}
if (loggerContextFactoryClass != null
? !loggerContextFactoryClass.equals(provider.loggerContextFactoryClass)
: provider.loggerContextFactoryClass != null) {
return false;
}
return versions != null ? versions.equals(provider.versions) : provider.versions == null;
}
@Override
public int hashCode() {
int result = priority != null ? priority.hashCode() : 0;
result = 31 * result + (className != null ? className.hashCode() : 0);
result = 31 * result + (loggerContextFactoryClass != null ? loggerContextFactoryClass.hashCode() : 0);
result = 31 * result + (versions != null ? versions.hashCode() : 0);
return result;
}
}