/*
* Copyright 2012 The Netty Project
*
* The Netty Project 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 io.netty.util.internal.logging;
/**
* Creates an {@link InternalLogger} or changes the default factory
* implementation. This factory allows you to choose what logging framework
* Netty should use. The default factory is {@link Slf4JLoggerFactory}. If SLF4J
* is not available, {@link Log4JLoggerFactory} is used. If Log4J is not available,
* {@link JdkLoggerFactory} is used. You can change it to your preferred
* logging framework before other Netty classes are loaded:
* <pre>
* {@link InternalLoggerFactory}.setDefaultFactory({@link Log4JLoggerFactory}.INSTANCE);
* </pre>
* Please note that the new default factory is effective only for the classes
* which were loaded after the default factory is changed. Therefore,
* {@link #setDefaultFactory(InternalLoggerFactory)} should be called as early
* as possible and shouldn't be called more than once.
*/
public abstract class
InternalLoggerFactory {
private static volatile
InternalLoggerFactory defaultFactory;
@
SuppressWarnings("UnusedCatchParameter")
private static
InternalLoggerFactory newDefaultFactory(
String name) {
InternalLoggerFactory f;
try {
f = new
Slf4JLoggerFactory(true);
f.
newInstance(
name).
debug("Using SLF4J as the default logging framework");
} catch (
Throwable ignore1) {
try {
f =
Log4JLoggerFactory.
INSTANCE;
f.
newInstance(
name).
debug("Using Log4J as the default logging framework");
} catch (
Throwable ignore2) {
try {
f =
Log4J2LoggerFactory.
INSTANCE;
f.
newInstance(
name).
debug("Using Log4J2 as the default logging framework");
} catch (
Throwable ignore3) {
f =
JdkLoggerFactory.
INSTANCE;
f.
newInstance(
name).
debug("Using java.util.logging as the default logging framework");
}
}
}
return
f;
}
/**
* Returns the default factory. The initial default factory is
* {@link JdkLoggerFactory}.
*/
public static
InternalLoggerFactory getDefaultFactory() {
if (
defaultFactory == null) {
defaultFactory =
newDefaultFactory(
InternalLoggerFactory.class.
getName());
}
return
defaultFactory;
}
/**
* Changes the default factory.
*/
public static void
setDefaultFactory(
InternalLoggerFactory defaultFactory) {
if (
defaultFactory == null) {
throw new
NullPointerException("defaultFactory");
}
InternalLoggerFactory.
defaultFactory =
defaultFactory;
}
/**
* Creates a new logger instance with the name of the specified class.
*/
public static
InternalLogger getInstance(
Class<?>
clazz) {
return
getInstance(
clazz.
getName());
}
/**
* Creates a new logger instance with the specified name.
*/
public static
InternalLogger getInstance(
String name) {
return
getDefaultFactory().
newInstance(
name);
}
/**
* Creates a new logger instance with the specified name.
*/
protected abstract
InternalLogger newInstance(
String name);
}