org.springframework.core.log.LogDelegateFactory Maven / Gradle / Ivy
/*
* Copyright 2002-2021 the original author or authors.
*
* Licensed 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
*
* https://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.springframework.core.log;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* Factory for common {@link Log} delegates with Spring's logging conventions.
*
* Mainly for internal use within the framework with Apache Commons Logging,
* typically in the form of the {@code spring-jcl} bridge but also compatible
* with other Commons Logging bridges.
*
* @author Rossen Stoyanchev
* @author Juergen Hoeller
* @since 5.1
* @see org.apache.commons.logging.LogFactory
*/
public final class LogDelegateFactory {
private LogDelegateFactory() {
}
/**
* Create a composite logger that delegates to a primary or falls back on a
* secondary logger if logging for the primary logger is not enabled.
*
This may be used for fallback logging from lower-level packages that
* logically should log together with some higher-level package but the two
* don't happen to share a suitable parent package (e.g. logging for the web
* and lower-level http and codec packages). For such cases the primary
* (class-based) logger can be wrapped with a shared fallback logger.
* @param primaryLogger primary logger to try first
* @param secondaryLogger secondary logger
* @param tertiaryLoggers optional vararg of further fallback loggers
* @return the resulting composite logger for the related categories
*/
public static Log getCompositeLog(Log primaryLogger, Log secondaryLogger, Log... tertiaryLoggers) {
List loggers = new ArrayList<>(2 + tertiaryLoggers.length);
loggers.add(primaryLogger);
loggers.add(secondaryLogger);
Collections.addAll(loggers, tertiaryLoggers);
return new CompositeLog(loggers);
}
/**
* Create a "hidden" logger with a category name prefixed with "_", thus
* precluding it from being enabled together with other log categories from
* the same package. This is useful for specialized output that is either
* too verbose or otherwise optional or unnecessary to see all the time.
* @param clazz the class for which to create a logger
* @return a Log with the category {@code "_" + fully-qualified class name}
*/
public static Log getHiddenLog(Class clazz) {
return getHiddenLog(clazz.getName());
}
/**
* Create a "hidden" logger with a category name prefixed with "_", thus
* precluding it from being enabled together with other log categories from
* the same package. This is useful for specialized output that is either
* too verbose or otherwise optional or unnecessary to see all the time.
* @param category the log category to use
* @return a Log with the category {@code "_" + category}
* @since 5.3.5
*/
public static Log getHiddenLog(String category) {
return LogFactory.getLog("_" + category);
}
}