spring LoggingSystem 源码

  • 2022-08-12
  • 浏览 (551)

springboot LoggingSystem 代码

文件路径:/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/LoggingSystem.java

/*
 * Copyright 2012-2021 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.boot.logging;

import java.lang.reflect.Constructor;
import java.util.Collections;
import java.util.EnumSet;
import java.util.List;
import java.util.Set;

import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.StringUtils;

/**
 * Common abstraction over logging systems.
 *
 * @author Phillip Webb
 * @author Dave Syer
 * @author Andy Wilkinson
 * @author Ben Hale
 * @since 1.0.0
 */
public abstract class LoggingSystem {

	/**
	 * A System property that can be used to indicate the {@link LoggingSystem} to use.
	 */
	public static final String SYSTEM_PROPERTY = LoggingSystem.class.getName();

	/**
	 * The value of the {@link #SYSTEM_PROPERTY} that can be used to indicate that no
	 * {@link LoggingSystem} should be used.
	 */
	public static final String NONE = "none";

	/**
	 * The name used for the root logger. LoggingSystem implementations should ensure that
	 * this is the name used to represent the root logger, regardless of the underlying
	 * implementation.
	 */
	public static final String ROOT_LOGGER_NAME = "ROOT";

	private static final LoggingSystemFactory SYSTEM_FACTORY = LoggingSystemFactory.fromSpringFactories();

	/**
	 * Return the {@link LoggingSystemProperties} that should be applied.
	 * @param environment the {@link ConfigurableEnvironment} used to obtain value
	 * @return the {@link LoggingSystemProperties} to apply
	 * @since 2.4.0
	 */
	public LoggingSystemProperties getSystemProperties(ConfigurableEnvironment environment) {
		return new LoggingSystemProperties(environment);
	}

	/**
	 * Reset the logging system to be limit output. This method may be called before
	 * {@link #initialize(LoggingInitializationContext, String, LogFile)} to reduce
	 * logging noise until the system has been fully initialized.
	 */
	public abstract void beforeInitialize();

	/**
	 * Fully initialize the logging system.
	 * @param initializationContext the logging initialization context
	 * @param configLocation a log configuration location or {@code null} if default
	 * initialization is required
	 * @param logFile the log output file that should be written or {@code null} for
	 * console only output
	 */
	public void initialize(LoggingInitializationContext initializationContext, String configLocation, LogFile logFile) {
	}

	/**
	 * Clean up the logging system. The default implementation does nothing. Subclasses
	 * should override this method to perform any logging system-specific cleanup.
	 */
	public void cleanUp() {
	}

	/**
	 * Returns a {@link Runnable} that can handle shutdown of this logging system when the
	 * JVM exits. The default implementation returns {@code null}, indicating that no
	 * shutdown is required.
	 * @return the shutdown handler, or {@code null}
	 */
	public Runnable getShutdownHandler() {
		return null;
	}

	/**
	 * Returns a set of the {@link LogLevel LogLevels} that are actually supported by the
	 * logging system.
	 * @return the supported levels
	 */
	public Set<LogLevel> getSupportedLogLevels() {
		return EnumSet.allOf(LogLevel.class);
	}

	/**
	 * Sets the logging level for a given logger.
	 * @param loggerName the name of the logger to set ({@code null} can be used for the
	 * root logger).
	 * @param level the log level ({@code null} can be used to remove any custom level for
	 * the logger and use the default configuration instead)
	 */
	public void setLogLevel(String loggerName, LogLevel level) {
		throw new UnsupportedOperationException("Unable to set log level");
	}

	/**
	 * Returns a collection of the current configuration for all a {@link LoggingSystem}'s
	 * loggers.
	 * @return the current configurations
	 * @since 1.5.0
	 */
	public List<LoggerConfiguration> getLoggerConfigurations() {
		throw new UnsupportedOperationException("Unable to get logger configurations");
	}

	/**
	 * Returns the current configuration for a {@link LoggingSystem}'s logger.
	 * @param loggerName the name of the logger
	 * @return the current configuration
	 * @since 1.5.0
	 */
	public LoggerConfiguration getLoggerConfiguration(String loggerName) {
		throw new UnsupportedOperationException("Unable to get logger configuration");
	}

	/**
	 * Detect and return the logging system in use. Supports Logback and Java Logging.
	 * @param classLoader the classloader
	 * @return the logging system
	 */
	public static LoggingSystem get(ClassLoader classLoader) {
		String loggingSystemClassName = System.getProperty(SYSTEM_PROPERTY);
		if (StringUtils.hasLength(loggingSystemClassName)) {
			if (NONE.equals(loggingSystemClassName)) {
				return new NoOpLoggingSystem();
			}
			return get(classLoader, loggingSystemClassName);
		}
		LoggingSystem loggingSystem = SYSTEM_FACTORY.getLoggingSystem(classLoader);
		Assert.state(loggingSystem != null, "No suitable logging system located");
		return loggingSystem;
	}

	private static LoggingSystem get(ClassLoader classLoader, String loggingSystemClassName) {
		try {
			Class<?> systemClass = ClassUtils.forName(loggingSystemClassName, classLoader);
			Constructor<?> constructor = systemClass.getDeclaredConstructor(ClassLoader.class);
			constructor.setAccessible(true);
			return (LoggingSystem) constructor.newInstance(classLoader);
		}
		catch (Exception ex) {
			throw new IllegalStateException(ex);
		}
	}

	/**
	 * {@link LoggingSystem} that does nothing.
	 */
	static class NoOpLoggingSystem extends LoggingSystem {

		@Override
		public void beforeInitialize() {

		}

		@Override
		public void setLogLevel(String loggerName, LogLevel level) {

		}

		@Override
		public List<LoggerConfiguration> getLoggerConfigurations() {
			return Collections.emptyList();
		}

		@Override
		public LoggerConfiguration getLoggerConfiguration(String loggerName) {
			return null;
		}

	}

}

相关信息

spring 源码目录

相关文章

spring AbstractLoggingSystem 源码

spring DeferredLog 源码

spring DeferredLogFactory 源码

spring DeferredLogs 源码

spring DelegatingLoggingSystemFactory 源码

spring LogFile 源码

spring LogLevel 源码

spring LoggerConfiguration 源码

spring LoggerConfigurationComparator 源码

spring LoggerGroup 源码

0  赞