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Author: HuiFer
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源码阅读仓库: SourceHot-spring-boot
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包路径:
org.springframework.boot.logging
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日志级别:
org.springframework.boot.logging.LogLevel
public enum LogLevel { TRACE, DEBUG, INFO, WARN, ERROR, FATAL, OFF }
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org.springframework.boot.logging.java.JavaLoggingSystem
static { // KEY : springBoot 定义的日志级别, value: jdk 定义的日志级别 LEVELS.map(LogLevel.TRACE, Level.FINEST); LEVELS.map(LogLevel.DEBUG, Level.FINE); LEVELS.map(LogLevel.INFO, Level.INFO); LEVELS.map(LogLevel.WARN, Level.WARNING); LEVELS.map(LogLevel.ERROR, Level.SEVERE); LEVELS.map(LogLevel.FATAL, Level.SEVERE); LEVELS.map(LogLevel.OFF, Level.OFF); }
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LEVELS 对象
protected static class LogLevels<T> { /** * key : SpringBoot 中定义的日志级别, value: 其他日志框架的日志级别 */ private final Map<LogLevel, T> systemToNative; /** * key : 其他日志框架的日志级别 , value: springBoot 中定义中定义的日志级别 */ private final Map<T, LogLevel> nativeToSystem; }
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抽象类
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org.springframework.boot.logging.LoggingSystem
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一个 map 对象:
SYSTEMS
/** * key: 第三方日志框架的类 value: springBoot 中的处理类 */ private static final Map<String, String> SYSTEMS; static { Map<String, String> systems = new LinkedHashMap<>(); systems.put("ch.qos.logback.core.Appender", "org.springframework.boot.logging.logback.LogbackLoggingSystem"); systems.put("org.apache.logging.log4j.core.impl.Log4jContextFactory", "org.springframework.boot.logging.log4j2.Log4J2LoggingSystem"); systems.put("java.util.logging.LogManager", "org.springframework.boot.logging.java.JavaLoggingSystem"); SYSTEMS = Collections.unmodifiableMap(systems); }
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各个抽象方法
方法名称 作用 beforeInitialize 初始化之前调用,目的是减少日志输出 initialize 初始化日志 cleanUp 清除日志 getShutdownHandler getSupportedLogLevels 获取支持的日志级别 setLogLevel 设置日志级别 getLoggerConfigurations 获取日志配置
public static LoggingSystem get(ClassLoader classLoader) {
// 获取系统属性
String loggingSystem = System.getProperty(SYSTEM_PROPERTY);
if (StringUtils.hasLength(loggingSystem)) {
// 是不是NONE
if (NONE.equals(loggingSystem)) {
// 空的日志系统
return new NoOpLoggingSystem();
}
return get(classLoader, loggingSystem);
}
// 循环所有日志,
return SYSTEMS.entrySet().stream().filter((entry) -> ClassUtils.isPresent(entry.getKey(), classLoader))
.map((entry) ->
// 实例化具体日志
get(classLoader, entry.getValue())).findFirst()
.orElseThrow(() -> new IllegalStateException("No suitable logging system located"));
}
- 实例化日志系统
private static LoggingSystem get(ClassLoader classLoader, String loggingSystemClass) {
try {
Class<?> systemClass = ClassUtils.forName(loggingSystemClass, classLoader);
Constructor<?> constructor = systemClass.getDeclaredConstructor(ClassLoader.class);
constructor.setAccessible(true);
return (LoggingSystem) constructor.newInstance(classLoader);
}
catch (Exception ex) {
throw new IllegalStateException(ex);
}
}
- 默认日志:
org.springframework.boot.logging.logback.LogbackLoggingSystem
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初始化之前
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链路
org.springframework.boot.context.logging.LoggingApplicationListener#onApplicationEvent
org.springframework.boot.context.logging.LoggingApplicationListener#onApplicationStartingEvent
org.springframework.boot.logging.LoggingSystem#beforeInitialize
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因为前文中我们已知对象是:
org.springframework.boot.logging.logback.LogbackLoggingSystem
直接看这个类的beforeInitialize
方法@Override public void beforeInitialize() { // 日志上下文 LoggerContext loggerContext = getLoggerContext(); // 是否初始化 if (isAlreadyInitialized(loggerContext)) { return; } // 父类方法 super.beforeInitialize(); // 添加过滤器 loggerContext.getTurboFilterList().add(FILTER); }
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初始化之前的的操作完成了初始化方法开始
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org.springframework.boot.context.logging.LoggingApplicationListener#onApplicationEnvironmentPreparedEvent
private void onApplicationEnvironmentPreparedEvent(ApplicationEnvironmentPreparedEvent event) { if (this.loggingSystem == null) { this.loggingSystem = LoggingSystem.get(event.getSpringApplication().getClassLoader()); } initialize(event.getEnvironment(), event.getSpringApplication().getClassLoader()); }
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org.springframework.boot.context.logging.LoggingApplicationListener#initializeSystem
protected void initialize(ConfigurableEnvironment environment, ClassLoader classLoader) { new LoggingSystemProperties(environment).apply(); this.logFile = LogFile.get(environment); if (this.logFile != null) { this.logFile.applyToSystemProperties(); } this.loggerGroups = new LoggerGroups(DEFAULT_GROUP_LOGGERS); // 早期 的日志级别 initializeEarlyLoggingLevel(environment); // 初始化日志系统 initializeSystem(environment, this.loggingSystem, this.logFile); // 初始化日志级别 initializeFinalLoggingLevels(environment, this.loggingSystem); registerShutdownHookIfNecessary(environment, this.loggingSystem); }
private void initializeSystem(ConfigurableEnvironment environment, LoggingSystem system, LogFile logFile) { LoggingInitializationContext initializationContext = new LoggingInitializationContext(environment); String logConfig = environment.getProperty(CONFIG_PROPERTY); if (ignoreLogConfig(logConfig)) { // 日志系统初始化 system.initialize(initializationContext, null, logFile); } else { try { ResourceUtils.getURL(logConfig).openStream().close(); system.initialize(initializationContext, logConfig, logFile); } catch (Exception ex) { // NOTE: We can't use the logger here to report the problem System.err.println("Logging system failed to initialize using configuration from '" + logConfig + "'"); ex.printStackTrace(System.err); throw new IllegalStateException(ex); } } }
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org.springframework.boot.logging.logback.LogbackLoggingSystem#initialize
@Override public void initialize(LoggingInitializationContext initializationContext, String configLocation, LogFile logFile) { LoggerContext loggerContext = getLoggerContext(); if (isAlreadyInitialized(loggerContext)) { return; } // 日志初始化 super.initialize(initializationContext, configLocation, logFile); loggerContext.getTurboFilterList().remove(FILTER); markAsInitialized(loggerContext); if (StringUtils.hasText(System.getProperty(CONFIGURATION_FILE_PROPERTY))) { getLogger(LogbackLoggingSystem.class.getName()).warn("Ignoring '" + CONFIGURATION_FILE_PROPERTY + "' system property. Please use 'logging.config' instead."); } }
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org.springframework.boot.logging.AbstractLoggingSystem#initializeWithConventions
private void initializeWithConventions(LoggingInitializationContext initializationContext, LogFile logFile) { String config = getSelfInitializationConfig(); if (config != null && logFile == null) { // self initialization has occurred, reinitialize in case of property changes reinitialize(initializationContext); return; } if (config == null) { config = getSpringInitializationConfig(); } if (config != null) { loadConfiguration(initializationContext, config, logFile); return; } // 加载默认配置 loadDefaults(initializationContext, logFile); }
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org.springframework.boot.logging.logback.LogbackLoggingSystem#loadDefaults
@Override protected void loadDefaults(LoggingInitializationContext initializationContext, LogFile logFile) { LoggerContext context = getLoggerContext(); stopAndReset(context); boolean debug = Boolean.getBoolean("logback.debug"); if (debug) { StatusListenerConfigHelper.addOnConsoleListenerInstance(context, new OnConsoleStatusListener()); } LogbackConfigurator configurator = debug ? new DebugLogbackConfigurator(context) : new LogbackConfigurator(context); Environment environment = initializationContext.getEnvironment(); context.putProperty(LoggingSystemProperties.LOG_LEVEL_PATTERN, environment.resolvePlaceholders("${logging.pattern.level:${LOG_LEVEL_PATTERN:%5p}}")); context.putProperty(LoggingSystemProperties.LOG_DATEFORMAT_PATTERN, environment.resolvePlaceholders( "${logging.pattern.dateformat:${LOG_DATEFORMAT_PATTERN:yyyy-MM-dd HH:mm:ss.SSS}}")); context.putProperty(LoggingSystemProperties.ROLLING_FILE_NAME_PATTERN, environment .resolvePlaceholders("${logging.pattern.rolling-file-name:${LOG_FILE}.%d{yyyy-MM-dd}.%i.gz}")); new DefaultLogbackConfiguration(initializationContext, logFile).apply(configurator); context.setPackagingDataEnabled(true); }
@Override public void initialize(LoggingInitializationContext initializationContext, String configLocation, LogFile logFile) { LoggerContext loggerContext = getLoggerContext(); // 是否加载过 if (isAlreadyInitialized(loggerContext)) { return; } // 日志初始化 super.initialize(initializationContext, configLocation, logFile); // 删除 FILTER loggerContext.getTurboFilterList().remove(FILTER); // 初始化标记 markAsInitialized(loggerContext); if (StringUtils.hasText(System.getProperty(CONFIGURATION_FILE_PROPERTY))) { getLogger(LogbackLoggingSystem.class.getName()).warn("Ignoring '" + CONFIGURATION_FILE_PROPERTY + "' system property. Please use 'logging.config' instead."); } }
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标记
markAsInitialized
private void markAsInitialized(LoggerContext loggerContext) { loggerContext.putObject(LoggingSystem.class.getName(), new Object()); }
此时日志初始化完成。
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getStandardConfigLocations
这个方法定义了默认配置文件有哪些。@Override protected String[] getStandardConfigLocations() { return new String[] { "logback-test.groovy", "logback-test.xml", "logback.groovy", "logback.xml" }; }
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切回
org.springframework.boot.logging.AbstractLoggingSystem#initializeWithConventions
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添加依赖
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-logging</artifactId> <version>${revision}</version> </dependency>
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添加配置文件
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此时配置文件地址出现了
protected String getSelfInitializationConfig() { // 寻找配置文件 return findConfig(getStandardConfigLocations()); }
@Override protected String[] getStandardConfigLocations() { return new String[] { "logback-test.groovy", "logback-test.xml", "logback.groovy", "logback.xml" }; }
private String findConfig(String[] locations) { for (String location : locations) { ClassPathResource resource = new ClassPathResource(location, this.classLoader); if (resource.exists()) { return "classpath:" + location; } } return null; }
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此时自定义配置文件如何获取的已经明了。
@Override
protected void reinitialize(LoggingInitializationContext initializationContext) {
// 日志上下文重新设置
getLoggerContext().reset();
getLoggerContext().getStatusManager().clear();
// 加载配置文件
loadConfiguration(initializationContext, getSelfInitializationConfig(), null);
}
@Override
protected void loadConfiguration(LoggingInitializationContext initializationContext, String location,
LogFile logFile) {
// 父类方法
super.loadConfiguration(initializationContext, location, logFile);
// 获取上下文
LoggerContext loggerContext = getLoggerContext();
// 停止并且重启
stopAndReset(loggerContext);
try {
// 配置文件加载
configureByResourceUrl(initializationContext, loggerContext, ResourceUtils.getURL(location));
}
catch (Exception ex) {
throw new IllegalStateException("Could not initialize Logback logging from " + location, ex);
}
List<Status> statuses = loggerContext.getStatusManager().getCopyOfStatusList();
StringBuilder errors = new StringBuilder();
for (Status status : statuses) {
if (status.getLevel() == Status.ERROR) {
errors.append((errors.length() > 0) ? String.format("%n") : "");
errors.append(status.toString());
}
}
if (errors.length() > 0) {
throw new IllegalStateException(String.format("Logback configuration error detected: %n%s", errors));
}
}
private void configureByResourceUrl(LoggingInitializationContext initializationContext, LoggerContext loggerContext,
URL url) throws JoranException {
if (url.toString().endsWith("xml")) {
// logback 日志操作
JoranConfigurator configurator = new SpringBootJoranConfigurator(initializationContext);
// 设置上下文
configurator.setContext(loggerContext);
// 执行配置
configurator.doConfigure(url);
}
else {
new ContextInitializer(loggerContext).configureByResource(url);
}
}
执行配置属于 logback 操作源码不在此进行分析。