JUL 执行原理和流程

https://www.bilibili.com/video/BV1iJ411H74S?p=10

日志原理解析

1. 初始化 LogManager
   1. Log Manager 加载 logging.properties 配置
   2. 添加 Logger 到 logManager
2. 从单例 LogManager 获取 Logger
3. 设置级别 Level，并指定日志记录 LogRecord
4. Filter 提供了日志级别之外更细粒度的控制
5. Handler 处理日志输出位置
6. Formatter 用来格式化 LogRecord

调试跟踪

Logger logger = Logger.getLogger("io.github.jihch");
return demandLogger(name, null, Reflection.getCallerClass());
LogManager manager = LogManager.getLogManager();	manager.demandLogger(name, resourceBundleName, caller);
manager.ensureLogManagerInitialized();
// Read configuration. owner.readPrimordialConfiguration(); // Create and retain Logger for the root of the namespace. owner.rootLogger = owner.new RootLogger(); owner.addLogger(owner.rootLogger);
super("", null, null, LogManager.this, true);