asp.net core 集成 log4net 日志框架

# 微信 2024-05-05 12:52 0 50 来源：云博客

asp.net core 集成 log4net 日志框架

Intro

在 asp.net core 中有些日志我们可能想输出到数据库或文件或elasticsearch等，如果不自己去实现一个 LoggerProvider 的话就需要借助第三方日志框架实现了，而一些第三方框架的实现大多比较完善和成熟，不失为一个好办法。

自己写了一个 log4net 的扩展 WeihanLi.Common.Logging.Log4Net，提供了在 .net core 中使用 log4net 的扩展

安装 nuget 包

通过 nuget 安装 WeihanLi.Common.Logging.Log4Net

使用

基本使用

ILoggerFactory loggerFactory = new LoggerFactory();loggerFactory.AddLog4Net(); // loggerFactory.AddLog4Net(log4netConfigFilePath);

你可以在 asp.net core 应用里你的 Startup 文件中使用下面代码进行配置

// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory) { loggerFactory.AddLog4Net(); // loggerFactory.AddLog4Net(log4netConfigFilePath); // ... }

默认使用当前目录下的 log4net.config 文件作为 log4net 的配置文件，如果不是需要自己设置 log4net 配置文件的路径。

log4net 配置参考示例配置

源码解析

项目源码

Log4NetLoggerProvider

实现记录日志的 ILogger

 internal class Log4NetLogger : ILogger { private readonly ILog _logger; public Log4NetLogger(string name) => _logger = LogManager.GetLogger(ApplicationHelper.ApplicationName, name); public IDisposable BeginScope<TState>(TState state) => NullScope.Instance; public bool IsEnabled(LogLevel logLevel) { switch (logLevel) { case LogLevel.Critical: return _logger.IsFatalEnabled; case LogLevel.Debug: case LogLevel.Trace: return _logger.IsDebugEnabled; case LogLevel.Error: return _logger.IsErrorEnabled; case LogLevel.Information: return _logger.IsInfoEnabled; case LogLevel.Warning: return _logger.IsWarnEnabled; case LogLevel.None: return false; default: throw new ArgumentOutOfRangeException(nameof(logLevel)); } } public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception, string> formatter) { if (!IsEnabled(logLevel)) { return; } if (formatter == null) { throw new ArgumentNullException(nameof(formatter)); } var message = formatter(state, exception); if (!(string.IsNullOrEmpty(message) && exception == null)) { switch (logLevel) { case LogLevel.Critical: _logger.Fatal(message, exception); break; case LogLevel.Debug: case LogLevel.Trace: _logger.Debug(message, exception); break; case LogLevel.Error: _logger.Error(message, exception); break; case LogLevel.Information: _logger.Info(message, exception); break; case LogLevel.Warning: _logger.Warn(message, exception); break; default: _logger.Warn($"Encountered unknown log level {logLevel}, writing out as Info."); _logger.Info(message, exception); break; } } } }

实现提供 logger 的 ILoggerProvider

 [ProviderAlias("log4net")] internal class Log4NetLoggerProvider : ILoggerProvider { private readonly ConcurrentDictionary<string, Log4NetLogger> _loggers = new ConcurrentDictionary<string, Log4NetLogger>(StringComparer.Ordinal); public Log4NetLoggerProvider(string confFilePath) { if (null == LogManager.GetAllRepositories()?.FirstOrDefault(_ => _.Name == ApplicationHelper.ApplicationName)) { XmlConfigurator.ConfigureAndWatch(LogManager.CreateRepository(ApplicationHelper.ApplicationName), new FileInfo(confFilePath)); } } public void Dispose() => _loggers.Clear(); public ILogger CreateLogger(string categoryName) => _loggers.GetOrAdd(categoryName, loggerName => new Log4NetLogger(loggerName)); }

添加 ILoggerFactory 扩展

 public static class Log4NetLoggerFactoryExtensions { public static ILoggerFactory AddLog4Net(this ILoggerFactory factory) { factory.AddProvider(new Log4NetLoggerProvider(ApplicationHelper.MapPath("log4net.config"))); return factory; } public static ILoggerFactory AddLog4Net(this ILoggerFactory factory, string configFile) { factory.AddProvider(new Log4NetLoggerProvider(configFile)); return factory; } }