1.创建异常过滤器特性
using Log4Net.Controllers;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Filters;
namespace Log4NetTest
{
public class CustomerExceptionFilterAttribute : Attribute, IExceptionFilter
{
private readonly ILogger<CustomerExceptionFilterAttribute> _logger;
public CustomerExceptionFilterAttribute(ILogger<CustomerExceptionFilterAttribute> logger)
{
_logger = logger;
}
//当发生异常时，执行方法
public void OnException(ExceptionContext context)
{
//可以把错误信息写道日志里面
_logger.LogError(context.Exception.Message);
context.Result = new JsonResult(new
{
Success = false,
Msg = context.Exception.Message,
Position = context.Exception.StackTrace,
Data = context.RouteData.Values
});
}
}
}
2.使用异常特性
模拟一个报错，除数不为0
/// <summary>
/// 退出
/// </summary>
[HttpGet]
[TypeFilter(typeof(CustomerExceptionFilterAttribute))]
public async Task<IActionResult> Test()
{
int i = 0;
int j = 1 / i;//
return Ok();
}
TypeFilter：是把CustomerExceptionFilterAttribute注入到服务，
ServiceFilter:这里也可以使用ServiceFilter,然后在program中注入 builder.Services.AddScoped();
也可以全局注入，就不需要在控制器或方法上使用特性了
builder.Services.AddControllers(options =>
{
//全局
options.Filters.Add<CustomerExceptionFilterAttribute>(); // 注册自定义异常过滤器
});
执行后会返回下面的效果
3.配置Log4Net日志
3.1安装Nuget包
<PackageReference Include="Microsoft.Extensions.Logging.Log4Net.AspNetCore" Version="6.1.0" />
<PackageReference Include="log4net" Version="2.0.14" />
3.2创建log4Net的config配置文件
<?xml version="1.0" encoding="utf-8"?>
<log4net>
<!-- Define some output appenders -->
<appender name="rollingAppender" type="log4net.Appender.RollingFileAppender">
<!-- value="logs/log.log"-->
<file value="logs/" />
<!--追加日志内容-->
<appendToFile value="true" />
<!--防止多线程时不能写Log,官方说线程非安全-->
<lockingModel type="log4net.Appender.FileAppender+MinimalLock" />
<!--可以为:Once|Size|Date|Composite-->
<!--Composite为Size和Date的组合-->
<rollingStyle value="Composite" />
<!--当备份文件时,为文件名加的后缀-->
<datePattern value="yyyyMMdd/'log.log'" />
<!--日志最大个数,都是最新的-->
<!--rollingStyle节点为Size时,只能有value个日志-->
<!--rollingStyle节点为Composite时,每天有value个日志-->
<maxSizeRollBackups value="20" />
<!--可用的单位:KB|MB|GB-->
<maximumFileSize value="3MB" />
<!--置为true,当前最新日志文件名永远为file节中的名字-->
<staticLogFileName value="false" />
<!--输出级别在INFO和ERROR之间的日志-->
<filter type="log4net.Filter.LevelRangeFilter">
<param name="LevelMin" value="ALL" />
<param name="LevelMax" value="FATAL" />
</filter>
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %-5level %logger - %message%newline" />
</layout>
</appender>
<!-- error日志 -->
<appender name="errorAppender" type="log4net.Appender.RollingFileAppender">
<file value="logs/" />
<appendToFile value="true" />
<lockingModel type="log4net.Appender.FileAppender+MinimalLock" />
<rollingStyle value="Composite" />
<datePattern value="yyyyMMdd/'error.log'" />
<maxSizeRollBackups value="20" />
<maximumFileSize value="3MB" />
<staticLogFileName value="false" />
<filter type="log4net.Filter.LevelRangeFilter">
<param name="LevelMin" value="ERROR" />
<param name="LevelMax" value="ERROR" />
</filter>
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %-5level %logger - %message%newline" />
</layout>
</appender>
<!--SqlServer形式-->
<!--log4net日志配置：http://logging.apache.org/log4net/release/config-examples.html -->
<appender name="mysqlAppender" type="log4net.Appender.AdoNetAppender">
<!--日志缓存写入条数 设置为0时只要有一条就立刻写到数据库-->
<bufferSize value="0" />
<connectionType value="System.Data.SqlClient.SqlConnection,System.Data" />
<!--日志数据库连接串-->
<connectionString value="server=.;database=zhaoxi;uid=sa;pwd=peng@123" />
<commandText value="INSERT INTO logs(app_name,log_date, thread, level, logger, message,exception)VALUES(@app_name,@log_date, @thread,@log_level, @logger, @message, @exception);" />
<parameter>
<parameterName value="@app_name" />
<dbType value="String" />
<size value="100" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="api" />
</layout>
</parameter>
<parameter>
<parameterName value="@log_date" />
<dbType value="DateTime" />
<layout type="log4net.Layout.RawTimeStampLayout" />
</parameter>
<parameter>
<parameterName value="@thread" />
<dbType value="String" />
<size value="100" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%thread" />
</layout>
</parameter>
<parameter>
<parameterName value="@log_level" />
<dbType value="String" />
<size value="50" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%level" />
</layout>
</parameter>
<parameter>
<parameterName value="@logger" />
<dbType value="String" />
<size value="255" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%logger" />
</layout>
</parameter>
<parameter>
<parameterName value="@message" />
<dbType value="String" />
<size value="1000" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%message" />
</layout>
</parameter>
<parameter>
<parameterName value="@exception" />
<dbType value="String" />
<size value="2000" />
<layout type="log4net.Layout.ExceptionLayout" />
</parameter>
</appender>
<root>
<!--控制级别，由低到高: ALL|DEBUG|INFO|WARN|ERROR|FATAL|OFF-->
<!--OFF:0-->
<!--FATAL:FATAL-->
<!--ERROR: ERROR,FATAL-->
<!--WARN: WARN,ERROR,FATAL-->
<!--INFO: INFO,WARN,ERROR,FATAL-->
<!--DEBUG: INFO,WARN,ERROR,FATAL-->
<!--ALL: DEBUG,INFO,WARN,ERROR,FATAL-->
<priority value="ALL" />
<level value="INFO" />
<!--使用上面配置的那个规则，ref指定上面的规则名称-->
<appender-ref ref="rollingAppender" />
<appender-ref ref="errorAppender" />
<appender-ref ref="mysqlAppender" />
</root>
</log4net>
3.2注入日志服务
builder.Logging.AddLog4Net("Configs/log4net.Config");
这样就把日志写到了error.log.txt文件里了
补充：log4Net是对asp.net core 自带的日志系统的包装，已完成更多的日志功能，这边也可以写入到数据库等，也可以接入serilog结构化日志，可以更好的完成日志分析
