我使用 log4net.Appender.AdoNetAppender 附加程序。
我的 log4net 表有以下字段
[Date],[Thread],[Level],[Logger],[Message],[Exception]
我需要向 log4net 表添加另一个字段(例如 SalesId),但是如何在 xml 和代码中指定在记录错误或信息消息时记录“SalesId”?
例如
log.Info("SomeMessage", SalesId)
这是 log4net xml
<appender name="SalesDBAppender" type="log4net.Appender.AdoNetAppender">
<bufferSize value="1" />
<connectionType value ="System.Data.SqlClient.SqlConnection" />
<connectionString value="Data Source=..." />
<commandText value="INSERT INTO Log4Net ([Date],[Thread],[Level],[Logger],[Message],[Exception]) VALUES (@log_date, @thread, @log_level, @logger, @message, @exception)" />
<parameter>
<parameterName value="@log_date" />
<dbType value="DateTime" />
<layout type="log4net.Layout.RawTimeStampLayout" />
</parameter>
<parameter>
<parameterName value="@thread" />
<dbType value="String" />
<size value="255" />
<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="4000" />
<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>
1)修改命令文字:
INSERT INTO Log4Net ([Date],[Thread],[Level],[Logger],[Message],[Exception],[MyColumn]) VALUES (@log_date, @thread, @log_level, @logger, @message, @exception, @CustomColumn)
2)添加自定义列的参数定义:
<parameter>
<parameterName value="@CustomColumn"/>
<dbType value="String" />
<size value="255" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%property{CustomColumn}" />
</layout>
</parameter>
3)然后使用 log4net 的上下文之一将值传输到参数:
// thread properties...
log4net.LogicalThreadContext.Properties["CustomColumn"] = "Custom value";
log.Info("Message");
// ...or global properties
log4net.GlobalContext.Properties["CustomColumn"] = "Custom value";
Log4Net 中提供三种类型的日志记录上下文。
Log4Net.GlobalContext:- 此上下文在所有应用程序线程和域之间共享。如果两个线程在 GlobalContext 上设置相同的属性,则一个值将覆盖另一个值。
Log4Net.ThreadContext :- 此上下文范围仅限于调用线程。这里两个线程可以将相同的属性设置为不同的值,而不会相互覆盖。
Log4Net.ThreadLogicalContext :- 此上下文的行为与 ThreadContext 类似。如果您正在使用自定义线程池算法或托管 CLR,您可能会发现这个算法有一些用处。
将以下代码添加到您的program.cs文件中:
static void Main( string[] args )
{
log4net.Config.XmlConfigurator.Configure();
log4net.ThreadContext.Properties[ "myContext" ] = "Logging from Main";
Log.Info( "this is an info message" );
Console.ReadLine();
}
2)添加自定义列的参数定义:
<log4net>
<appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender">
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%logger (%property{myContext}) [%level]- %message%newline" />
</layout>
</appender>
</log4net>
这是一个带有一些个性化偏好的工作版本。我添加了一个自定义列来存储生成的异常代码。
1)将您的自定义列(此处的异常代码)添加到 Log4net 配置中:
<commandText value="INSERT INTO Log([Date],[Thread],[Level],[Logger],[Message],[Exception],[ExceptionCode])
VALUES (@log_date, @thread, @log_level, @logger, @message, @exception,@exceptionCode)" />
<parameter>
<parameterName value="@exceptionCode" />
<dbType value="String" />
<size value="11" />
<layout type="Common.Utils.LogHelper.Log4NetExtentedLoggingPatternLayout">
<conversionPattern value="%exceptionCode{Code}" />
</layout>
</parameter>
2)Log4NetExtentedLoggingCustomParameters.cs
namespace Common.Utils.LogHelper
{
public class Log4NetExtentedLoggingCustomParameters
{
public string ExceptionCode { get; set; }
public string Message { get; set; }
public override string ToString()
{
return Message;
}
}
}
3) Log4NetExtentedLoggingPatternConverter.cs
namespace Common.Utils.LogHelper
{
public class Log4NetExtentedLoggingPatternConverter : PatternConverter
{
protected override void Convert(TextWriter writer, object state)
{
if (state == null)
{
writer.Write(SystemInfo.NullText);
return;
}
var loggingEvent = state as LoggingEvent;
var messageObj = loggingEvent.MessageObject as Log4NetExtentedLoggingCustomParameters;
if (messageObj == null)
{
writer.Write(SystemInfo.NullText);
}
else
{
switch (this.Option.ToLower()) //this.Option = "Code"
{
case "code": //config conversionPattern parameter -> %exceptionCode{Code}
writer.Write(messageObj.ExceptionCode);
break;
default:
writer.Write(SystemInfo.NullText);
break;
}
}
}
}
}
4) Log4NetExtentedLoggingPatternLayout.cs
namespace Common.Utils.LogHelper
{
public class Log4NetExtentedLoggingPatternLayout : PatternLayout
{
public Log4NetExtentedLoggingPatternLayout()
{
var customConverter = new log4net.Util.ConverterInfo()
{
Name = "exceptionCode",
Type = typeof(Log4NetExtentedLoggingPatternConverter)
};
AddConverter(customConverter);
}
}
}
5) Logger.cs // 使用新列享受您的记录器! :)
namespace Common.Utils.LogHelper
{
public class Logger
{
static ILog Logger = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
public static string LogError(string message, Exception exception = null)
{
var logWithErrCode = GetLogWithErrorCode(message);
Logger.Error(logWithErrCode, exception);
return logWithErrCode.ExceptionCode;
}
private static Log4NetExtentedLoggingCustomParameters GetLogWithErrorCode(string message)
{
var logWithErrCode = new Log4NetExtentedLoggingCustomParameters();
logWithErrCode.ExceptionCode = GenerateErrorCode(); //this method is absent for simplicity. Use your own implementation
logWithErrCode.Message = message;
return logWithErrCode;
}
}
}
参考资料:
http://blog.stvjam.es/2014/01/logging-custom-objects-and-fields-with
如果您来到这里并使用 .net core 或更高版本,我使用的是 .net8,并且需要从 HttpContext 获取值并注入日志消息,您将需要替换那些“%aspnet-”属性使用自定义属性从参数的 conversionPattern 中获取,并使用中间件将这些属性注入到 log4net 上下文中。
例如:
<appender ...>
<!--other elements-->
<commandText value="INSERT INTO Log ([Date],[Thread],[Level],[Logger],[Message],[Exception],[User]) VALUES (@log_date, @thread, @log_level, @logger, @message, @exception, @identity)" />
<!--other elements-->
<parameter>
<parameterName value="@message" />
<!-- other settings -->
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date | [%property{log4net:HostName}] | [%property{URL}] | [%property{QUERY_STRING}]" />
</layout>
</parameter>
</appender>
然后在启动/程序文件中,设置一个中间件来注入这些自定义属性:
app.Use(async (context, next) => {
log4net.LogicalThreadContext.Properties["URL"] = context.Request.Path;
log4net.LogicalThreadContext.Properties["QUERY_STRING"] = context.Request.QueryString.ToString();
await next();
});