Question

我具有以下log4net配置：

<log4net>
    <appender name="Console" type="log4net.Appender.ConsoleAppender">
        <layout type='log4net.Layout.SerializedLayout, log4net.Ext.Json'>
            <renderer type='log4net.ObjectRenderer.JsonDotNetRenderer, log4net.Ext.Json.Net'>
                <DateFormatHandling value="IsoDateFormat" />
                <NullValueHandling value="Ignore" />
            </renderer>
            <converter>
              <name value="preparedMessage" />
              <type value="JsonLogs.CustomLayoutConverter" />
            </converter>
            <default />
            <remove value='message' />
            <remove value='ndc' />
            <member value='message:messageObject' />
            <member value='details:preparedMessage' />
        </layout> 
    </appender>

    <appender name="Console2" type="log4net.Appender.ConsoleAppender">
        <layout type="log4net.Layout.PatternLayout">
            <converter>
              <name value="preparedMessage" />
              <type value="JsonLogs.CustomLayoutConverter" />
            </converter>
            <conversionPattern value="%level %thread %logger - %preparedMessage%newline" />
        </layout>
    </appender>

    <root>
        <level value="DEBUG" />
        <appender-ref ref="Console" />
        <appender-ref ref="Console2" />
    </root>
</log4net>

使用我的自定义PatternLayoutConverter的以下实现：

namespace JsonLogs
{
    using System.IO;

    using log4net.Core;
    using log4net.Layout.Pattern;

    public class CustomLayoutConverter : PatternLayoutConverter
    {
        #region Methods

        protected override void Convert(TextWriter writer, LoggingEvent loggingEvent)
        {
            if (loggingEvent.MessageObject is string stringMessage)
            {
                writer.Write(new { message = stringMessage });
            }
            else
            {
                writer.Write(loggingEvent.RenderedMessage);
            }
        }

        #endregion
    }
}

由于某种原因，该转换器与Console2附加程序（非JSON驱动）完美配合，但不适用于输出为JSON的控制台附加程序。输出示例：

Console -> {"date":"2018-12-09T12:25:28.0529041+03:00","level":"INFO","appname":"JsonLogs.exe","logger":"JsonLogs.Program","thread":"1","message":"Test","details":"preparedMessage"}
Console2 -> INFO 1 JsonLogs.Program - { message = Test }

我的目标是使details始终位于JSON中，这就是为什么我引入了自己的转换器以捕获原始值并将它们包装在自定义对象中的原因。

我的配置错误吗？还是我想念什么？您能帮我解决这个问题吗？

谢谢

Answer 1

该问题似乎是log4net.Ext.Json的错误。我将在其GitLab上进行报告。到目前为止，我结束了我的自定义log4net布局，看起来像这样

public class CustomLayout : PatternLayout
{
    #region Public Methods and Operators

    public override void Format(TextWriter writer, LoggingEvent loggingEvent)
    {
        var message = loggingEvent.MessageObject.GetType().IsPrimitive || loggingEvent.MessageObject is string || loggingEvent.MessageObject is decimal || loggingEvent.MessageObject is BigInteger
            ? new { message = loggingEvent.MessageObject }
            : loggingEvent.MessageObject;

        writer.WriteLine(JsonConvert.SerializeObject(new
        {
            timestamp = loggingEvent.TimeStampUtc,
            threadId = loggingEvent.ThreadName,
            details = message,
            logger = loggingEvent.LoggerName,
            level = loggingEvent.Level.DisplayName,
            user = loggingEvent.UserName
        }));
    }

    #endregion
}

它可以满足我的需求，并且可以完全满足我的需求。

使用log4net.Ext.Json的自定义PatternLayoutConverter？

1 个答案: