问题说明
log4net 2.0.8.0
Delete log4net files for 10 days
log4net自动删除日志文件按照我的搜索习惯，先去log4net 官网查找相关资料，最终结果是log4net 官网所有章节并未提及到这个功能，于是我就 百度/必应 了log4net 自动删除指定天数之前日志的解决方案，于是在stackoverflow的网站上找到了一篇这样的提问文章 Can Log4Net Delete Log Files Automatically? ，此文章的疑问刚好与我的疑问想契合，在文章的评论区有大神给出了两个其他的解决方案，大概意思如下：
译文如下
1.创建自定义的 appender，继承于 RollingFileAppender类，如果你想拥有更多的控制，可以继承于 FileAppender类，然后使用自定义的appender 修改你的配置文件（修改appender元素下的内容）。
2.创建一个.bat的批处理文件，用来删除早于n天前的文件。然后在Windows下创建一个任务用来每天运行这个批处理文件。
原评论如下
I'm pretty sure that you can't do with the existing appender, although I can't confirm it.
However, I see two options:
-
Create your own appender, subclassing RollingFileAppender (or, if you want more control, subclass FileAppender). Then change your config file to use that appender (change the appender element).
-
Create a .bat file that deletes files older than x days (see: Batch file to delete files older than N days). Then create a task in Windows (http://support.microsoft.com/kb/308569) that runs this bat file e.g. every day.
扩展 RollingFileAppender
实现加载时删除指定时间之前的日志
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using log4net.Appender;
namespace ISail
{
public class IRollingFileAppender : RollingFileAppender
{
/// <summary>
/// 删除模式
/// </summary>
public enum DeleteMode
{
LastWriteTime = 0,
CreationTime = 1,
LastAccessTime = 2,
}
public int MaximumFileCount { get; set; }
/// <summary>
/// 自动删除N天之前的日志
/// </summary>
public int OutDateDays { get; set; }
/// <summary>
/// 选择删除时的匹配条件
/// </summary>
public DeleteMode DeleteStyle { get; set; }
public override void ActivateOptions()
{
base.ActivateOptions();
DeleteLogFilesForOutDate();
DeleteLogFilesForOverCount();
}
/// <summary>
/// 删除当前日志所在目录下的文件
/// </summary>
public void DeleteLogFilesForOutDate()
{
try
{
string strBasepath = System.IO.Path.GetDirectoryName(File);
foreach (string file in Directory.GetFiles(strBasepath))
{
DeleteLogFiles(file, DeleteStyle);
}
}
catch { }
}
/// <summary>
/// 删除超过指定数量的日志
/// </summary>
public void DeleteLogFilesForOverCount()
{
try
{
string strBasepath = System.IO.Path.GetDirectoryName(File);
int a = MaxSizeRollBackups;
int b = MaximumFileCount;
int n = a > b ? a : b;
DirectoryInfo di = new DirectoryInfo(strBasepath);
FileInfo[] query = di.GetFiles();
if (n >= query.Length) return;
if (DeleteStyle == DeleteMode.CreationTime)
{
var querySort = query.OrderByDescending(o => o.CreationTime).ToArray();
for (int i = n; i < querySort.Length; i++)
{
try
{
System.IO.File.Delete(querySort[i].FullName);
}
catch
{
}
}
}
else if (DeleteStyle == DeleteMode.LastAccessTime)
{
var querySort = query.OrderByDescending(o => o.LastAccessTime).ToArray();
for (int i = n; i < querySort.Length; i++)
{
try
{
System.IO.File.Delete(query[i].FullName);
}
catch
{
}
}
}
else if (DeleteStyle == DeleteMode.LastWriteTime)
{
var querySort = query.OrderByDescending(o => o.LastWriteTime).ToArray();
for (int i = n; i < querySort.Length; i++)
{
try
{
System.IO.File.Delete(querySort[i].FullName);
}
catch
{
}
}
}
}
catch { }
}
/// <summary>
/// 根据时间条件删除文件
/// </summary>
/// <param name="file"></param>
/// <param name="mode"></param>
private void DeleteLogFiles(string file, DeleteMode mode = DeleteMode.LastWriteTime)
{
try
{
int odd = OutDateDays;
if (string.IsNullOrWhiteSpace(file)) return;
if (System.IO.File.Exists(file) == false) return;
System.IO.FileInfo fi = new FileInfo(file);
if (mode == DeleteMode.CreationTime && fi.CreationTime < DateTime.Now.AddDays(-odd))
{
System.IO.File.Delete(file);
}
else if (mode == DeleteMode.LastWriteTime && fi.LastWriteTime < DateTime.Now.AddDays(-odd))
{
System.IO.File.Delete(file);
}
else if (mode == DeleteMode.LastAccessTime && fi.LastAccessTime < DateTime.Now.AddDays(-odd))
{
System.IO.File.Delete(file);
}
}
catch { }
}
}
}
app.config 或 web.config
<log4net>
<!--<appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">-->
<!--type属性使用自定义的命名空间ISail以及自定义的类 IRollingFileAppender -->
<appender name="RollingLogFileAppender" type="ISail.IRollingFileAppender">
<param name="File" value=".\\log\\"/>
<param name="AppendToFile" value="true"/>
<param name="MaxSizeRollBackups" value="10"/>
<!-- 自定义参数：日志目录下的最大文件数量，以 "删除依据" 为排序条件，越接近当前时间的保留 -->
<param name="MaximumFileCount" value="10"/>
<!-- 自定义参数： 根据 "删除依据" 删除3天前的数据-->
<param name="OutDateDays" value="3"/>
<!-- 自定义参数：删除依据-->
<!-- 创建时间 CreationTime-->
<!-- 访问时间 LastAccessTime-->
<!-- 最后修改时间 LastWriteTime-->
<param name="DeleteStyle" value="CreationTime"/>
<param name="MaximumFileSize" value="10MB" />
<param name="StaticLogFileName" value="false"/>
<param name="DatePattern" value="yyyy-MM-dd".log""/>
<param name="RollingStyle" value="Composite"/>
<layout type="log4net.Layout.PatternLayout">
<param name="ConversionPattern" value="%d [%t] %-5p %c - %m%n"/>
</layout>
</appender>
<root>
<level value="all"/>
<appender-ref ref="RollingLogFileAppender"/>
</root>
</log4net>