基于log4net的支持动态文件名、按日期和大小自动分割文件的日志组件

最近处理一个日志功能，用log4net的配置不能完全满足要求，所以在其基础上简单封装了一下，支持以下功能：

1 零配置

内置默认配置，引用dll后不需要添加或修改任何配置文件也可以使用

2 动态指定文件路径和文件名

我们的需求是按请求来源和功能生成多个独立的日志文件，例如 /app编号/功能编号.txt 的结构，需要根据请求动态指定文件名称

3 按日期和大小自动分割文件，满足其中一个条件即可

来看实现

一、自定义读取配置文件的Appender

为了同时支持零配置和使用配置文件的方式，采用自定义一个用于读取配置项的Appender，初始化Logger时首先读取配置项中的同名Appender，如果存在使用配置参数，如果不存在则使用默认配置。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Rainstorm.Log4net
{
/// <summary>
/// http://blog.csdn.net/autfish /// </summary>
public class ReadParamAppender : log4net.Appender.AppenderSkeleton
{
private string _file;
public string File
{
get { return this._file; }
set { _file = value; }
}

private int _maxSizeRollBackups;
public int MaxSizeRollBackups
{
get { return this._maxSizeRollBackups; }
set { _maxSizeRollBackups = value; }
}

private bool _appendToFile = true;
public bool AppendToFile
{
get { return this._appendToFile; }
set { _appendToFile = value; }
}

private string _maximumFileSize;
public string MaximumFileSize
{
get { return this._maximumFileSize; }
set { _maximumFileSize = value; }
}

private string _layoutPattern;
public string LayoutPattern
{
get { return this._layoutPattern; }
set { _layoutPattern = value; }
}

private string _datePattern;
public string DatePattern
{
get { return this._datePattern; }
set { _datePattern = value; }
}

private string _level;
public string Level
{
get { return this._level; }
set { _level = value; }
}

protected override void Append(log4net.Core.LoggingEvent loggingEvent)
{
}
}
}

二、动态创建Logger工厂类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections.Concurrent;
using System.Configuration;

using log4net;
using log4net.Appender;
using log4net.Core;
using log4net.Layout;
using log4net.Repository;
using log4net.Repository.Hierarchy;

[assembly: log4net.Config.XmlConfigurator(Watch = true)]
namespace Rainstorm.Log4net
{
/// <summary>
/// http://blog.csdn.net/autfish /// </summary>
public static class CustomRollingFileLogger
{
private static readonly ConcurrentDictionary<string, ILog> loggerContainer = new ConcurrentDictionary<string, ILog>();

private static readonly Dictionary<string, ReadParamAppender> appenderContainer = new Dictionary<string, ReadParamAppender>();
private static object lockObj = new object();

//默认配置
private const int MAX_SIZE_ROLL_BACKUPS = 20;
private const string LAYOUT_PATTERN = "%d [%t] %-5p %c  - %m%n";
private const string DATE_PATTERN = "yyyyMMdd\".txt\"";
private const string MAXIMUM_FILE_SIZE = "256MB";
private const string LEVEL = "debug";

//读取配置文件并缓存
static CustomRollingFileLogger()
{
IAppender[] appenders = LogManager.GetRepository().GetAppenders();
for (int i = 0; i < appenders.Length; i++)
{
if (appenders[i] is ReadParamAppender)
{
ReadParamAppender appender = (ReadParamAppender)appenders[i];
if (appender.MaxSizeRollBackups == 0)
{
appender.MaxSizeRollBackups = MAX_SIZE_ROLL_BACKUPS;
}
if (appender.Layout != null && appender.Layout is log4net.Layout.PatternLayout)
{
appender.LayoutPattern = ((log4net.Layout.PatternLayout)appender.Layout).ConversionPattern;
}
if (string.IsNullOrEmpty(appender.LayoutPattern))
{
appender.LayoutPattern = LAYOUT_PATTERN;
}
if (string.IsNullOrEmpty(appender.DatePattern))
{
appender.DatePattern = DATE_PATTERN;
}
if (string.IsNullOrEmpty(appender.MaximumFileSize))
{
appender.MaximumFileSize = MAXIMUM_FILE_SIZE;
}
if (string.IsNullOrEmpty(appender.Level))
{
appender.Level = LEVEL;
}
lock(lockObj)
{
appenderContainer[appenders[i].Name] = appender;
}
}
}
}

public static ILog GetCustomLogger(string loggerName, string category = null, bool additivity = false)
{
return loggerContainer.GetOrAdd(loggerName, delegate(string name)
{
RollingFileAppender newAppender = null;
ReadParamAppender appender = null;
if (appenderContainer.ContainsKey(loggerName))
{
appender = appenderContainer[loggerName];
newAppender = GetNewFileApender(loggerName, string.IsNullOrEmpty(appender.File) ? GetFile(category, loggerName) : appender.File, appender.MaxSizeRollBackups,
appender.AppendToFile, true, appender.MaximumFileSize, RollingFileAppender.RollingMode.Composite, appender.DatePattern, appender.LayoutPattern);
}
else
{
newAppender = GetNewFileApender(loggerName, GetFile(category, loggerName), MAX_SIZE_ROLL_BACKUPS, true, true, MAXIMUM_FILE_SIZE, RollingFileAppender.RollingMode.Composite,
DATE_PATTERN, LAYOUT_PATTERN);
}
log4net.Repository.Hierarchy.Hierarchy repository = (log4net.Repository.Hierarchy.Hierarchy)LogManager.GetRepository();
Logger logger = repository.LoggerFactory.CreateLogger(repository, loggerName);
logger.Hierarchy = repository;
logger.Parent = repository.Root;
logger.Level = GetLoggerLevel(appender == null ? LEVEL : appender.Level);
logger.Additivity = additivity;
logger.AddAppender(newAppender);
logger.Repository.Configured = true;
return new LogImpl(logger);
});
}

//如果没有指定文件路径则在运行路径下建立 Log\{loggerName}.txt
private static string GetFile(string category, string loggerName)
{
if (string.IsNullOrEmpty(category))
{
return string.Format(@"Log\{0}.txt", loggerName);
}
else
{
return string.Format(@"Log\{0}\{1}.txt", category, loggerName);
}
}

private static Level GetLoggerLevel(string level)
{
if (!string.IsNullOrEmpty(level))
{
switch (level.ToLower().Trim())
{
case "debug":
return Level.Debug;

case "info":
return Level.Info;

case "warn":
return Level.Warn;

case "error":
return Level.Error;

case "fatal":
return Level.Fatal;
}
}
return Level.Debug;
}

private static RollingFileAppender GetNewFileApender(string appenderName, string file, int maxSizeRollBackups, bool appendToFile = true, bool staticLogFileName = false, string maximumFileSize = "5MB", RollingFileAppender.RollingMode rollingMode = RollingFileAppender.RollingMode.Composite, string datePattern = "yyyyMMdd\".txt\"", string layoutPattern = "%d [%t] %-5p %c  - %m%n")
{
RollingFileAppender appender = new RollingFileAppender
{
LockingModel = new FileAppender.MinimalLock(),
Name = appenderName,
File = file,
AppendToFile = appendToFile,
MaxSizeRollBackups = maxSizeRollBackups,
MaximumFileSize = maximumFileSize,
StaticLogFileName = staticLogFileName,
RollingStyle = rollingMode,
DatePattern = datePattern
};
PatternLayout layout = new PatternLayout(layoutPattern);
appender.Layout = layout;
layout.ActivateOptions();
appender.ActivateOptions();
return appender;
}
}
}

三、使用方法

3.1 零配置

ILog logger = CustomRollingFileLogger.GetCustomLogger("pay", "10001");
logger.Debug("debug message");

将在运行目录下生成 Log\10001\pay.txt

按日期分割日志文件，如果文件超过256M，也进行分割

3.2 使用配置文件

修改App.config/Web.config，添加或修改项

<configSections>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net"/>
</configSections>
<log4net>
<appender name="pay" type="Rainstorm.Log4net.ReadParamAppender">
<param name="file" value="D:\\log\\pay.txt"/>
<param name="appendToFile" value="true"/>
<param name="maxSizeRollBackups" value="100"/>
<param name="maximumFileSize" value="2MB"/>
<param name="datePattern" value="yyyyMMdd'.txt'"/>
<param name="level" value="debug"/>
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%d - %m%n"/>
</layout>
</appender>
<root>
<level value="INFO"/>
<appender-ref ref="pay"/>
</root>
</log4net>

ILog logger = CustomRollingFileLogger.GetCustomLogger("pay");
logger.Debug("debug message");

配置项均为可选项，具体含义如下：

file

文件路径

appendToFile

如果同名文件已存在，是否在文件中追加日志

maxSizeRollBackups

在发生文件分割时，最多保留的历史文件个数

maximumFileSize

设置按文件大小分割的阈值

datePattern

按日期分割时文件重命名规则

level

logger输出等级

layout

日志输出格式