asp.net Forums 之配置，缓存，多数据访问
在上一篇文章中，我谈到了asp.net Forums 之控件研究，这次我们来谈谈asp.net Forums 的配置、缓存和多数据访问。
一、配置
ANF的配置是通过ForumConfiguration类，ForumConfiguration类位于AspNetForums.Configuration命名空间下。
代码
#region
VSS
/*
* $Header: /HiForums/Components/Configuration/ForumConfiguration.cs 1 05-10-26 15:04 Jacky $
*
* $History: ForumConfiguration.cs $
*
* ***************** Version 1 *****************
* User: Jacky Date: 05-10-26 Time: 15:04
* Created in $/HiForums/Components/Configuration
*
* ***************** Version 1 *****************
* User: Jacky Date: 05-10-21 Time: 14:20
* Created in $/HiForums/Components/Configuration
*
* ***************** Version 3 *****************
* User: Jacky Date: 05-09-20 Time: 19:23
* Updated in $/ASP.NET Forums/Components/Configuration
*
* ***************** Version 2 *****************
* User: Jacky Date: 05-09-20 Time: 1:36
* Updated in $/ASP.NET Forums/Components/Configuration
*/
#endregion
using
System;
using
System.Collections;
using
System.Collections.Specialized;
using
System.IO;
using
System.Web;
using
System.Web.Caching;
using
System.Xml;
using
System.Configuration;
using
System.Xml.Serialization;
using
AspNetForums.Components;
using
AspNetForums.Enumerations;
namespace
AspNetForums.Configuration
{
//
*********************************************************************
//
ForumConfiguration
//
///
<summary>
///
读取论坛配置信息,根据CS结构重构.
///
by venjiang 2005/10/25
///
</summary>
///
//
***********************************************************************/
public
class
ForumConfiguration
{
#region
成员字段
public
static
readonly
string
CacheKey
=
"
ForumsConfiguration
"
;
private
Hashtable providers
=
new
Hashtable();
private
Hashtable extensions
=
new
Hashtable();
private
static
readonly
Cache cache
=
HttpRuntime.Cache;
private
string
defaultProvider;
private
string
defaultLanguage;
private
string
forumFilesPath;
private
bool
disableBackgroundThreads
=
false
;
private
bool
disableIndexing
=
false
;
private
bool
disableEmail
=
false
;
private
string
passwordEncodingFormat
=
"
unicode
"
;
private
int
threadIntervalEmail
=
15
;
private
int
threadIntervalStats
=
15
;
//
private SystemType systemType = SystemType.Self;
private
short
smtpServerConnectionLimit
=
-
1
;
private
bool
enableLatestVersionCheck
=
true
;
private
string
uploadFilesPath
=
"
/Upload/
"
;
private
XmlDocument XmlDoc
=
null
;
#endregion
#region
构造器
public
ForumConfiguration(XmlDocument doc)
{
XmlDoc
=
doc;
LoadValuesFromConfigurationXml();
}
#endregion
#region
获取XML节点
public
XmlNode GetConfigSection(
string
nodePath)
{
return
XmlDoc.SelectSingleNode(nodePath);
}
#endregion
/*
public static ForumConfiguration GetConfig()
{
return (ForumConfiguration) ConfigurationSettings.GetConfig("forums/forums");
}
*/
#region
获取配置信息实例
public
static
ForumConfiguration GetConfig()
{
ForumConfiguration config
=
cache.Get(CacheKey)
as
ForumConfiguration;
if
(config
==
null
)
{
string
path;
if
(HttpContext.Current
!=
null
)
path
=
HttpContext.Current.Server.MapPath(
"
~/Forums.config
"
);
else
path
=
Directory.GetCurrentDirectory()
+
Path.DirectorySeparatorChar
+
"
Forums.config
"
;
XmlDocument doc
=
new
XmlDocument();
doc.Load(path);
config
=
new
ForumConfiguration(doc);
cache.Insert(CacheKey,config,
new
CacheDependency(path),DateTime.MaxValue,TimeSpan.Zero,CacheItemPriority.AboveNormal,
null
);
//
cache.ReSetFactor(config.CacheFactor);
}
return
config;
}
#endregion
#region
加载配置文件设置
internal
void
LoadValuesFromConfigurationXml()
{
XmlNode node
=
GetConfigSection(
"
Forums/Core
"
);
XmlAttributeCollection attributeCollection
=
node.Attributes;
//
默认数据提供者
XmlAttribute att
=
attributeCollection[
"
defaultProvider
"
];
if
(att
!=
null
)
defaultProvider
=
att.Value;
//
默认语言
att
=
attributeCollection[
"
defaultLanguage
"
];
if
(att
!=
null
)
defaultLanguage
=
att.Value;
else
defaultLanguage
=
"
zh-CN
"
;
//
论坛路径
att
=
attributeCollection[
"
forumFilesPath
"
];
if
(att
!=
null
)
forumFilesPath
=
att.Value;
else
forumFilesPath
=
"
/
"
;
//
禁用后台线程
att
=
attributeCollection[
"
disableThreading
"
];
if
(att
!=
null
)
disableBackgroundThreads
=
bool
.Parse(att.Value);
else
disableBackgroundThreads
=
false
;
//
禁止索引
att
=
attributeCollection[
"
disableIndexing
"
];
if
(att
!=
null
)
disableIndexing
=
bool
.Parse(att.Value);
else
disableIndexing
=
false
;
//
禁止邮件
att
=
attributeCollection[
"
disableEmail
"
];
if
(att
!=
null
)
disableEmail
=
bool
.Parse(att.Value);
else
disableEmail
=
false
;
//
密码加密格式
att
=
attributeCollection[
"
passwordEncodingFormat
"
];
if
(att
!=
null
)
passwordEncodingFormat
=
att.Value;
else
passwordEncodingFormat
=
"
unicode
"
;
//
后中统计状态
att
=
attributeCollection[
"
threadIntervalStats
"
];
if
(att
!=
null
)
threadIntervalStats
=
int
.Parse(att.Value);
else
threadIntervalStats
=
15
;
//
邮件队列发送间隔
att
=
attributeCollection[
"
threadIntervalEmail
"
];
if
(att
!=
null
)
threadIntervalEmail
=
int
.Parse(att.Value);
else
threadIntervalEmail
=
15
;
//
SMTP服务器设置
att
=
attributeCollection[
"
smtpServerConnectionLimit
"
];
if
(att
!=
null
)
smtpServerConnectionLimit
=
short
.Parse(att.Value);
else
smtpServerConnectionLimit
=
-
1
;
//
版本检查
att
=
attributeCollection[
"
enableLatestVersionCheck
"
];
if
(att
!=
null
)
enableLatestVersionCheck
=
bool
.Parse(att.Value);
//
上传文件路径
att
=
attributeCollection[
"
uploadFilesPath
"
];
if
(att
!=
null
)
uploadFilesPath
=
att.Value;
//
读取子节点
foreach
(XmlNode child
in
node.ChildNodes)
{
if
(child.Name
==
"
providers
"
)
GetProviders(child, providers);
if
(child.Name
==
"
extensionModules
"
)
GetProviders(child, extensions);
}
}
#endregion
#region
获取配置文件节点Provider
internal
void
GetProviders(XmlNode node, Hashtable table)
{
foreach
(XmlNode provider
in
node.ChildNodes)
{
switch
(provider.Name)
{
case
"
add
"
:
table.Add(provider.Attributes[
"
name
"
].Value,
new
Provider(provider.Attributes));
break
;
case
"
remove
"
:
table.Remove(provider.Attributes[
"
name
"
].Value);
break
;
case
"
clear
"
:
table.Clear();
break
;
}
}
}
#endregion
#region
公有属性
//
Properties
//
public
string
DefaultLanguage
{
get
{
return
defaultLanguage; }
}
public
string
ForumFilesPath
{
get
{
return
forumFilesPath; }
}
public
string
DefaultProvider
{
get
{
return
defaultProvider; }
}
public
Hashtable Providers
{
get
{
return
providers; }
}
public
Hashtable Extensions
{
get
{
return
extensions; }
}
public
bool
IsBackgroundThreadingDisabled
{
get
{
return
disableBackgroundThreads; }
}
public
bool
IsIndexingDisabled
{
get
{
return
disableIndexing; }
}
public
string
PasswordEncodingFormat
{
get
{
return
passwordEncodingFormat; }
}
public
string
UploadFilesPath
{
get
{
return
uploadFilesPath; }
}
public
bool
IsEmailDisabled
{
get
{
return
disableEmail; }
}
public
int
ThreadIntervalEmail
{
get
{
return
threadIntervalEmail; }
}
public
int
ThreadIntervalStats
{
get
{
return
threadIntervalStats; }
}
public
short
SmtpServerConnectionLimit
{
get
{
return
smtpServerConnectionLimit; }
}
public
bool
EnableLatestVersionCheck
{
get
{
return
enableLatestVersionCheck; }
}
#endregion
}
///
<summary>
///
数据提供者实体类
///
</summary>
public
class
Provider
{
#region
成员字段
private
string
name;
private
string
providerType;
private
ExtensionType extensionType;
private
NameValueCollection providerAttributes
=
new
NameValueCollection();
#endregion
#region
构造器
public
Provider(XmlAttributeCollection attributes)
{
//
Set the name of the provider
//
name
=
attributes[
"
name
"
].Value;
//
Set the extension type
//
try
{
extensionType
=
(ExtensionType)Enum.Parse(
typeof
(ExtensionType), attributes[
"
extensionType
"
].Value,
true
);
}
catch
{
//
Occassionally get an exception on parsing the extensiontype, so set it to Unknown
extensionType
=
ExtensionType.Unknown;
}
providerType
=
attributes[
"
type
"
].Value;
//
Store all the attributes in the attributes bucket
//
foreach
(XmlAttribute attribute
in
attributes)
{
if
((attribute.Name
!=
"
name
"
)
&&
(attribute.Name
!=
"
type
"
))
providerAttributes.Add(attribute.Name, attribute.Value);
}
}
#endregion
#region
公有属性
public
string
Name
{
get
{
return
name; }
}
public
string
Type
{
get
{
return
providerType; }
}
public
ExtensionType ExtensionType
{
get
{
return
extensionType; }
}
public
NameValueCollection Attributes
{
get
{
return
providerAttributes; }
}
#endregion
}
}
//
*********************************************************************
//
ForumsConfigurationHandler
//
///
<summary>
///
Class used by ASP.NET Configuration to load ASP.NET Forums configuration.
///
</summary>
///
//
***********************************************************************/
/*
internal class ForumsConfigurationHandler : IConfigurationSectionHandler
{
public virtual object Create(Object parent, Object context, XmlNode node)
{
ForumConfiguration config = new ForumConfiguration();
config.LoadValuesFromConfigurationXml(node);
return config;
}
}
*/
这个配置文件配置了ANF的默认数据提供者、默认语言、论坛路径、是滞禁用后台线程、是滞禁止索引、是否禁止邮件、密码加密格式、线程间隔状态、邮件队列发送间隔、SMTP服务器设置、版本检查
上传文件路径、数据提供者、自定义HttpModule等。主要方法为GetConfig():
代码
public
static
ForumConfiguration GetConfig()
{
ForumConfiguration config
=
cache.Get(CacheKey)
as
ForumConfiguration;
if
(config
==
null
)
{
string
path;
if
(HttpContext.Current
!=
null
)
path
=
HttpContext.Current.Server.MapPath(
"
~/Forums.config
"
);
else
path
=
Directory.GetCurrentDirectory()
+
Path.DirectorySeparatorChar
+
"
Forums.config
"
;
XmlDocument doc
=
new
XmlDocument();
doc.Load(path);
config
=
new
ForumConfiguration(doc);
cache.Insert(CacheKey,config,
new
CacheDependency(path),DateTime.MaxValue,TimeSpan.Zero,CacheItemPriority.AboveNormal,
null
);
//
cache.ReSetFactor(config.CacheFactor);
}
return
config;
}
在此方法中，首先从Cache缓存中获取配置信息，如配置信息还未缓存，则读敢配置文件。配置文件位于网站根目录下的Forums.config文件。读取配置文件的内容后插入缓存中以便下次使用。
Forums.config文件如下：
代码
<?
xml version
=
"
1.0
"
encoding
=
"
utf-8
"
?>
<
Forums
>
<
Core defaultLanguage
=
"
zh-CN
"
forumFilesPath
=
"
/
"
disableEmail
=
"
false
"
disableIndexing
=
"
true
"
disableThreading
=
"
false
"
threadIntervalStats
=
"
15
"
threadIntervalEmail
=
"
15
"
smtpServerConnectionLimit
=
"
-1
"
passwordEncodingFormat
=
"
unicode
"
enableLatestVersionCheck
=
"
false
"
uploadFilesPath
=
"
/Upload/
"
defaultProvider
=
"
SqlForumsProvider
"
>
<
providers
>
<
clear
/>
<
add name
=
"
LocalSqlForumsProvider
"
type
=
"
AspNetForums.Data.SqlDataProvider, AspNetForums.SqlDataProvider
"
connectionString
=
"
server=.;database=Forums;uid=sa;pwd=
"
databaseOwner
=
"
dbo
"
/>
<
add name
=
"
SqlForumsProvider
"
type
=
"
AspNetForums.Data.SqlDataProvider, AspNetForums.SqlDataProvider
"
connectionStringName
=
"
SiteSqlServer
"
databaseOwnerStringName
=
"
SiteSqlServerOwner
"
/>
<
add name
=
"
SqlDataProviderNonDbo
"
type
=
"
AspNetForums.Data.SqlDataProviderNonDbo, AspNetForums.SqlDataProviderNonDbo
"
connectionStringName
=
"
SiteSqlServer
"
databaseOwnerStringName
=
"
SiteSqlServerOwner
"
/>
</
providers
>
<
extensionModules
>
<
add name
=
"
PassportAuthentication
"
extensionType
=
"
Security
"
type
=
"
Telligent.CommunityServer.Security.PassportAuthentication, Telligent.CommunityServer.SecurityModules
"
/>
<
add name
=
"
WindowsAuthentication
"
extensionType
=
"
Security
"
type
=
"
Telligent.CommunityServer.Security.WindowsAuthentication, Telligent.CommunityServer.SecurityModules
"
allowAutoUserRegistration
=
"
true
"
adminWindowsGroup
=
"
Administrators
"
adminWindowsGroupIsSystemAdministrator
=
"
true
"
/>
<
add name
=
"
FormsAuthentication
"
extensionType
=
"
Security
"
type
=
"
Telligent.CommunityServer.Security.FormsAuthentication, Telligent.CommunityServer.SecurityModules
"
allowAutoUserRegistration
=
"
true
"
userEmailAddressCookie
=
"
CSUserEmailAddress
"
useEncryptedEmailAddressCookie
=
"
false
"
/>
</
extensionModules
>
</
Core
>
</
Forums
>
二、缓存
通过在类中添加private static readonly Cache cache = HttpRuntime.Cache;来实现。
三、多数据访问
ANF的数据访问基类是ForumsDataProvider类，ForumsDataProvider这个类位于AspNetForums.Components命名空间下。这是一个抽象类，你可以去实现你的SQL子类或其他子类。主要方法为两个实例化方法。
实例化方法一：
public
static
ForumsDataProvider Instance()
{
//
理论上应该出现不了null,但程序运行确实出现过.原因待查.
if
(_defaultInstance
==
null
)
CreateDefaultCommonProvider();
return
_defaultInstance;
}
在第一个实例化方法中，使用了单例设计模式，如果默认实例为空，则创建默认实例，方法如下：
代码
private
static
void
CreateDefaultCommonProvider()
{
ForumConfiguration config
=
ForumConfiguration.GetConfig();
Provider sqlForumsProvider
=
(Provider) config.Providers[config.DefaultProvider];
_defaultInstance
=
DataProviders.CreateInstance(sqlForumsProvider)
as
ForumsDataProvider;
}
首先获取配置信息，通过配置信息中的默认数据提供者来创建默认实例。
实例化方法二：
代码
public
static
ForumsDataProvider Instance (Provider dataProvider)
{
ForumsDataProvider fdp
=
cache.Get(dataProvider.Name)
as
ForumsDataProvider;
if
(fdp
==
null
)
{
fdp
=
DataProviders.Invoke(dataProvider)
as
ForumsDataProvider;
cache.Insert(dataProvider.Name,fdp,
null
,DateTime.MaxValue,TimeSpan.Zero,CacheItemPriority.AboveNormal,
null
);
}
return
fdp;
}
在第二个实例化方法中，使用了缓存，通过给定的提供者，如果缓存中有，则直接调用。如果没有，则创建。创建后插入缓存以便下次使用。
其它抽象方法为子类需要实现的真正的数据访问方法。
欢迎大家指正。