Spring.Net学习系列一（续）：日志处理
本文接着上篇：Spring.Net学习系列一： 统一异常处理继续学习Spring.Net的AOP。
在这篇中，将利用前置通知(BeforeAdvice),通过.net的Attribute特性来实现日志处理。
在上一篇中，我们通过ProxyFactoryObject显式创建AOP代理的方法。如果应用程序需要创建很多AOP代理，比如当需要代理某个服务层或者数据访问层的所有对象时，这种方法就会使配置文件变的相当庞大。为简化配置过程，Spring.NET提供了“自动代理”的功能，可以根据条件自动创建代理对象，也就是说，可以将多个对象分组以作为要代理的候选对象。在本文中，将使用ObjectNameAutoProxyCreator进行自动代理。ObjectNameAutoProxyCreator可以用特定的文本值或通配符匹配目标对象的名称，并为满足条件的目标对象创建AOP代理。该类支持模式匹配字符串，如："*name"，"name*"，”*name*“和精确文本如"name"。
注：这里的ObjectName即为配置文件中objects节点下的一系列的object的名称
首先创建前置通知的具体实现：
代码
using
System;
using
System.Collections.Generic;
using
System.Text;
using
Spring.Aop;
using
System.Web;
namespace
Log
{
public
class
BeforeAdvice : IMethodBeforeAdvice
{
private
Log logInstance;
public
BeforeAdvice()
{
logInstance
=
Log.GetInstance();
}
public
void
Before(System.Reflection.MethodInfo method,
object
[] args,
object
target)
{
Type dao
=
target.GetType();
Object[] attributes
=
dao.GetMethod(method.Name).GetCustomAttributes(
true
);
OperationAttribute attribute
=
null
;
foreach
(
object
obj
in
attributes)
{
if
(obj
is
OperationAttribute)
{
attribute
=
obj
as
OperationAttribute;
break
;
}
}
if
(attribute
!=
null
)
{
User user
=
HttpContext.Current.Session[
"
user
"
]
as
User;
string
strLogInfo
=
string
.Format(
"
UserName:{0} ,OperationTime:{1},OperationType:{2},OperatedTarget:{3},Method:{4},Argument:{5}
"
,
user.UserName, DateTime.Now, attribute.Op, target, method,ArrayToString(args));
logInstance.Info(strLogInfo);
}
}
private
string
ArrayToString(
object
[] args)
{
if
(args
==
null
||
args.Length
==
0
)
return
"
NULL
"
;
string
str
=
""
;
foreach
(
object
o
in
args)
{
str
+=
o.ToString()
+
"
|
"
;
//
在实体类中，需要重写ToString方法,以获得更好效果
}
return
str.TrimEnd(
new
char
[]{
'
|
'
});
}
}
}
接下来模拟一个数据访问层IUserDao和实现类
代码
using
System;
using
System.Collections.Generic;
using
System.Text;
namespace
Log
{
public
interface
IUserDao
{
IList
<
User
>
GetUserByName(
string
userName,
string
password);
void
SaveUser(User u);
void
UpdateUser(User u);
void
DeleteUser(User u);
}
}
代码
using
System;
using
System.Collections.Generic;
using
System.Linq;
using
System.Text;
namespace
Log
{
public
class
UserDao:IUserDao
{
#region
IUserDao 成员
[Operation(OperationEnum.Select)]
public
IList
<
User
>
GetUserByName(
string
userName,
string
password)
{
return
null
;
}
[Operation(OperationEnum.Insert)]
public
void
SaveUser(User u)
{
}
[Operation(OperationEnum.Update)]
public
void
UpdateUser(User u)
{
}
[Operation(OperationEnum.Delete)]
public
void
DeleteUser(User u)
{
}
#endregion
}
}
注意在UserDao实现类中已经加入了OperationAttribute。
OperationAttribute的代码如下：
代码
using
System;
using
System.Collections.Generic;
using
System.Text;
namespace
Log
{
[AttributeUsage(AttributeTargets.Class
|
AttributeTargets.Method
|
AttributeTargets.Property, Inherited
=
true
)]
public
class
OperationAttribute:Attribute
{
private
OperationEnum op;
public
OperationAttribute(OperationEnum op)
{
this
.op
=
op;
}
public
OperationEnum Op
{
get
{
return
this
.op; }
}
}
}
OperationEnum枚举类中定义了一些操作
代码
using
System;
using
System.Collections.Generic;
using
System.Text;
namespace
Log
{
public
enum
OperationEnum
{
Select,
Insert,
Update,
Delete
}
}
接下来就是配置Spring的AOP了
代码
<?
xml version
=
"
1.0
"
encoding
=
"
utf-8
"
?>
<
objects xmlns
=
"
http://www.springframework.net
"
xmlns:xsi
=
"
http://www.w3.org/2001/XMLSchema-instance
"
xsi:schemaLocation
=
"
http://www.springframework.net
http:
//
www.springframework.net/xsd/spring-objects.xsd">
<
object
id
=
"
UserDao
"
type
=
"
Log.UserDao, Log
"
/>
<!--
Advice
-->
<
object
id
=
"
LogAdvice
"
type
=
"
Log.BeforeAdvice, Log
"
/>
<
object
id
=
"
autoLogProxyCreator
"
type
=
"
Spring.Aop.Framework.AutoProxy.ObjectNameAutoProxyCreator, Spring.Aop
"
>
<
property name
=
"
ObjectNames
"
>
<
list
>
<
value
>*
Dao
</
value
>
</
list
>
</
property
>
<
property name
=
"
InterceptorNames
"
>
<
list
>
<
value
>
LogAdvice
</
value
>
</
list
>
</
property
>
</
object
>
</
objects
>
构建测试页面：
代码
using
System;
using
System.Configuration;
using
System.Data;
using
System.Linq;
using
System.Web;
using
System.Web.Security;
using
System.Web.UI;
using
System.Web.UI.HtmlControls;
using
System.Web.UI.WebControls;
using
System.Web.UI.WebControls.WebParts;
using
Spring.Context;
using
Spring.Context.Support;
using
Log;
public
partial
class
_Default : System.Web.UI.Page
{
private
IApplicationContext _ctx;
private
IUserDao _userDao;
protected
void
Page_Load(
object
sender, EventArgs e)
{
User u
=
new
User();
u.UserName
=
"
huihui
"
;
u.Password
=
"
HUIHUI
"
;
Session[
"
user
"
]
=
u;
userDao.DeleteUser(u);
userDao.GetUserByName(u.UserName, u.Password);
}
private
IApplicationContext ctx
{
get
{
if
(_ctx
==
null
)
{
_ctx
=
ContextRegistry.GetContext();
}
return
_ctx;
}
}
private
IUserDao userDao
{
get
{
if
(_userDao
==
null
)
{
_userDao
=
ctx[
"
UserDao
"
]
as
IUserDao;
}
return
_userDao;
}
}
}
运行可以看到日志中已经记录如下内容：
2009-12-14 23:39:46,890 [4] INFO AppLog [(null)] - UserName:huihui ,OperationTime:2009-12-14 23:39:46,OperationType:Delete,OperatedTarget:Log.UserDao,Method:Void DeleteUser(Log.User),Argument:Log.User
2009-12-14 23:39:46,921 [4] INFO AppLog [(null)] - UserName:huihui ,OperationTime:2009-12-14 23:39:46,OperationType:Select,OperatedTarget:Log.UserDao,Method:System.Collections.Generic.IList`1[Log.User] GetUserByName(System.String, System.String),Argument:huihui|HUIHUI
日志输出格式可以根据项目需要自行调整，如果需要给管理员（针对用户）看日志，很明显上面的输出可能不太合适，这就需要对此进行一些调整。比如UserDao映射到“用户信息表”等等。