struts2 -- interceptor(如何配置Interceptor)

1.interceptor的配置

方法1. 普通配置法

1. <struts>
2.     <package name="struts2" extends="struts-default">
3.         <interceptors>
4.             <interceptor name="myInterceptor" class="edu.hust.interceptor.MyInterceptor">interceptor>
5.         interceptors>
7.         <action name="register" class="edu.hust.action.RegisterAction">
8.             <result name="input">/register.jspresult>
9.             <result>/result.jspresult>
10.             
11.             
12.             
13.             <interceptor-ref name="defaultStack">interceptor-ref>
14.             <interceptor-ref name="myInterceptor">interceptor-ref>
15.         action>
16.     package>
17. struts>

方法2. 配置拦截器栈(即将多个interceptor串联的一种元素)。然后在中引入该拦截器栈就可以了。

1. <struts>
2.     <package name="struts2" extends="struts-default">
3.         
4.         <interceptors>
5.             <interceptor name="myInterceptor" class="edu.hust.interceptor.MyInterceptor">interceptor>
6.         
7.             <interceptor-stack name="myInterceptorStack">
8.                 <interceptor-ref name="myInterceptor">interceptor-ref>
9.                 <interceptor-ref name="defaultStack">interceptor-ref>
10.             interceptor-stack>
11.         interceptors>
12.         
13.         <action name="register" class="edu.hust.action.RegisterAction">
14.             <result name="input">/register.jspresult>
15.             <result>/result.jspresult>
16.             
17.             <interceptor-ref name="myInterceptorStack">interceptor-ref>
18.         action>
19.     package>
20. struts>

方法3. 修改默认拦截器，将自定义的拦截器栈定义为struts2的默认拦截器。

1. <struts>
2.     <package name="struts2" extends="struts-default">
3.         
4.         <interceptors>
5.             <interceptor name="myInterceptor" class="edu.hust.interceptor.MyInterceptor">interceptor>
6.             <interceptor-stack name="myInterceptorStack">
7.                 <interceptor-ref name="myInterceptor">interceptor-ref>
8.                 <interceptor-ref name="defaultStack">interceptor-ref>
9.             interceptor-stack>
10.         interceptors>
12.         
13.         
14.         <default-interceptor-ref name="myInterceptorStack">default-interceptor-ref>
15.         
16.         <action name="register" class="edu.hust.action.RegisterAction">
17.             <result name="input">/register.jspresult>
18.             <result>/result.jspresult>
19.         action>
20.         
21.     package>
22. struts>

2. Interceptor的角色对象

(1)拦截目标对象(被代理对象)，这里目标对象就是action；

(2)拦截器(一个类，动态的将某些方法插入到目标对象的某方法的before、after)；

(3)对目标对象生成的(动态)代理对象(代理对象内部方法综合了目标对象方法+拦截器方法)。程序最终执行的是目标对象的代理，而这个代理已经插入了interceptor。

拦截器作用：拦截action。interceptor相当于一个入口和出口，通过interceptor进入action，执行完action的代码再通过interceptor出去。

针对"struts2 -- interceptor(Interceptor怎么写)"这篇文章的MyInterceptor.class和MyInterceptor2.class。根据下面的配置文件执行程序

1. <struts>
2.     <package name="struts2" extends="struts-default">
3.         
4.         <interceptors>
5.             <interceptor name="myInterceptor" class="edu.hust.interceptor.MyInterceptor">interceptor>
6.             <interceptor name="myInterceptor2" class="edu.hust.interceptor.MyInterceptor2">interceptor>
7.             <interceptor-stack name="myInterceptorStack">
8.                 <interceptor-ref name="myInterceptor">interceptor-ref>
9.                 <interceptor-ref name="myInterceptor2">interceptor-ref>
10.                 <interceptor-ref name="defaultStack">interceptor-ref>
11.             interceptor-stack>
12.         interceptors>
13.         
14.         <default-interceptor-ref name="myInterceptorStack">default-interceptor-ref>
15.         
16.         <action name="register" class="edu.hust.action.RegisterAction">
17.             <result name="input">/register.jspresult>
18.             <result>/result.jspresult>
19.         action>
20.         
21.     package>
22. struts>

Console会得到以下打印输出
intercept start
intercept2 start
2008-9-19 19:42:06 com.opensymphony.xwork2.validator.ActionValidatorManagerFactory
信息: Detected AnnotationActionValidatorManager, initializing it...
intercept2 finish
intercept finish

这个结果解释了"interceptor相当于一个入口和出口，通过interceptor进入action，执行完action的代码再通过interceptor出去"这句话。

3. extends MethodFilterInterceptor的拦截器如何配置哪些方法该拦截、哪些方法不该拦截(针对方法拦截的配置)

1. <struts>
2.     <package name="struts2" extends="struts-default">
3.         
4.         <interceptors>
5.             <interceptor name="myInterceptor3" class="edu.hust.interceptor.MyInterceptor3">interceptor>
6.         interceptors>
7.         
8.         <action name="register" class="edu.hust.action.RegisterAction" method="queryAll">
9.             <result name="input">/register.jspresult>
10.             <result>/result.jspresult>
11.             
12.             <interceptor-ref name="myInterceptor3">
13.                 <param name="includeMethods">queryAll, executeparam>
14.             interceptor-ref>
15.             <interceptor-ref name="defaultStack">interceptor-ref>
16.         action>
17.         
18.         <action name="register" class="edu.hust.action.RegisterAction" method="insert">
19.             <result name="input">/register.jspresult>
20.             <result>/result.jspresult>
21.             <interceptor-ref name="myInterceptor3">
22.                 <param name="includeMethods">queryAll, insertparam>
23.             interceptor-ref>
24.             <interceptor-ref name="defaultStack">interceptor-ref>
25.         action>
26.         
27.         <action name="register" class="edu.hust.action.RegisterAction" method="update">
28.             <result name="input">/register.jspresult>
29.             <result>/result.jspresult>
30.             <interceptor-ref name="myInterceptor3">
31.                 <param name="includeMethods">queryAll, insertparam>
32.             interceptor-ref>
33.             <interceptor-ref name="defaultStack">interceptor-ref>
34.         action>
35.         
36.     package>
37. struts>