SprinMVC中自定义拦截器

迷南。 2022-08-06 04:16 140阅读 0赞

一，首先介绍springMVC中的拦截器

[Spring MVC 拦截器][Spring MVC]

Controller层的拦截器继承于HandlerInterceptorAdapter  
  
HandlerInterceptorAdapter.java

1  public   abstract   class  HandlerInterceptorAdapter  implements  HandlerInterceptor \{  
  2    
  3       /\*\*   
  4       \* This implementation always returns <code>true</code>.  
  5        \*/   
  6       public   boolean  preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)  
  7           throws  Exception \{  
  8           return   true ;  
  9      \}  
 10    
 11       /\*\*   
 12       \* This implementation is empty.  
 13        \*/   
 14       public   void  postHandle(  
 15              HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView)  
 16               throws  Exception \{  
 17      \}  
 18    
 19       /\*\*   
 20       \* This implementation is empty.  
 21        \*/   
 22       public   void  afterCompletion(  
 23              HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)  
 24               throws  Exception \{  
 25      \}  
 26    
 27  \}

Spring拦截器通过重写这三个方法实现Controller的拦截。

配置拦截器  
xml

1  < bean id = " handlerMapping "   
  2             class = " org.springframework.web.servlet.handler.SimpleUrlHandlerMapping " >   
  3           < property name = " interceptors " >   
  4               < list >   
  5                   < ref bean = " controllerInterceptor "   />   
  6               </ list >   
  7           </ property >   
  8           < property name = " mappings " >   
  9               < props >   
 10                   < prop key = " /hao/hello.do " > helloWorldController </ prop >   
 11               </ props >   
 12           </ property >   
 13       </ bean >   
 14        
 15       < bean id = " controllerInterceptor "   class = " com.web.spring.mvc.interceptor.ControllerInterceptor " />   
 16

ControllerInterceptor.java

1  public   class  ControllerInterceptor  extends  HandlerInterceptorAdapter \{  
  2    
  3       /\*\*   
  4       \* 在Controller方法前进行拦截  
  5        \*/   
  6       public   boolean  preHandle(HttpServletRequest request,  
  7              HttpServletResponse response, Object handler)  throws  Exception \{  
  8          System.out.println( " ControllerInterceptor.preHandle() " );  
  9           return   true ;  
 10      \}  
 11    
 12       /\*\*   
 13       \* This implementation is empty.  
 14        \*/   
 15       public   void  postHandle(HttpServletRequest request,  
 16              HttpServletResponse response, Object handler,  
 17              ModelAndView modelAndView)  throws  Exception \{  
 18          System.out.println( " ControllerInterceptor.postHandle() " );  
 19      \}  
 20    
 21       /\*\*   
 22       \* 在Controller方法后进行拦截  
 23        \*/   
 24       public   void  afterCompletion(HttpServletRequest request,  
 25              HttpServletResponse response, Object handler, Exception ex)  
 26               throws  Exception \{  
 27          System.out.println( " ControllerInterceptor.afterCompletion() " );  
 28      \}  
 29 \}

说明：  
发起请求,进入拦截器链，运行所有拦截器的preHandle方法，  
1.当preHandle方法返回false时，从当前拦截器往回执行所有拦截器的afterCompletion方法，再退出拦截器链。  
2.当preHandle方法全为true时，执行下一个拦截器,直到所有拦截器执行完。再运行被拦截的Controller。然后进入拦截器链，

运行所有拦截器的postHandle方法,完后从最后一个拦截器往回执行所有拦截器的afterCompletion方法.  
当有拦截器抛出异常时,会从当前拦截器往回执行所有拦截器的afterCompletion方法

Controller

1    
  2  @Controller  
  3  @RequestMapping( " /hao " )   
  5  public   class  HelloWorldController \{  
  6    
  7      @RequestMapping(value  =   " /hello " )  
  8       public  String hello(HttpServletRequest request, HttpServletResponse response) \{  
  9          System.out.println( " hello " );   
 15           return   " helloWorld " ;  
 16      \}  
 17  \}

**二，springMVC中拦截器的执行顺序**

我在mvc-servlet.xml中放入了两个拦截器

**\[html\]**  [view plain][] [copy][view plain]

1.    
2.      **<****mvc:interceptors****>**  
3.          **<****mvc:interceptor****>**  
4.              **<****mvc:mapping** path="/\*\*" **/>**  
5.              **<****bean** class="com.wendellup.web.base.annotation.method.security.SystemCommonInterceptor"**>**  
6.                  **<****property** name="moreThanTime"**>**  
7.                      **<****value****>**500**</****value****>**  
8.                  **</****property****>**  
9.              **</****bean****>**  
10.         **</****mvc:interceptor****>**  
11.         **<****mvc:interceptor****>**  
12.             **<****mvc:mapping** path="/\*\*" **/>**  
13.             **<****bean**  
14.                 class="com.wendellup.web.base.annotation.method.business.AnnotationBusinessDescInterceptor"**>**  
15.             **</****bean****>**  
16.         **</****mvc:interceptor****>**  
17.     **</****mvc:interceptors****>**

并在这两个拦截器中preHandle,postHandle,afterCompletion中和controller中添加测试语句

启动服务器访问tomcat后控制台的代码如下:

**\[html\]**  [view plain][] [copy][view plain]

1.  \[INFO \] 2013-01-22 15:55:23 :SystemCommonInterceptor: preHandle  
2.  \[INFO \] 2013-01-22 15:55:23 :AnnotationBusinessDescInterceptor: preHandle  
3.  \[INFO \] 2013-01-22 15:55:23 :------------LoginController------------  
4.  \[INFO \] 2013-01-22 15:55:23 :AnnotationBusinessDescInterceptor: postHandle  
5.  \[INFO \] 2013-01-22 15:55:23 :SystemCommonInterceptor: postHandle  
6.  \[INFO \] 2013-01-22 15:55:23 :AnnotationBusinessDescInterceptor: afterCompletion  
7.  \[INFO \] 2013-01-22 15:55:23 :SystemCommonInterceptor: afterCompletion

**三，springMVC中拦截器的应用**

1.一次请求所花费的时间

2.某个controller需要登录才能访问

3.springMVC实现动态国际化

4.某个方法必须加自定义的注释

[Spring MVC]: http://www.blogjava.net/wmcoo/articles/333752.html
[view plain]: http://blog.csdn.net/wendellup/article/details/8528376#