Spring拦截器

Spring Interceptors具备前处理和后处理web请求的能力，每一个拦截器类应当继承HandlerInterceptorAdapter类，你可以覆写任意preHandle（），postHandle（）或afterCompletion（）这三个回调方法。正如这个名字一样preHandler（）方法会在处理请求之前被调用，postHandle（）方法会在处理请求之后调用，而afterCompletion（）将会在显示视图后被调用。
在每个方法里我们将使用log4j记录日志信息，首先应该实例化一个静态日志记录器，然后建立基本配置使得日志信息能显示在控制台。
LoggerInterceptor 类如下：
[java] view plaincopy
package com.zcl.spring.interceptor;  
  
import javax.servlet.http.HttpServletRequest;  
import javax.servlet.http.HttpServletResponse;  
  
import org.apache.log4j.BasicConfigurator;  
import org.apache.log4j.Logger;  
import org.springframework.web.servlet.ModelAndView;  
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;  
  
public class LoggerInterceptor extends HandlerInterceptorAdapter {  
    static Logger logger = Logger.getLogger(LoggerInterceptor.class) ;  
    static{  
        BasicConfigurator.configure() ;  
    }  
      
    @Override  
    public boolean preHandle(HttpServletRequest request,HttpServletResponse response, Object handler) throws Exception{  
        logger.info("Before handling the request") ;  
        return super.preHandle(request, response, handler) ;  
    }  
      
    @Override  
    public void postHandle(HttpServletRequest request,HttpServletResponse response,Object handler,ModelAndView modelAndView) throws Exception{  
        logger.info("After handling the request") ;  
        super.postHandle(request, response, handler, modelAndView) ;  
    }  
      
    @Override  
    public void afterCompletion(HttpServletRequest request,HttpServletResponse response,Object handler,Exception ex) throws Exception{  
        logger.info("After rendering the view") ;  
        super.afterCompletion(request, response, handler, ex) ;  
    }  
}  


现在你需要关联你已经创建的logger拦截器到映射处理，这里我们使用BeanNameUrlHandlerMapping，假如你需要的不止一个映射处理那么你需要将拦截器和它们每一个相关联。下面的配置即是如何关联拦截器到映射处理。
[html] view plaincopy
<?xml version="1.0" encoding="UTF-8"?>  
<beans xsi:schemaLocation="http://www.springframework.org/schema/beans   
http://www.springframework.org/schema/beans/spring-beans.xsd  
http://www.springframework.org/schema/context  
http://www.springframework.org/schema/context/spring-context.xsd"  
xmlns:context="http://www.springframework.org/schema/context"   
xmlns:p="http://www.springframework.org/schema/p"   
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   
xmlns="http://www.springframework.org/schema/beans">   
    <bean id="viewResolver"  
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">  
        <property name="prefix">  
            <value>/WEB-INF/jsp/</value>  
        </property>  
        <property name="suffix">  
            <value>.jsp</value>  
        </property>  
    </bean>  
    <!--<bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource"   
        p:basename="message" />-->  
    <bean id="handlerMapping" class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping" p:interceptors-ref="loggerInterceptor" />  
    <bean id="loggerInterceptor" class="com.zcl.spring.interceptor.LoggerInterceptor" />  
    <!--<context:component-scan base-package="com.zcl.spring.validation" />-->  
    <bean id="userService" class="com.zcl.spring.validation.UserServiceImpl" />  
    <!-- <bean id="userValidator" class="com.zcl.spring.validation.UserValidator" />-->  
    <bean name="/userRegistration.html" class="com.zcl.spring.validation.UserController"  
            p:userService-ref="userService" p:formView="userForm"   
            p:successView="userSuccess" />  
</beans>  
这里我们也要注意一下UserController如下：
[java] view plaincopy
import org.springframework.web.servlet.ModelAndView;  
import org.springframework.web.servlet.mvc.SimpleFormController;  
  
  
@SuppressWarnings("deprecation")  
public class UserController extends SimpleFormController {  
    private UserService userService ;  
    public UserController(){  
        setCommandClass(User.class) ;  
        setCommandName("user") ;  
    }  
    public void setUserService(UserService userService){  
        this.userService = userService ;  
    }  
    @Override  
    protected ModelAndView onSubmit(Object command) throws Exception{  
        User user = (User)command ;  
        userService.add(user) ;  
        return new ModelAndView("userSuccess","user",user) ;  
    }  
}  


运行后我们会在控制台看到如下信息：
[plain] view plaincopy
<span style="font-family:'Courier New', Courier, monospace;font-size:16px;"><span style="line-height: 1.5;">51242 [http-8888-2] DEBUG org.springframework.web.servlet.DispatcherServlet  - DispatcherServlet with name 'dispatcher' determining Last-Modified value for [/spring3/userRegistration.html]  
51243 [http-8888-2] DEBUG org.springframework.web.servlet.DispatcherServlet  - Testing handler map [org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping@116aeb] in DispatcherServlet with name 'dispatcher'  
51248 [http-8888-2] DEBUG org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping  - Mapping [/userRegistration.html] to handler 'com.zcl.spring.validation.UserController@1e13ce3'  
51248 [http-8888-2] DEBUG org.springframework.web.servlet.DispatcherServlet  - Testing handler adapter [org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter@1be9101]  
51251 [http-8888-2] DEBUG org.springframework.web.servlet.DispatcherServlet  - Testing handler adapter [org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter@ce4dda]  
51253 [http-8888-2] DEBUG org.springframework.web.servlet.DispatcherServlet  - Last-Modified value for [/spring3/userRegistration.html] is: -1  
51276 [http-8888-2] DEBUG org.springframework.web.servlet.DispatcherServlet  - Bound request context to thread: org.apache.catalina.connector.RequestFacade@6ea9d2  
51276 [http-8888-2] DEBUG org.springframework.web.servlet.DispatcherServlet  - DispatcherServlet with name 'dispatcher' processing GET request for [/spring3/userRegistration.html]  
51280 [http-8888-2] INFO com.zcl.spring.interceptor.LoggerInterceptor  - Before handling the request  
51280 [http-8888-2] DEBUG org.springframework.web.servlet.DispatcherServlet  - Testing handler adapter [org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter@1be9101]  
51280 [http-8888-2] DEBUG org.springframework.web.servlet.DispatcherServlet  - Testing handler adapter [org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter@ce4dda]  
51280 [http-8888-2] DEBUG com.zcl.spring.validation.UserController  - Displaying new form  
51281 [http-8888-2] DEBUG com.zcl.spring.validation.UserController  - Creating new command of class [com.zcl.spring.validation.User]  
51312 [http-8888-2] INFO com.zcl.spring.interceptor.LoggerInterceptor  - After handling the request  
51318 [http-8888-2] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory  - Invoking afterPropertiesSet() on bean with name 'userForm'  
51318 [http-8888-2] DEBUG org.springframework.web.servlet.view.InternalResourceViewResolver  - Cached view [userForm]  
51318 [http-8888-2] DEBUG org.springframework.web.servlet.DispatcherServlet  - Rendering view [org.springframework.web.servlet.view.JstlView: name 'userForm'; URL [/WEB-INF/jsp/userForm.jsp]] in DispatcherServlet with name 'dispatcher'  
51318 [http-8888-2] DEBUG org.springframework.web.servlet.view.JstlView  - Rendering view with name 'userForm' with model {org.springframework.validation.BindingResult.user=org.springframework.validation.BeanPropertyBindingResult: 0 errors, user=com.zcl.spring.validation.User@c26acd} and static attributes {}  
51319 [http-8888-2] DEBUG org.springframework.web.servlet.view.JstlView  - Added model object 'user' of type [com.zcl.spring.validation.User] to request in view with name 'userForm'  
51319 [http-8888-2] DEBUG org.springframework.web.servlet.view.JstlView  - Added model object 'org.springframework.validation.BindingResult.user' of type [org.springframework.validation.BeanPropertyBindingResult] to request in view with name 'userForm'  
51378 [http-8888-2] DEBUG org.springframework.web.servlet.view.JstlView  - Forwarding to resource [/WEB-INF/jsp/userForm.jsp] in InternalResourceView 'userForm'  
53139 [http-8888-2] DEBUG org.springframework.beans.CachedIntrospectionResults  - Getting BeanInfo for class [com.zcl.spring.validation.User]  
53144 [http-8888-2] DEBUG org.springframework.beans.CachedIntrospectionResults  - Caching PropertyDescriptors for class [com.zcl.spring.validation.User]  
53144 [http-8888-2] DEBUG org.springframework.beans.CachedIntrospectionResults  - Found bean property 'aboutYou' of type [java.lang.String]  
53144 [http-8888-2] DEBUG org.springframework.beans.CachedIntrospectionResults  - Found bean property 'class' of type [java.lang.Class]  
53144 [http-8888-2] DEBUG org.springframework.beans.CachedIntrospectionResults  - Found bean property 'community' of type [[Ljava.lang.String;]  
53144 [http-8888-2] DEBUG org.springframework.beans.CachedIntrospectionResults  - Found bean property 'country' of type [java.lang.String]  
53144 [http-8888-2] DEBUG org.springframework.beans.CachedIntrospectionResults  - Found bean property 'gender' of type [java.lang.String]  
53144 [http-8888-2] DEBUG org.springframework.beans.CachedIntrospectionResults  - Found bean property 'mailingList' of type [boolean]  
53144 [http-8888-2] DEBUG org.springframework.beans.CachedIntrospectionResults  - Found bean property 'name' of type [java.lang.String]  
53144 [http-8888-2] DEBUG org.springframework.beans.CachedIntrospectionResults  - Found bean property 'password' of type [java.lang.String]  
53146 [http-8888-2] DEBUG org.springframework.beans.BeanUtils  - No property editor [java.lang.StringEditor] found for type java.lang.String according to 'Editor' suffix convention  
53157 [http-8888-2] DEBUG org.springframework.beans.BeanUtils  - No property editor [booleanEditor] found for type boolean according to 'Editor' suffix convention  
53157 [http-8888-2] INFO com.zcl.spring.interceptor.LoggerInterceptor  - After rendering the view  
53158 [http-8888-2] DEBUG org.springframework.web.servlet.DispatcherServlet  - Cleared thread-bound request context: org.apache.catalina.connector.RequestFacade@6ea9d2  
53158 [http-8888-2] DEBUG org.springframework.web.servlet.DispatcherServlet  - Successfully completed request  
53158 [http-8888-2] DEBUG org.springframework.web.context.support.XmlWebApplicationContext  - Publishing event in context [org.springframework.web.context.support.XmlWebApplicationContext@d7c6bf]: ServletRequestHandledEvent: url=[/spring3/userRegistration.html]; client=[0:0:0:0:0:0:0:1]; method=[GET]; servlet=[dispatcher]; session=[388885EBAC9B01B2FB0DC28FE9EBDCDD]; user=[null]; time=[1905ms]; status=[OK]  
75058 [http-8888-2] DEBUG org.springframework.web.servlet.DispatcherServlet  - Bound request context to thread: org.apache.catalina.connector.RequestFacade@6145c5  
75058 [http-8888-2] DEBUG org.springframework.web.servlet.DispatcherServlet  - DispatcherServlet with name 'dispatcher' processing POST request for [/spring3/userRegistration.html]  
75059 [http-8888-2] DEBUG org.springframework.web.servlet.DispatcherServlet  - Testing handler map [org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping@116aeb] in DispatcherServlet with name 'dispatcher'  
75059 [http-8888-2] DEBUG org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping  - Mapping [/userRegistration.html] to handler 'com.zcl.spring.validation.UserController@1e13ce3'  
75059 [http-8888-2] INFO com.zcl.spring.interceptor.LoggerInterceptor  - </span></span><span style="color:#ff0000;font-family: 'Courier New', Courier, monospace; font-size: 10pt; line-height: 1.5; ">Before handling the request</span><span style="font-family:'Courier New', Courier, monospace;font-size:16px;"><span style="line-height: 1.5;">  
75059 [http-8888-2] DEBUG org.springframework.web.servlet.DispatcherServlet  - Testing handler adapter [org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter@1be9101]  
75059 [http-8888-2] DEBUG org.springframework.web.servlet.DispatcherServlet  - Testing handler adapter [org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter@ce4dda]  
75059 [http-8888-2] DEBUG com.zcl.spring.validation.UserController  - Creating new command of class [com.zcl.spring.validation.User]  
75064 [http-8888-2] DEBUG org.springframework.beans.TypeConverterDelegate  - Converting String to [boolean] using property editor [org.springframework.beans.propertyeditors.CustomBooleanEditor@1d1f3f2]  
75065 [http-8888-2] DEBUG com.zcl.spring.validation.UserController  - No errors -> processing submit  
</span></span><span style="color:#ff0000;font-family: 'Courier New', Courier, monospace; font-size: 10pt; line-height: 1.5; ">User add Success</span><span style="font-family:'Courier New', Courier, monospace;font-size:16px;"><span style="line-height: 1.5;">  
75065 [http-8888-2] INFO com.zcl.spring.interceptor.LoggerInterceptor  - </span></span><span style="color:#ff0000;font-family: 'Courier New', Courier, monospace; font-size: 10pt; line-height: 1.5; ">After handling the request</span><span style="font-family:'Courier New', Courier, monospace;font-size:16px;"><span style="line-height: 1.5;">  
75065 [http-8888-2] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory  - Invoking afterPropertiesSet() on bean with name 'userSuccess'  
75065 [http-8888-2] DEBUG org.springframework.web.servlet.view.InternalResourceViewResolver  - Cached view [userSuccess]  
75065 [http-8888-2] DEBUG org.springframework.web.servlet.DispatcherServlet  - Rendering view [org.springframework.web.servlet.view.JstlView: name 'userSuccess'; URL [/WEB-INF/jsp/userSuccess.jsp]] in DispatcherServlet with name 'dispatcher'  
75065 [http-8888-2] DEBUG org.springframework.web.servlet.view.JstlView  - Rendering view with name 'userSuccess' with model {user=com.zcl.spring.validation.User@e6a73d} and static attributes {}  
75065 [http-8888-2] DEBUG org.springframework.web.servlet.view.JstlView  - Added model object 'user' of type [com.zcl.spring.validation.User] to request in view with name 'userSuccess'  
75065 [http-8888-2] DEBUG org.springframework.web.servlet.view.JstlView  - Forwarding to resource [/WEB-INF/jsp/userSuccess.jsp] in InternalResourceView 'userSuccess'  
75369 [http-8888-2] INFO com.zcl.spring.interceptor.LoggerInterceptor  - </span></span><span style="color:#ff0000;font-family: 'Courier New', Courier, monospace; font-size: 10pt; line-height: 1.5; ">After rendering the view</span><span style="font-family:'Courier New', Courier, monospace;"><span style="font-size:16px;"><span style="line-height: 1.5;">  
75369 [http-8888-2] DEBUG org.springframework.web.servlet.DispatcherServlet  - Cleared thread-bound request context: org.apache.catalina.connector.RequestFacade@6145c5  
75369 [http-8888-2] DEBUG org.springframework.web.servlet.DispatcherServlet  - Successfully completed request</span></span>  
75370 [http-8888-2] DEBUG org.springframework.web.context.support.XmlWebApplicationContext  - Publishing event in context [org.springframework.web.context.support.XmlWebApplicationContext@d7c6bf]: ServletRequestHandledEvent: url=[/spring3/userRegistration.html]; client=[0:0:0:0:0:0:0:1]; method=[POST]; servlet=[dispatcher]; session=[388885EBAC9B01B2FB0DC28FE9EBDCDD]; user=[null]; time=[311ms]; status=[OK]</span>  
上即是记录的日志信息
如果我们要使用annotation，我们需要修改下UserController和配置文件。