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Spring MVC 中 HandlerInterceptorAdapter过滤器的使用
一般情況下,對(duì)來(lái)自瀏覽器的請(qǐng)求的攔截,是利用Filter實(shí)現(xiàn)的,這種方式可以實(shí)現(xiàn)Bean預(yù)處理、后處理。?
Spring MVC的攔截器不僅可實(shí)現(xiàn)Filter的所有功能,還可以更精確的控制攔截精度。?
Spring為我們提供了org.springframework.web.servlet.handler.HandlerInterceptorAdapter這個(gè)適配器,繼承此類,可以非常方便的實(shí)現(xiàn)自己的攔截器。他有三個(gè)方法:
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一般情況下,對(duì)來(lái)自瀏覽器的請(qǐng)求的攔截,是利用Filter實(shí)現(xiàn)的,這種方式可以實(shí)現(xiàn)Bean預(yù)處理、后處理。 Spring MVC的攔截器不僅可實(shí)現(xiàn)Filter的所有功能,還可以更精確的控制攔截精度。 Spring為我們提供了org.springframework.web.servlet.handler.HandlerInterceptorAdapter這個(gè)適配器,繼承此類,可以非常方便的實(shí)現(xiàn)自己的攔截器。他有三個(gè)方法:?
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public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { return true; } public void postHandle( HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception { } public void afterCompletion( HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception { }?
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分別實(shí)現(xiàn)預(yù)處理、后處理(調(diào)用了Service并返回ModelAndView,但未進(jìn)行頁(yè)面渲染)、返回處理(已經(jīng)渲染了頁(yè)面)?
在preHandle中,可以進(jìn)行編碼、安全控制等處理;?
在postHandle中,有機(jī)會(huì)修改ModelAndView;?
在afterCompletion中,可以根據(jù)ex是否為null判斷是否發(fā)生了異常,進(jìn)行日志記錄。?
如果基于xml配置使用Spring MVC,
可以利用SimpleUrlHandlerMapping、BeanNameUrlHandlerMapping進(jìn)行Url映射(相當(dāng)于struts的path映射)和攔截請(qǐng)求(注入interceptors),
如果基于注解使用Spring MVC,可以使用DefaultAnnotationHandlerMapping注入interceptors。
注意無(wú)論基于xml還是基于注解,HandlerMapping bean都是需要在xml中配置的。?
一個(gè)demo:?
在這個(gè)例子中,我們假設(shè)UserController中的注冊(cè)操作只在9:00-12:00開放,那么就可以使用攔截器實(shí)現(xiàn)這個(gè)功能。?
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public class TimeBasedAccessInterceptor extends HandlerInterceptorAdapter { private int openingTime; private int closingTime; private String mappingURL;//利用正則映射到需要攔截的路徑 public void setOpeningTime(int openingTime) { this.openingTime = openingTime; } public void setClosingTime(int closingTime) { this.closingTime = closingTime; } public void setMappingURL(String mappingURL) { this.mappingURL = mappingURL; } @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { String url=request.getRequestURL().toString(); if(mappingURL==null || url.matches(mappingURL)){ Calendar c=Calendar.getInstance(); c.setTime(new Date()); int now=c.get(Calendar.HOUR_OF_DAY); if(now<openingTime || now>closingTime){ request.setAttribute("msg", "注冊(cè)開放時(shí)間:9:00-12:00"); request.getRequestDispatcher("/msg.jsp").forward(request, response); return false; } return true; } return true; } }xml配置:
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<bean id="timeBasedAccessInterceptor" class="com.spring.handler.TimeBasedAccessInterceptor"> <property name="openingTime" value="9" /> <property name="closingTime" value="12" /> <property name="mappingURL" value=".*/user\.do\?action=reg.*" /> </bean> <bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping"> <property name="interceptors"> <list> <ref bean="timeBasedAccessInterceptor"/> </list> </property> </bean>
這里我們定義了一個(gè)mappingURL屬性,實(shí)現(xiàn)利用正則表達(dá)式對(duì)url進(jìn)行匹配,從而更細(xì)粒度的進(jìn)行攔截。當(dāng)然如果不定義mappingURL,則默認(rèn)攔截所有對(duì)Controller的請(qǐng)求。?
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UserController:
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@Controller @RequestMapping("/user.do") public class UserController{ @Autowired private UserService userService; @RequestMapping(params="action=reg") public ModelAndView reg(Users user) throws Exception { userService.addUser(user); return new ModelAndView("profile","user",user); } // other option ... }這個(gè)Controller相當(dāng)于Struts的DispatchAction?
你也可以配置多個(gè)攔截器,每個(gè)攔截器進(jìn)行不同的分工.?
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我們項(xiàng)目里面的例子
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package com.shishuo.studio.filter;import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse;import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; import org.springframework.web.servlet.HandlerInterceptor; import org.springframework.web.servlet.ModelAndView;import com.shishuo.studio.entity.User; import com.shishuo.studio.exception.CookieNotFoundException; import com.shishuo.studio.service.UserService; import com.shishuo.studio.util.CookieUtils;/*** @author Herbert 攔截器的實(shí)現(xiàn)*/ @Component public class AuthInterceptor implements HandlerInterceptor {@Autowiredprivate UserService userService;public void afterCompletion(HttpServletRequest request,HttpServletResponse respone, Object object, Exception exception)throws Exception {// TODO Auto-generated method stub}public void postHandle(HttpServletRequest request,HttpServletResponse response, Object object,ModelAndView modelAndView) throws Exception {}public boolean preHandle(HttpServletRequest request,HttpServletResponse response, Object handler) throws Exception {try {User user = userService.getUserById(request);if (userService.checkAuth(user, request, response)) {return true;} else {response.sendRedirect("/user/login.htm");return false;}} catch (Exception e) {e.printStackTrace();}response.sendRedirect("/user/login.htm");return false;} }?
package com.shishuo.studio.filter;import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse;import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; import org.springframework.web.servlet.HandlerInterceptor; import org.springframework.web.servlet.ModelAndView;import com.shishuo.studio.service.CategoryService;/*** @author Herbert* */ @Component public class GlobalInterceptor implements HandlerInterceptor {@Autowiredprivate CategoryService categoryService;@Overridepublic boolean preHandle(HttpServletRequest request,HttpServletResponse response, Object handler) throws Exception {return true;}@Overridepublic void postHandle(HttpServletRequest request,HttpServletResponse response, Object handler,ModelAndView modelAndView) throws Exception {if (null == modelAndView) {return;}// 系統(tǒng)配置參數(shù)modelAndView.addObject("categoryList",categoryService.getCategoryListOfDisplayByFatherId(0));}@Overridepublic void afterCompletion(HttpServletRequest request,HttpServletResponse response, Object handler, Exception ex)throws Exception {// TODO Auto-generated method stub}}?
package com.shishuo.studio.filter;import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse;import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; import org.springframework.web.servlet.HandlerInterceptor; import org.springframework.web.servlet.ModelAndView;import com.shishuo.studio.entity.User; import com.shishuo.studio.entity.vo.StudioVo; import com.shishuo.studio.exception.StudioNotFoundException; import com.shishuo.studio.service.StudioService; import com.shishuo.studio.service.UserService;/*** @author Herbert* */ @Component public class StudioInterceptor implements HandlerInterceptor {@Autowiredprivate StudioService studioService;@Autowiredprivate UserService userService;@Overridepublic boolean preHandle(HttpServletRequest request,HttpServletResponse response, Object handler) throws Exception {User user = userService.getUserById(request);try {StudioVo studio = studioService.getStudioById(user.getUserId());return true;} catch (StudioNotFoundException e) {response.sendRedirect("/auth/teacher/studio.htm");return false;}}@Overridepublic void postHandle(HttpServletRequest request,HttpServletResponse response, Object handler,ModelAndView modelAndView) throws Exception {}@Overridepublic void afterCompletion(HttpServletRequest request,HttpServletResponse response, Object handler, Exception ex)throws Exception {} }?
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