interceptor和filter类似
package com.itheima.interceptor; import org.springframework.web.servlet.HandlerInterceptor; import org.springframework.web.servlet.ModelAndView; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; public class MyInterceptor1 implements HandlerInterceptor { //在目标方法执行之前 执行 public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws ServletException, IOException { System.out.println("preHandle....."); String param = request.getParameter("param"); if("yes".equals(param)){ return true; }else{ request.getRequestDispatcher("/error.jsp").forward(request,response); return false;//返回true代表放行 返回false代表不放行 } } //在目标方法执行之后 视图对象返回之前执行 public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) { modelAndView.addObject("name","itheima"); System.out.println("postHandle..."); } //在流程都执行完毕后 执行 public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) { System.out.println("afterCompletion...."); } }
Spring-mvc.xml 需添加配置
<!--配置拦截器(多个interceptor配置顺序决定运行顺序)-->
<mvc:interceptors>
<mvc:interceptor>
<!--对哪些资源执行拦截操作-->
<mvc:mapping path="/**"/>
<bean class="com.example.springMVC.interceptor.MyInterceptor1"/>
</mvc:interceptor>
<mvc:interceptor>
<!--对哪些资源执行拦截操作-->
<mvc:mapping path="/**"/>
<bean class="com.example.springMVC.interceptor.MyInterceptor2"/>
</mvc:interceptor>
</mvc:interceptors>
输出结果应该为
preHandle.....
preHandle.....
preHandle22222.....
postHandle2222...
postHandle...
afterCompletion2222....
afterCompletion....