Question

第六章：如何在SpringBoot项目中使用拦截器

Answer 1

1. 拦截器接口 HandlerInterceptor

   public interface HandlerInterceptor {
   
   boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
   throws Exception;
   
   
   void postHandle(
   HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView)
   throws Exception;
   
   
   void afterCompletion(
   HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
   throws Exception;
   
   }

2. public class Myfilter  implements  HandlerInterceptor{
   
   /**
   * 页面渲染之后调用，一般用于资源清理操作
   */
   @Override
   public void afterCompletion(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, Exception arg3)
   throws Exception {
   // TODO Auto-generated method stub
   System.out.println("------afterCompletion-----");
   
   }
   /**
   * controller 执行之后，且页面渲染之前调用
   */
   @Override
   public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, ModelAndView arg3)
   throws Exception {
   // TODO Auto-generated method stub
   System.out.println("------postHandle-----");
   }
   
   /**
   * controller 执行之前调用
   */
   
   @Override
   public boolean preHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2) throws Exception {
   // TODO Auto-generated method stub
   System.out.println("------preHandle-----");
   return true;
   }
   
   }
   
   3.//将Myfilter拦截器放到SpringBoot的配置中
   

   

3. @GetMapping("/www/ijava")
   public String home(){
   System.out.println("--- wwww . ijava ---");
   return "user home";
   }