拦截器在ssm和springboot中的使用

拦截器在ssm和springboot中的使用

ssm拦截器的使用

1. 在spring-mvc引入

    
       <mvc:interceptors>
           <mvc:interceptor>
               
               <mvc:mapping path="/**"/>
               
               <mvc:exclude-mapping path="/login" />
               
               <bean class="com.w.interceptor.LoginInterceptor">bean>
           mvc:interceptor>
       mvc:interceptors>
   

2. 编写拦截处理类

   package com.w.interceptor;
   
   import javax.servlet.http.HttpServletRequest;
   import javax.servlet.http.HttpServletResponse;
   
   
   import org.springframework.web.servlet.HandlerInterceptor;
   
   public class LoginInterceptor implements HandlerInterceptor {
       
     //1、执行完毕，返回前拦截 --afterCompletion
     //2、在处理过程中，执行拦截-- postHandle
     //3、执行前进行拦截—preHandle（常用）
       
       @Override
       public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
   
           Integer uid = (Integer) request.getSession().getAttribute("uid");
           if(uid != null){
               // 登录成功不拦截
               return true;
           }else{
               // 拦截后进入登录页面
               response.sendRedirect(request.getContextPath()+"/login");//重定向
               return false;
           }
   
       }
   }
   
   

   springboot拦截器

   1. 编写拦截类实现HandlerInterceptor接口

      package com.w.interceptor;
      
      import lombok.extern.slf4j.Slf4j;
      import org.springframework.web.servlet.HandlerInterceptor;
      
      import javax.servlet.http.HttpServletRequest;
      import javax.servlet.http.HttpServletResponse;
      import javax.servlet.http.HttpSession;
      
      @Slf4j
      public class Interceptor implements HandlerInterceptor {
      	
          //方法执行前
          @Override
          public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
      
      
              String requestURI = request.getRequestURI();
              log.info("preHandle拦截的请求是:",requestURI);
      
              HttpSession session = request.getSession();
              Object ok = session.getAttribute("ok");
      
              if (ok != null){
                  //放行
                  return true;
              }else{
                  //拦截到，跳转到留言界面
                  request.setAttribute("msg","先发个留言呗！");
                  request.getRequestDispatcher("/wall").forward(request,response);
                  return false;
              }
      
      
          }
      }
      
      

      2. 拦截器注册到容器中（实现WebMvcConfigurer的addInterceptors）

         package com.w.config;
         
         import com.w.interceptor.Interceptor;
         import org.springframework.context.annotation.Configuration;
         import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
         import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
         
         /**
          * 1、编写一个拦截器实现HandlerInterceptor接口
          * 2、拦截器注册到容器中（实现WebMvcConfigurer的addInterceptors）
          * 3、指定拦截规则【如果是拦截所有，静态资源也会被拦截】
          */
         @Configuration
         public class LybWebConfig implements WebMvcConfigurer {
             @Override
             public void addInterceptors(InterceptorRegistry registry) {
                 registry.addInterceptor(new Interceptor())
                         .addPathPatterns("/getAll");
         			// .addPathPatterns("/**")  //所有请求都被拦截包括静态资源
                      //   .excludePathPatterns("/","/login","/css/**","/fonts/**","/images/**","/js/**"); //放行的请求
             }
         }