零基础入门SpringMVC拦截器的配置与使用

//自己编写一个类PreInterceptor 实现 HandlerInterceptor接口 , 重写preHandle方法

public class PreInterceptor implements HandlerInterceptor {

     //此方法返回true ,请求才能顺利到达相应的处理方法中,否则会被拦截

     @Override

     public boolean preHandle(HttpServletRequest request,

             HttpServletResponse response, Object handler) throws Exception {

         //第三个参数为目标控制器对象

         HttpSession session= request.getSession();

         //判断信息是否有效

         Admin admin = (Admin) session.getAttribute( "admin" );

         if (admin== null ){

             response.getWriter().print( 202 );

             return false ;

         } else {

             return true ;

         }

     }

}

<!--配置拦截器-->

< mvc:interceptors >

     < mvc:interceptor >

         <!--所有请求都进入拦截器-->

         < mvc:mapping path = "/**" />

         <!--指定哪些请求不进入拦截器-->

         < mvc:exclude-mapping path = "/login/login" />

         < mvc:exclude-mapping path = "/css/**" />

         < mvc:exclude-mapping path = "/images/**" />

         < mvc:exclude-mapping path = "/js/**" />

         < mvc:exclude-mapping path = "/**.html" />

         <!--拦截器实现类-->

         < bean id = "login" class = "com.ff.ssm.util.PreInterceptor" />

     </ mvc:interceptor >

</ mvc:interceptors >

@RestController

@RequestMapping (value = "/login" )

public class LoginController {

     @Autowired

     LoginService loginService;

     @PostMapping (value = "/login" )

     public CommonResult adminLogin(Admin admin, HttpSession session){

         CommonResult commonResult;

         try {

             Admin admin1 = loginService.login(admin);

             if (admin1== null ){

                 commonResult= new CommonResult( 201 , "账号或密码错误" ,admin1);

             } else   {

                 session.setAttribute( "admin" ,admin1);

                 commonResult= new CommonResult( 200 , "登录成功" ,admin1);

             }

         } catch (Exception e){

             commonResult= new CommonResult( 500 , "登录失败" , "" );

         }

         return commonResult;

     }

}