springboot拦截器判断是否登录

实现拦截器的两个步骤

1. 自定义拦截器实现HandlerInterceptor接口
2. 创建一个配置类继承WebMvcConfigurerAdapter类并重写addInterceptors方法

代码

1、自定义拦截器

@Component
public class AdminLoginInterceptor implements HandlerInterceptor {

//    在请求处理之前调用,只有返回true才会执行请求
    @Override
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
//        得到session
        HttpSession session = httpServletRequest.getSession(true);
//        得到对象
        Object admin = session.getAttribute("admin");
//        判断对象是否存在
        if(admin!=null){
            return true;
        }else{
//            不存在则跳转到登录页
            httpServletResponse.sendRedirect(httpServletRequest.getContextPath()+"/login/adminLogin");
            return false;
        }
    }

//    试图渲染之后执行
    @Override
    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {

    }

//    在请求处理之后,视图渲染之前执行
    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {

    }
}

2、自定义配置类继承WebMvcConfigurerAdapter

@SpringBootConfiguration
public class AdminLoginAdapter extends WebMvcConfigurerAdapter {

    @Autowired
    AdminLoginInterceptor adminLoginInterceptor;

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(adminLoginInterceptor).addPathPatterns("/admin/**").excludePathPatterns("/login/**");
        super.addInterceptors(registry);
    }
}