SpringBoot注册Fiter(过滤器)和Listener（监听器）

痛定思痛。 2022-05-08 15:08 226阅读 0赞

一、SpingBoot注册Filter

1、创建filter类及其注册配置类，用于过滤某些需要登陆后才可以访问的接口

自定义过滤器
    @Component
    public class PayFilter implements Filter {
        @Override
        public void init(FilterConfig filterConfig) throws ServletException {}
    
        @Override
        public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
            HttpServletRequest  request= (HttpServletRequest) servletRequest;
            Boolean f= (Boolean) request.getSession().getAttribute("login");
            if (f!=null&&f){
               filterChain.doFilter(servletRequest,servletResponse);
            }else {
                System.out.println("***********您还未登陆，请登录后操作***********");
            }
        }
    
        @Override
        public void destroy() {}
    }

向spring容器中注册PayFilter
    @Configuration
    public class PayFilterConfigure {
        private final PayFilter  payFilter;
        @Autowired
        public PayFilterConfigure(PayFilter payFilter) {
            this.payFilter = payFilter;
        }
        @Bean
        public FilterRegistrationBean  registrationBean(){
            FilterRegistrationBean<PayFilter> bean=new FilterRegistrationBean<>();
            bean.setFilter(payFilter);
            bean.addUrlPatterns("/pay/*");  //过滤/pay相关的url
            return bean;
        }
    }

2、创建支付和登陆的controller类

//登陆接口
    @Controller
    public class UserCtl {
        @GetMapping("/login")
        @ResponseBody
        public  String  login(HttpServletRequest request){
            request.getSession().setAttribute("login",true);
            return "登陆成功";
        }
    }
    
    //支付接口
    @RestController
    @RequestMapping("/pay")
    public class PayCtl {
        @GetMapping("/order")
        public String    pay(){
            return "恭喜您，订单支付成功";
        }
    }

二、SpringBoot注册监听器

javaweb共有8种类监听器

![70][]此处以ServletContextListener为例

/**
     * 自定义监听器
     */
    @Component
    public class PayContextListener implements HttpSessionListener {
    
        private int count;
    
        @Override
        public void sessionCreated(HttpSessionEvent httpSessionEvent) {
            count++;
            ServletContext servletContext= httpSessionEvent.getSession().getServletContext();
            servletContext.setAttribute("count",count);
            System.out.println("PayContextListener监听在线人数count="+count+"人");
        }
    
        @Override
        public void sessionDestroyed(HttpSessionEvent httpSessionEvent) {
           count--;
            ServletContext servletContext= httpSessionEvent.getSession().getServletContext();
            servletContext.setAttribute("count",count);
        }
    }
    
    
    /**
     * 配置监听器
     */
    @Configuration
    public class PayListenerConfigure {
    
       private final PayContextListener payListener;
    
        @Autowired
        public PayListenerConfigure(PayContextListener payListener) {
            this.payListener = payListener;
        }
    
        @Bean
        public ServletListenerRegistrationBean  payListener(){
            ServletListenerRegistrationBean<PayContextListener>  payListenerBean=new ServletListenerRegistrationBean<>();
            payListenerBean.setListener(payListener);
            System.out.println("PayContextListener被注入到spring容器");
            return  payListenerBean;
        }
    
    }

[70]: /images/20220506/2e7a67ea482340d18e6d1dc5f3d66e1f.png