springboot拦截器（预先处理）

小咪咪 2023-10-06 22:14 36阅读 0赞

## 一、通过实现HandlerInterceptor 接口的方式 ##

### 1.1、创建一个登录拦截器 ###

/**
     * 登录检查
     * 1、配置好拦截器要拦截哪些请求
     * 2、把这些配置放在容器中
     */
    @Slf4j
    public class LoginInterceptor implements HandlerInterceptor {
        
        /*目标方法执行之前*/
        @Override
        public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        
            String requestURI = request.getRequestURI();
            log.info("preHandle拦截的请求路径是{}",requestURI);
    
            //登录检查逻辑
            HttpSession session = request.getSession();
            Object loginUser = session.getAttribute("loginUser");
            if(loginUser != null){
        
                //true放行，执行目标方法
                return true;
            }
    
            //拦截住，未登录，跳转到登录页，并添加提示信息
            request.setAttribute("msg","请先登录");
            request.getRequestDispatcher("/").forward(request,response);
            //false拦截
            return false;
        }
    
        /*目标方法执行完成以后 */
        @Override
        public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        
            log.info("postHandle执行{}",modelAndView);
        }
    
        /*页面渲染以后*/
        @Override
        public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        
            log.info("afterCompletion执行异常{}",ex);
        }
    }

### 1.2、配置和注册登录拦截器 ###

//@EnableWebMvc
    @Configuration
    //定制springmvc的功能
    public class AdminWebConfig implements WebMvcConfigurer{
        
        @Override
        public void addInterceptors(InterceptorRegistry registry) {
        
            //添加自定义拦截器LoginInterceptor
            registry.addInterceptor(new LoginInterceptor())
                    //所有请求都被拦截包括静态资源
                    .addPathPatterns("/**")
                    //放行的请求
                    .excludePathPatterns(
                            "/","/login",//放行登录页
                            "/css/**","/fonts/**","/images/**","/js/**","/aa/**");//放行静态资源
        }
    }

## 二、web自定义定制化，通过实现WebMvcConfigurer 接口的方式 ##

@Configuration
    public class InterceptorConfig implements WebMvcConfigurer {
        
    
        @Override
        public void addInterceptors(InterceptorRegistry registry) {
        
            registry.addInterceptor(jwtInterceptor())
                    .addPathPatterns("/**")  // 拦截所有请求，通过判断token是否合法来决定是否需要登录
                    .excludePathPatterns(
                            "/user/login", "/user/register", "/**/exportExcel", "/**/importExcel",
                            "/file/**","/swagger-resources/**", "/webjars/**", "/v2/**",
                            "/swagger-ui.html/**","**/swagger-ui/**", "/api", "/api-docs", "/api-docs/**")
                    // 放行静态文件
                    .excludePathPatterns( "/**/*.html", "/**/*.js", "/**/*.css", "/**/*.woff", "/**/*.ttf");
    
        }
    
        @Bean
        public JwtInterceptor jwtInterceptor() {
        
            return new JwtInterceptor();
        }
    
    }