springboot拦截器（预先处理）

Posted 2022-04-05 江州益彤

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();