Interceptor,WebMvcConfigurationSupport,Cors 攔截器，全局跨域

1：實現 HandlerInterceptor 接口

public class LoginInterceptor implements HandlerInterceptor {
    static Log logger = LogFactory.getLog(LoginInterceptor.class);

    //登錄之前的校驗
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        logger.debug("登錄之前的校驗");
　　　　//todo　　攔截的功能
        return true;
    }
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
    }
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
    }
}

2：實現 WebMvcConfigurationSupport 接口，重寫 addInterceptors 方法， Configuration 注解標記為配置類

@Configuration
public class WebMvcConfig extends WebMvcConfigurationSupport {  //WebMvcConfigurerAdapter

    //攔截器注冊
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
       // registry.addInterceptor(new TestInterceptor()).addPathPatterns("/**");  //  /**下的每一個接口都要有"登錄"的校驗
        registry.addInterceptor(new LoginInterceptor()).addPathPatterns("/mes");//mes下的接口都要被攔截
        super.addInterceptors(registry);
    }
    //全局跨域
    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")                      // 允許跨域訪問的路徑
   //         .allowedOrigins("http://domain2.com")                    //允許跨域訪問的源
　　//                .allowedMethods("PUT", "DELETE")                  //允許請求方法
　　//                .allowedHeaders("header1", "header2", "header3")  //允許頭部設置
　　//                .exposedHeaders("header1", "header2")
　　//                .allowCredentials(false).maxAge(3600);            //是否發送cookie，預檢間隔時間
        ;
    　　}
　　//如果有安全框架，需要在框架中啟用CORS;還有一種基於"過濾器"的跨域設置
　　}