Interceptor,WebMvcConfigurationSupport,Cors 拦截器，全局跨域

1：实现 HandlerInterceptor 接口

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

    //登录之前的校验
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        logger.debug("登录之前的校验");
　　　　//todo　　拦截的功能
        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：实现 WebMvcConfigurationSupport 接口，重写 addInterceptors 方法， Configuration 注解标记为配置类

@Configuration
public class WebMvcConfig extends WebMvcConfigurationSupport {  //WebMvcConfigurerAdapter

    //拦截器注册
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
       // registry.addInterceptor(new TestInterceptor()).addPathPatterns("/**");  //  /**下的每一个接口都要有"登录"的校验
        registry.addInterceptor(new LoginInterceptor()).addPathPatterns("/mes");//mes下的接口都要被拦截
        super.addInterceptors(registry);
    }
    //全局跨域
    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")                      // 允许跨域访问的路径
   //         .allowedOrigins("http://domain2.com")                    //允许跨域访问的源
　　//                .allowedMethods("PUT", "DELETE")                  //允许请求方法
　　//                .allowedHeaders("header1", "header2", "header3")  //允许头部设置
　　//                .exposedHeaders("header1", "header2")
　　//                .allowCredentials(false).maxAge(3600);            //是否发送cookie，预检间隔时间
        ;
    　　}
　　//如果有安全框架，需要在框架中启用CORS;还有一种基于"过滤器"的跨域设置
　　}