import javax.validation.Valid;
@CrossOrigin
@RestController
@RequestMapping("/user")
public class UserController{

 @CrossOrigin
  @ApiOperation(value = "用戶登錄",notes = "")
  @PostMapping("/loginOn")
  public ResponseMessage loginOn(@RequestBody @Valid UserReq userReq){

@Configuration
public class WebConfig implements WebMvcConfigurer {

  /**
   * 跨域支持
   * @param registry
   */
  @Override
  public void addCorsMappings(CorsRegistry registry) {
    registry.addMapping("/**")
        .allowedOrigins("*")
        .allowCredentials(true)
        .allowedMethods("GET", "POST", "DELETE", "PUT")
        .maxAge(3600 * 24);
  }

@Component
public class RequestInterceptor implements HandlerInterceptor {
  @Override
  public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
    Object loginUser = request.getSession().getAttribute("token");
    if(loginUser == null){
　　　　　　　　//自定義的異常類，這里拋出異常，交給全局異常捕捉類處理
      throw new ServiceException("沒有權限，請先登錄!");
    }else{
      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 {

  }
}

@RestControllerAdvice
public class GlobleExceptionHandler {
  @ExceptionHandler(value = ServiceException.class)
  public ResponseMessage caughtException(ServiceException e){

    return new ResponseMessage(e.getMsg());
  }
}

@Data
public class ResponseMessage {
  private Integer Code;
  private String msg;
  private Integer count;
  private Object data;

  public ResponseMessage(Object data) {
    this.data = data;
  }

  public ResponseMessage(String msg) {
    this.msg = msg;
  }

  public ResponseMessage(Integer code, String msg) {
    Code = code;
    this.msg = msg;
  }

  public ResponseMessage(Integer code, String msg, Integer count) {
    Code = code;
    this.msg = msg;
    this.count = count;
  }

  public ResponseMessage(Integer code, String msg, Integer count, Object data) {
    Code = code;
    this.msg = msg;
    this.count = count;
    this.data = data;
  }

  public static ResponseMessage success(String msg){
    return new ResponseMessage(200,msg);
  }

  public static ResponseMessage fail(Integer code,String msg){
    return new ResponseMessage(code,msg);
  }
}

@Configuration
public class MyCorsConfig {

  @Bean
  public CorsFilter corsFilter() {

    CorsConfiguration corsConfiguration = new CorsConfiguration();
    corsConfiguration.addAllowedOrigin("*");
    corsConfiguration.addAllowedHeader("*");
    corsConfiguration.addAllowedMethod("*");
    corsConfiguration.setAllowCredentials(true);
    corsConfiguration.setMaxAge(3600L);

    UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
    source.registerCorsConfiguration("/**", corsConfiguration);
    FilterRegistrationBean bean = new FilterRegistrationBean(new CorsFilter(source));
    //設置過濾器的順序
    bean.setOrder(0);
    return new CorsFilter(source);
  }
}