解决跨域问题

1、如果是springMVC框架

      a） 继承Filter类，然后重写doFilter方法

　　

　　

        @Override
        public void doFilter(ServletRequest request, ServletResponse servletResponse,
                                       FilterChain chain) throws IOException, ServletException {

                  HttpServletResponse response = (HttpServletResponse) servletResponse;
                  response.setHeader("Access-Control-Allow-Origin", "*");
                  response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
                  response.setHeader("Access-Control-Max-Age", "3600");
                  response.setHeader("Access-Control-Allow-Headers", "x-requested-with,Authorization");
                  response.setHeader("Access-Control-Allow-Credentials","true");
                 chain.doFilter(request, servletResponse);

        }

2、如果是springBoot框架

  @Bean
  public FilterRegistrationBean corsFilter() {
      UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
      CorsConfiguration config = new CorsConfiguration();
      config.setAllowCredentials(true);
      config.addAllowedOrigin("*");
      config.addAllowedHeader("*");
      config.addAllowedMethod("*");
      source.registerCorsConfiguration("/**", config);
      FilterRegistrationBean bean = new FilterRegistrationBean(new CorsFilter(source));
      bean.setOrder(0);
      return bean;
  }