Java跨域问题

方式一:注解方式

// 将跨域访问的接口添加此注解, 也可放在Controller上
@CrossOrigin(origins = "*", maxAge = 3600)

方式二: 全局加, 在启动类中添加以下代码(效果同方式一)

    @Bean
    public CorsFilter corsFilter() {
        final UrlBasedCorsConfigurationSource urlBasedCorsConfigurationSource = new UrlBasedCorsConfigurationSource();
        final CorsConfiguration corsConfiguration = new CorsConfiguration();
        corsConfiguration.setAllowCredentials(true);
        corsConfiguration.addAllowedOrigin("*");
        corsConfiguration.addAllowedHeader("*");
        corsConfiguration.addAllowedMethod("*");
        urlBasedCorsConfigurationSource.registerCorsConfiguration("/**", corsConfiguration);
        return new CorsFilter(urlBasedCorsConfigurationSource);
    }

重点:以上两种方法会造成 拦截器 走两遍, 如果有在header 中取值时, 第一遍取不到, 导致报错

方式三 终极版

@Order(Ordered.HIGHEST_PRECEDENCE)
@WebFilter(filterName = "crossFilter", urlPatterns = "/*")
@Component
public class CrossFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest servletRequest = (HttpServletRequest) request;
        HttpServletResponse servletResponse = (HttpServletResponse) response;
        servletResponse.setHeader("Access-Control-Allow-Origin", servletRequest.getHeader("Origin"));
        servletResponse.setHeader("Access-Control-Allow-Methods", "GET, POST, OPTIONS, PUT, DELETE,PATCH");
        servletResponse.setHeader("Access-Control-Allow-Headers", "DNT,X-Mx-ReqToken,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Authorization,SessionToken,Cookie");
        servletResponse.setHeader("Access-Control-Max-Age", "3600");
        servletResponse.setHeader("Access-Control-Allow-Credentials", "true");
        servletResponse.setHeader("Access-Control-Expose-Headers", "*");

        //判断是否为可选择性批量操作的请求，设置状态码返回
        if ("OPTIONS".equals(servletRequest.getMethod())) {
            servletResponse.setStatus(HttpStatus.ACCEPTED.value());
            return;
        }
        filterChain.doFilter(request, response);
    }

    @Override
    public void destroy() {
    }
}