@Component
public class AuthGlobalFilterFilter implements GlobalFilter, Ordered {
    private static final String HEADER_KEY= "KEY";
    private static final String HEADER_LKEY = "LKEY";

    @Autowired
    ILoginInfoService loginInfoServiceImpl;

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {

        if(不满足一定条件){

     ServerHttpResponse serverHttpResponse = exchange.getResponse();
        serverHttpResponse.setStatusCode(HttpStatus.UNAUTHORIZED);
        byte[] bytes = "{\"status\":\"-1\",\"msg\":\"error\"}".getBytes(StandardCharsets.UTF_8);
        DataBuffer buffer = exchange.getResponse().bufferFactory().wrap(bytes);
        return exchange.getResponse().writeWith(Flux.just(buffer));

}       

参考:https://stackoverflow.com/questions/48491098/how-to-add-some-data-in-body-of-response-for-cloud-api-gateway