如何在响应主体中为Cloud Api Gateway添加一些数据

Question

我在云API网关中添加了一些身份验证逻辑。我添加了GatewayFilter：

import java.util.List;

import org.springframework.cloud.gateway.filter.GatewayFilter;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.http.HttpStatus;
import org.springframework.util.CollectionUtils;
import org.springframework.util.PatternMatchUtils;
import org.springframework.web.server.ServerWebExchange;

import reactor.core.publisher.Mono;

public class AuthorizationFilter implements GatewayFilter {
  @Override
  public Mono<Void> filter(
    ServerWebExchange exchange, GatewayFilterChain chain) {
    List<String> authorization = exchange.getRequest().getHeaders().get("Authorization");
    if (CollectionUtils.isEmpty(authorization) &&
      !PatternMatchUtils.simpleMatch(URL_WITHOUT_AUTH, exchange.getRequest().getURI().toString())) {
      exchange.getResponse().setStatusCode(HttpStatus.UNAUTHORIZED);
      //Add some custom data in body of the response
      return exchange.getResponse().setComplete();
    }
    String token = authorization.get(0).split(" ")[1];
    // token validation
    return chain.filter(exchange);
  }
}

但我无法在响应正文中添加一些数据。您能帮我了解它的工作原理以及如何对其进行自定义吗？

PS我试图添加一些数据以响应使用通量，但它不起作用：

 DataBuffer b = exchange.getResponse().bufferFactory().allocateBuffer(256);
      b.write("12345".getBytes());
      return exchange.getResponse().writeWith(s -> Flux.just(b));

我做错了什么？

Answer 1

在 Spring 人员的一些帮助下，我能够使其工作。因此，我必须抛出自定义异常并正确处理它，而不是直接写入响应：

@Bean
public ErrorWebExceptionHandler myExceptionHandler() {
  return new MyWebExceptionHandler();
}

public class MyWebExceptionHandler implements ErrorWebExceptionHandler {
  @Override
  public Mono<Void> handle(
    ServerWebExchange exchange, Throwable ex) {
    byte[] bytes = "Some text".getBytes(StandardCharsets.UTF_8);
    DataBuffer buffer = exchange.getResponse().bufferFactory().wrap(bytes);
    return exchange.getResponse().writeWith(Flux.just(buffer));
  }
}