@Override
public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
    ServerHttpResponse response = exchange.getResponse();
    DataBufferFactory bufferFactory = response.bufferFactory();
    ServerHttpResponseDecorator decoratedResponse = new ServerHttpResponseDecorator(response) {
        @Override
        public Mono<Void> writeWith(Publisher<? extends DataBuffer> body) {
            if (body instanceof Flux) {
                Flux<? extends DataBuffer> fluxBody = (Flux<? extends DataBuffer>) body;
                return super.writeWith(fluxBody.map(dataBuffer -> {
                    // probably should reuse buffers
                    byte[] content = new byte[dataBuffer.readableByteCount()];
                    dataBuffer.read(content);
                    //释放掉内存
                    DataBufferUtils.release(dataBuffer);
                    return bufferFactory.wrap(content);
                }));
            }
            // if body is not a flux. never got there.
            return super.writeWith(body);
        }
    };
    return chain.filter(exchange.mutate().response(decoratedResponse).build()).then(Mono.fromRunnable(()->{
        accessLogService.sendLog(exchange, null);
    }));
}
 

private void setResponseStatus(HttpClientResponse clientResponse,
		ServerHttpResponse response) {
	HttpStatus status = HttpStatus.resolve(clientResponse.status().code());
	if (status != null) {
		response.setStatusCode(status);
	}
	else {
		while (response instanceof ServerHttpResponseDecorator) {
			response = ((ServerHttpResponseDecorator) response).getDelegate();
		}
		if (response instanceof AbstractServerHttpResponse) {
			((AbstractServerHttpResponse) response)
					.setStatusCodeValue(clientResponse.status().code());
		}
		else {
			// TODO: log warning here, not throw error?
			throw new IllegalStateException("Unable to set status code "
					+ clientResponse.status().code() + " on response of type "
					+ response.getClass().getName());
		}
	}
}
 

/**
 * 响应消息输出过滤器
 *
 * @param exchange ServerWebExchange
 * @param chain    GatewayFilterChain
 * @return Mono
 */
@Override
public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
    ServerHttpResponse originalResponse = exchange.getResponse();
    ServerHttpResponseDecorator responseDecorator = new ServerHttpResponseDecorator(originalResponse) {

        @Override
        public Mono<Void> writeWith(Publisher<? extends DataBuffer> body) {
            Boolean logResult = exchange.getAttribute("logResult");
            if (logResult == null || !logResult) {
                return super.writeWith(body);
            }

            if (body instanceof Flux) {
                Flux<? extends DataBuffer> fluxBody = Flux.from(body);

                return super.writeWith(fluxBody.buffer().map(dataBuffers -> {
                    List<String> list = new ArrayList<>();
                    dataBuffers.forEach(dataBuffer -> {
                        byte[] content = new byte[dataBuffer.readableByteCount()];
                        dataBuffer.read(content);
                        DataBufferUtils.release(dataBuffer);
                        list.add(new String(content, StandardCharsets.UTF_8));
                    });

                    String json = String.join("", list);
                    logger.info("返回数据: {}", json);

                    return bufferFactory().wrap(json.getBytes());
                }));
            }

            return super.writeWith(body);
        }
    };
    // replace response with decorator
    return chain.filter(exchange.mutate().response(responseDecorator).build());
}
 

@Override
public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
    URI requestUri = exchange.getRequest().getURI();
    ServerHttpResponseDecorator decoratedResponse = new ServerHttpResponseDecorator(exchange.getResponse()) {
        @Override
        public Mono<Void> writeWith(Publisher<? extends DataBuffer> body) {
            switch (getStatusCode()) {
                case MOVED_PERMANENTLY: //301
                case FOUND: //302
                    HttpHeaders headers = getHeaders();
                    String location = headers.getFirst(HttpHeaders.LOCATION);
                    if (!StringUtils.isEmpty(location)) {
                        UriComponentsBuilder uriComponentsBuilder = UriComponentsBuilder.fromHttpUrl(location);
                        // replace scheme//host:port with original request's
                        uriComponentsBuilder.scheme(requestUri.getScheme())
                                .host(requestUri.getHost())
                                .port(requestUri.getPort());
                        String newLocation = uriComponentsBuilder.build().toUri().toString();
                        headers.put(HttpHeaders.LOCATION, Collections.singletonList(newLocation));

                        log.info("301/302 redirect in R: {}, FIX location {} -> {}", requestUri, location, newLocation);
                    }
                    break;

                default:
                    break;
            }

            return super.writeWith(body);
        }
    };

    // replace response with decorator
    return chain.filter(exchange.mutate().response(decoratedResponse).build());
}
 

@Test
public void notAbstractServerHttpResponse() {
	ServerWebExchange mockExchange = mock(ServerWebExchange.class);
	ServerHttpResponseDecorator responseDecorator = new ServerHttpResponseDecorator(
			new MockServerHttpResponse());
	responseDecorator.setStatusCode(OK);

	when(mockExchange.getRequest())
			.thenReturn(MockServerHttpRequest.get(ROUTE_URI).build());
	when(mockExchange.getResponse()).thenReturn(responseDecorator);

	Tags tags = tagsProvider.apply(mockExchange);
	assertThat(tags).isEqualTo(DEFAULT_TAGS);
}
 

@Override
protected byte[] modifyResponse(
        final InputStream responseBody,
        final Config config,
        final ServerHttpResponseDecorator decorator,
        final ServerWebExchange exchange)
        throws IOException {

    String[] keyValue = config.getData().split(",");

    String oldBase = StringUtils.appendIfMissing(keyValue[0], "/");
    String newBase = StringUtils.appendIfMissing(keyValue[1], "/");
    String newBaseAsPrefix = StringUtils.removeEnd(keyValue[1], "/");

    boolean rewriterRootAttrs = true;
    if (keyValue.length == 3) {
        rewriterRootAttrs = BooleanUtils.toBoolean(keyValue[2]);
    }

    Document doc = Jsoup.parse(
            responseBody, getCharset(decorator).name(), exchange.getRequest().getURI().toASCIIString());

    if (rewriterRootAttrs) {
        replace(doc, "a", "href", newBaseAsPrefix);
        replace(doc, "link", "href", newBaseAsPrefix);
        replace(doc, "img", "src", newBaseAsPrefix);
        replace(doc, "script", "src", newBaseAsPrefix);
        replace(doc, "object", "data", newBaseAsPrefix);
    }

    return doc.toString().replace(oldBase, newBase).getBytes();
}
 

@Override
protected boolean skipCond(final ServerHttpResponseDecorator decorator) {
    return decorator.getHeaders().getContentType() == null
            || !StringUtils.containsIgnoreCase(decorator.getHeaders().getContentType().toString(), "html");
}
 

private Charset getCharset(final ServerHttpResponseDecorator decorator) {
    return decorator.getHeaders().getContentType() != null
            && decorator.getHeaders().getContentType().getCharset() != null
            ? decorator.getHeaders().getContentType().getCharset()
            : StandardCharsets.UTF_8;
}
 

protected abstract byte[] modifyResponse(
InputStream responseBody,
Config config,
ServerHttpResponseDecorator decorator,
ServerWebExchange exchange)
throws IOException;
 

protected boolean skipCond(final ServerHttpResponseDecorator decorator) {
    LOG.debug("Decorator: {}", decorator);
    return false;
}