springcloudgateway读取requestbody数据

spring cloud gateway为了记录访问记录,需要记录请求体里面的内容,但是 request body是只能读取一次的,如果读取以后不封装回去,则会造成后面的服务无法读取body数据. 在网关里添加一个过滤器RequestRecordFilter类:

&＃64;Slf4j
&＃64;Component
public class RequestRecordFilter implements GlobalFilter, Ordered {&＃64;Overridepublic Mono filter(ServerWebExchange exchange, GatewayFilterChain chain) {ServerHttpRequest request &＃61; exchange.getRequest();URI requestUri &＃61; request.getURI();//只记录 http 请求(包含 https)String schema &＃61; requestUri.getScheme();if ((!"http".equals(schema) && !"https".equals(schema))){return chain.filter(exchange);}AccessRecord accessRecord &＃61; new AccessRecord();accessRecord.setPath(requestUri.getPath());accessRecord.setQueryString(request.getQueryParams());exchange.getAttributes().put("startTime", System.currentTimeMillis());String method &＃61; request.getMethodValue();String contentType &＃61; request.getHeaders().getFirst("Content-Type");//此处要排除流文件类型,比如上传的文件if ("POST".equals(method) && !contentType.startsWith("multipart/form-data")){String bodyStr &＃61; resolveBodyFromRequest(request);//下面将请求体再次封装写回到 request 里,传到下一级.URI ex &＃61; UriComponentsBuilder.fromUri(requestUri).build(true).toUri();ServerHttpRequest newRequest &＃61; request.mutate().uri(ex).build();DataBuffer bodyDataBuffer &＃61; stringBuffer(bodyStr);Flux bodyFlux &＃61; Flux.just(bodyDataBuffer);newRequest &＃61; new ServerHttpRequestDecorator(newRequest) {&＃64;Overridepublic Flux getBody() {return bodyFlux;}};accessRecord.setBody(formatStr(bodyStr));ServerWebExchange newExchange &＃61; exchange.mutate().request(newRequest).build();return returnMono(chain, newExchange, accessRecord);} else {return returnMono(chain, exchange, accessRecord);}}private Mono returnMono(GatewayFilterChain chain,ServerWebExchange exchange, AccessRecord accessRecord){return chain.filter(exchange).then(Mono.fromRunnable(()->{Long startTime &＃61; exchange.getAttribute("startTime");if (startTime !&＃61; null){long executeTime &＃61; (System.currentTimeMillis() - startTime);accessRecord.setExpendTime(executeTime);accessRecord.setHttpCode(Objects.requireNonNull(exchange.getResponse().getStatusCode()).value());writeAccessLog(JSON.toJSONString(accessRecord) &＃43; "\r\n");}}));}&＃64;Overridepublic int getOrder() {return 1;}/*** 获取请求体中的字符串内容* &＃64;param serverHttpRequest* &＃64;return*/private String resolveBodyFromRequest(ServerHttpRequest serverHttpRequest){//获取请求体Flux body &＃61; serverHttpRequest.getBody();StringBuilder sb &＃61; new StringBuilder();body.subscribe(buffer -> {byte[] bytes &＃61; new byte[buffer.readableByteCount()];buffer.read(bytes);DataBufferUtils.release(buffer);String bodyString &＃61; new String(bytes, StandardCharsets.UTF_8);sb.append(bodyString);});return sb.toString();}/*** 去掉空格,换行和制表符* &＃64;param str* &＃64;return*/private String formatStr(String str){if (str !&＃61; null && str.length() > 0) {Pattern p &＃61; Pattern.compile("\\s*|\t|\r|\n");Matcher m &＃61; p.matcher(str);return m.replaceAll("");}return str;}private DataBuffer stringBuffer(String value){byte[] bytes &＃61; value.getBytes(StandardCharsets.UTF_8);NettyDataBufferFactory nettyDataBufferFactory &＃61; new NettyDataBufferFactory(ByteBufAllocator.DEFAULT);DataBuffer buffer &＃61; nettyDataBufferFactory.allocateBuffer(bytes.length);buffer.write(bytes);return buffer;}/*** 访问记录对象*/&＃64;Dataprivate class AccessRecord{private String path;private String body;private MultiValueMap queryString;private long expendTime;private int httpCode;}private void writeAccessLog(String str){File file &＃61; new File("access.log");if (!file.exists()){try {if (file.createNewFile()){file.setWritable(true);}} catch (IOException e) {log.error("创建访问日志文件失败.{}",e.getMessage(),e);}}try(FileWriter fileWriter &＃61; new FileWriter(file.getName(),true)){fileWriter.write(str);} catch (IOException e) {log.error("写访问日志到文件失败. {}", e.getMessage(),e);}}
}


网上有个获取 body的写法, 但是这种写法对请求体的字符串长度有限制,稍微长一点, 就会转换不完整,方法如下:

private String resolveBodyFromRequest(ServerHttpRequest serverHttpRequest) {//获取请求体Flux body &＃61; serverHttpRequest.getBody();AtomicReference bodyRef &＃61; new AtomicReference<>();body.subscribe(buffer -> {CharBuffer charBuffer &＃61; StandardCharsets.UTF_8.decode(buffer.asByteBuffer());DataBufferUtils.release(buffer);bodyRef.set(charBuffer.toString());});//获取request bodyreturn bodyRef.get();}


对于出现 Only one connection receive subscriber allowed&＃xff0c;或者 response is set之类的信息&＃xff0c;这个是springboot2.0.5之后的一个bug&＃xff0c;需要在类里面添加以下方法去实现&＃xff08;这个是springboot开发成员提供的方法&＃xff09;&＃xff1a;

&＃64;Beanpublic HiddenHttpMethodFilter hiddenHttpMethodFilter() {return new HiddenHttpMethodFilter() {&＃64;Overridepublic Mono filter(ServerWebExchange exchange, WebFilterChain chain) {return chain.filter(exchange);}};}