openFeign服务间调用保持请求头信息处理
1、注意特殊情况，在定时任务或者内部之间调用，没有request的时候，不要处理直接返回。
2、在GET请求，参数确放在Body里面传递的情况，restTemplate是不认识的，所以这里要转化下处理，然后清空body数据
3、在请求过程中如果出现java.io.IOException: too many bytes written异常，请参考保持请求头造成请求头和content-length不一致
/** * 解决服务调用丢失请求头的问题 * @author 大仙 * */@Componentpublic class FeignConfiguration implements RequestInterceptor{ private final Logger logger = LoggerFactory.getLogger(getClass()); @Autowired private ObjectMapper objectMapper; @Override public void apply(RequestTemplate template) { ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder .getRequestAttributes(); // 注意: RequestContextHolder依赖于 ThreadLocal, 所以在hystrix的隔离策略为THREAD、MQ的消费者、定时任务调用feignClient时，此处应为null if (attributes == null) { return; } HttpServletRequest request = attributes.getRequest(); Enumeration<String> headerNames = request.getHeaderNames(); if (headerNames != null) { while (headerNames.hasMoreElements()) { String name = headerNames.nextElement(); String values = request.getHeader(name); template.header(name, values); } } logger.info("保持请求头"); //feign 不支持 GET 方法传 POJO, json body转query if (template.method().equals("GET") && template.requestBody().asBytes() != null) { try { JsonNode jsonNode = objectMapper.readTree(template.requestBody().asBytes()); Request.Body.empty(); Map<String, Collection<String>> queries = new HashMap<>(); buildQuery(jsonNode, "", queries); template.queries(queries); } catch (IOException e) { //提示:根据实践项目情况处理此处异常，这里不做扩展。 e.printStackTrace(); } } } /** * 改造 * @param jsonNode * @param path * @param queries */ private void buildQuery(JsonNode jsonNode, String path, Map<String, Collection<String>> queries) { // 叶子节点 if (!jsonNode.isContainerNode()) { if (jsonNode.isNull()) { return; } Collection<String> values = queries.get(path); if (null == values) { values = new ArrayList<>(); queries.put(path, values); } values.add(jsonNode.asText()); return; } // 数组节点 if (jsonNode.isArray()) { Iterator<JsonNode> it = jsonNode.elements(); while (it.hasNext()) { buildQuery(it.next(), path, queries); } } else { Iterator<Map.Entry<String, JsonNode>> it; it = jsonNode.fields(); while (it.hasNext()) { Map.Entry<String, JsonNode> entry = it.next(); if (StringUtils.hasText(path)) { buildQuery(entry.getValue(), path + "." + entry.getKey(), queries); } else { // 根节点 buildQuery(entry.getValue(), entry.getKey(), queries); } } } }}
保持请求头造成请求头和content-length不一致
Request processin g failed； nested exception is feign.RetryableException: too many bytes written
2020-09-08 14:07:14.718 ERROR 16146 --- [io-12000-exec-5] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is feign.RetryableException: too many bytes written executing POST http://pay/wx/create] with root causejava.io.IOException: too many bytes writtenat sun.net.www.protocol.http.HttpURLConnection$StreamingOutputStream.write(HttpURLConnection.java:3574) ~[na:1.8.0_212]at sun.net.www.protocol.http.HttpURLConnection$StreamingOutputStream.write(HttpURLConnection.java:3565) ~[na:1.8.0_212]at feign.Client$Default.convertAndSend(Client.java:181) ~[feign-core-10.4.0.jar!/:na]at feign.Client$Default.execute(Client.java:77) ~[feign-core-10.4.0.jar!/:na]at org.springframework.cloud.openfeign.ribbon.RetryableFeignLoadBalancer$1.doWithRetry(RetryableFeignLoadBalancer.java:114) ~[spring-cloud-openfeign-core-2.1.5.RELEASE.jar!/:2.1.5.RELEASE]at org.springframework.cloud.openfeign.ribbon.RetryableFeignLoadBalancer$1.doWithRetry(RetryableFeignLoadBalancer.java:94) ~[spring-cloud-openfeign-core-2.1.5.RELEASE.jar!/:2.1.5.RELEASE]at org.springframework.retry.support.RetryTemplate.doExecute(RetryTemplate.java:287) ~[spring-retry-1.2.5.RELEASE.jar!/:na]at org.springframework.retry.support.RetryTemplate.execute(RetryTemplate.java:180) ~[spring-retry-1.2.5.RELEASE.jar!/:na]at org.springframework.cloud.openfeign.ribbon.RetryableFeignLoadBalancer.execute(RetryableFeignLoadBalancer.java:94) ~[spring-cloud-openfeign-core-2.1.5.RELEASE.jar!/:2.1.5.RELEASE]at org.springframework.cloud.openfeign.ribbon.RetryableFeignLoadBalancer.execute(RetryableFeignLoadBalancer.java:54) ~[spring-cloud-openfeign-core-2.1.5.RELEASE.jar!/:2.1.5.RELEASE]at com.netflix.client.AbstractLoadBalancerAwareClient$1.call(AbstractLoadBalancerAwareClient.java:104) ~[ribbon-loadbalancer-2.3.0.jar!/:2.3.0]at com.netflix.loadbalancer.reactive.LoadBalancerCommand$3$1.call(LoadBalancerCommand.java:303) ~[ribbon-loadbalancer-2.3.0.jar!/:2.3.0]at com.netflix.loadbalancer.reactive.LoadBalancerCommand$3$1.call(LoadBalancerCommand.java:287) ~[ribbon-loadbalancer-2.3.0.jar!/:2.3.0]at rx.internal.util.ScalarSynchronousObservable$3.call(ScalarSynchronousObservable.java:231) ~[rxjava-1.3.8.jar!/:1.3.8]at rx.internal.util.ScalarSynchronousObservable$3.call(ScalarSynchronousObservable.java:228) ~[rxjava-1.3.8.jar!/:1.3.8]at rx.Observable.unsafeSubscribe(Observable.java:10327) ~[rxjava-1.3.8.jar!/:1.3.8]at rx.internal.operators.OnSubscribeConcatMap$ConcatMapSubscriber.drain(OnSubscribeConcatMap.java:286) ~[rxjava-1.3.8.jar!/:1.3.8]at rx.internal.operators.OnSubscribeConcatMap$ConcatMapSubscriber.onNext(OnSubscribeConcatMap.java:144) ~[rxjava-1.3.8.jar!/:1.3.8]at com.netflix.loadbalancer.reactive.LoadBalancerCommand$1.call(LoadBalancerCommand.java:185) ~[ribbon-loadbalancer-2.3.0.jar!/:2.3.0]at com.netflix.loadbalancer.reactive.LoadBalancerCommand$1.call(LoadBalancerCommand.java:180) ~[ribbon-loadbalancer-2.3.0.jar!/:2.3.0]at rx.Observable.unsafeSubscribe(Observable.java:10327) ~[rxjava-1.3.8.jar!/:1.3.8]at rx.internal.operators.OnSubscribeConcatMap.call(OnSubscribeConcatMap.java:94) ~[rxjava-1.3.8.jar!/:1.3.8]at rx.internal.operators.OnSubscribeConcatMap.call(OnSubscribeConcatMap.java:42) ~[rxjava-1.3.8.jar!/:1.3.8]at rx.Observable.unsafeSubscribe(Observable.java:10327) ~[rxjava-1.3.8.jar!/:1.3.8]at rx.internal.operators.OperatorRetryWithPredicate$SourceSubscriber$1.call(OperatorRetryWithPredicate.java:127) ~[rxjava-1.3.8.jar!/:1.3.8]at rx.internal.schedulers.TrampolineScheduler$InnerCurrentThreadScheduler.enqueue(TrampolineScheduler.java:73) ~[rxjava-1.3.8.jar!/:1.3.8]at rx.internal.schedulers.TrampolineScheduler$InnerCurrentThreadScheduler.schedule(TrampolineScheduler.java:52) ~[rxjava-1.3.8.jar!/:1.3.8]at rx.internal.operators.OperatorRetryWithPredicate$SourceSubscriber.onNext(OperatorRetryWithPredicate.java:79) ~[rxjava-1.3.8.jar!/:1.3.8]at rx.internal.operators.OperatorRetryWithPredicate$SourceSubscriber.onNext(OperatorRetryWithPredicate.java:45) ~[rxjava-1.3.8.jar!/:1.3.8]at rx.internal.util.ScalarSynchronousObservable$WeakSingleProducer.request(ScalarSynchronousObservable.java:276) ~[rxjava-1.3.8.jar!/:1.3.8]at rx.Subscriber.setProducer(Subscriber.java:209) ~[rxjava-1.3.8.jar!/:1.3.8]at rx.internal.util.ScalarSynchronousObservable$JustOnSubscribe.call(ScalarSynchronousObservable.java:138) ~[rxjava-1.3.8.jar!/:1.3.8]at rx.internal.util.ScalarSynchronousObservable$JustOnSubscribe.call(ScalarSynchronousObservable.java:129) ~[rxjava-1.3.8.jar!/:1.3.8]at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48) ~[rxjava-1.3.8.jar!/:1.3.8]at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30) ~[rxjava-1.3.8.jar!/:1.3.8
原因是：body是跟Content-Length 有关系
复制的时候是所有头都复制的,可能导致Content-length长度跟body不一致. 所以只需要判断如果是Content-length就跳过
解决方式：更改复制逻辑
while (headerNames.hasMoreElements()) { String name = headerNames.nextElement(); // 跳过 content-length if (name.equals("content-length")){ continue; } String values = request.getHeader(name); template.header(name, values); }
以上为个人经验，希望能给大家一个参考，也希望大家多多支持。
梦想让我与众不同，奋斗让我改变命运！
