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
*
*/
@Component
public 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 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> 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> queries) {
// 叶子节点
if (!jsonNode.isContainerNode()) {
if (jsonNode.isNull()) {
return;
}
Collection 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 it = jsonNode.elements();
while (it.hasNext()) {
buildQuery(it.next(), path, queries);
}
} else {
Iterator> it;
it = jsonNode.fields();
while (it.hasNext()) {
Map.Entry 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 processin g failed; nested exception is feign.RetryableException: too many bytes written executing POST http://pay/wx/create] with root cause java.io.IOException: too many bytes written at 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脚本之家。