ClassInstance

feign调用报错：

Caused by: feign.RetryableException: cannot retry due to redirection, in streaming mode executing POST http://G-PC-PERSON-CENTER/person/privilege/doSendOrderPayStatus
	at feign.FeignException.errorExecuting(FeignException.java:132)
	at feign.SynchronousMethodHandler.executeAndDecode(SynchronousMethodHandler.java:113)
	at feign.SynchronousMethodHandler.invoke(SynchronousMethodHandler.java:78)
	at feign.hystrix.HystrixInvocationHandler$1.run(HystrixInvocationHandler.java:109)
	at com.netflix.hystrix.HystrixCommand$2.call(HystrixCommand.java:302)
	at com.netflix.hystrix.HystrixCommand$2.call(HystrixCommand.java:298)
	at rx.internal.operators.OnSubscribeDefer.call(OnSubscribeDefer.java:46)
	... 131 more
Caused by: java.net.HttpRetryException: cannot retry due to redirection, in streaming mode
	at sun.net.www.protocol.http.HttpURLConnection.followRedirect0(HttpURLConnection.java:2655)
	at sun.net.www.protocol.http.HttpURLConnection.followRedirect(HttpURLConnection.java:2641)
	at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1824)
	at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1492)
	at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:480)
	at feign.Client$Default.convertResponse(Client.java:143)
	at feign.Client$Default.execute(Client.java:68)
	at org.springframework.cloud.openfeign.ribbon.FeignLoadBalancer.execute(FeignLoadBalancer.java:93)
	at org.springframework.cloud.openfeign.ribbon.FeignLoadBalancer.execute(FeignLoadBalancer.java:56)
	at com.netflix.client.AbstractLoadBalancerAwareClient$1.call(AbstractLoadBalancerAwareClient.java:104)
	at com.netflix.loadbalancer.reactive.LoadBalancerCommand$3$1.call(LoadBalancerCommand.java:303)
	at com.netflix.loadbalancer.reactive.LoadBalancerCommand$3$1.call(LoadBalancerCommand.java:287)
	at rx.internal.util.ScalarSynchronousObservable$3.call(ScalarSynchronousObservable.java:231)
	at rx.internal.util.ScalarSynchronousObservable$3.call(ScalarSynchronousObservable.java:228)
	at rx.Observable.unsafeSubscribe(Observable.java:10327)
	at rx.internal.operators.OnSubscribeConcatMap$ConcatMapSubscriber.drain(OnSubscribeConcatMap.java:286)
	at rx.internal.operators.OnSubscribeConcatMap$ConcatMapSubscriber.onNext(OnSubscribeConcatMap.java:144)
	at com.netflix.loadbalancer.reactive.LoadBalancerCommand$1.call(LoadBalancerCommand.java:185)
	at com.netflix.loadbalancer.reactive.LoadBalancerCommand$1.call(LoadBalancerCommand.java:180)
	at rx.Observable.unsafeSubscribe(Observable.java:10327)
	at rx.internal.operators.OnSubscribeConcatMap.call(OnSubscribeConcatMap.java:94)
	at rx.internal.operators.OnSubscribeConcatMap.call(OnSubscribeConcatMap.java:42)
	at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48)
	at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30)
	at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48)
	at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30)
	at rx.Observable.subscribe(Observable.java:10423)
	at rx.Observable.subscribe(Observable.java:10390)
	at rx.observables.BlockingObservable.blockForSingle(BlockingObservable.java:443)
	at rx.observables.BlockingObservable.single(BlockingObservable.java:340)
	at com.netflix.client.AbstractLoadBalancerAwareClient.executeWithLoadBalancer(AbstractLoadBalancerAwareClient.java:112)
	at org.springframework.cloud.openfeign.ribbon.LoadBalancerFeignClient.execute(LoadBalancerFeignClient.java:83)
	at feign.SynchronousMethodHandler.executeAndDecode(SynchronousMethodHandler.java:108)
	... 136 more

找不到原因，是突然不行的，之前好好的，看了几个小时，权限什么都检查了。还是一直报。

只好认真看看错误信息，调试一下feign里报错的那行代码，如图：

点进去断点，调试，数据和请求地址，参数都对，如下图：

然后执行放过到下一步，就看到302重定向信息，如下图：

其中有个重定向地址错了：http://null/g-pc/login/toLogin?userType=0，原来是feign调用的目标服务有个过滤器，发现token为空或不可用就重定向到登录页。终于找到问题的根源了。。

feign和熔断器好用，但总是不把简单的错误信息告诉我们，害我们总在猜测中解决问题，看来出了feign问题还是最好像这样调试它的代码方能快速解决问题