1. 2018-09-04 19:27:48.860 ERROR 349 --- [reactor-http-client-epoll-8] c.pearson.ltg.book.services.BookService  : | onError(org.springframework.web.reactive.function.client.WebClientResponseException: ClientResponse has erroneous status code: 400 Bad Request)
2. 2018-09-04 19:27:48.861 ERROR 349 --- [reactor-http-client-epoll-8] c.pearson.ltg.book.services.BookService  :
3.  
4. org.springframework.web.reactive.function.client.WebClientResponseException: ClientResponse has erroneous status code: 400 Bad Request
5.         at org.springframework.web.reactive.function.client.DefaultWebClient$DefaultResponseSpec.lambda$createResponseException$7(DefaultWebClient.java:472)
6.         at reactor.core.publisher.FluxMap$MapSubscriber.onNext(FluxMap.java:100)
7.         at reactor.core.publisher.FluxDefaultIfEmpty$DefaultIfEmptySubscriber.onNext(FluxDefaultIfEmpty.java:92)
8.         at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onNext(FluxMapFuseable.java:115)
9.         at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onNext(FluxMapFuseable.java:115)
10.         at reactor.core.publisher.FluxFilterFuseable$FilterFuseableSubscriber.onNext(FluxFilterFuseable.java:104)
11.         at reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1073)
12.         at reactor.core.publisher.MonoCollectList$MonoBufferAllSubscriber.onComplete(MonoCollectList.java:117)
13.         at reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:130)
14.         at reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:130)
15.         at reactor.ipc.netty.channel.FluxReceive.terminateReceiver(FluxReceive.java:377)
16.         at reactor.ipc.netty.channel.FluxReceive.drainReceiver(FluxReceive.java:202)
17.         at reactor.ipc.netty.channel.FluxReceive.onInboundComplete(FluxReceive.java:342)
18.         at reactor.ipc.netty.channel.ChannelOperations.onInboundComplete(ChannelOperations.java:336)
19.         at reactor.ipc.netty.channel.ChannelOperations.onHandlerTerminate(ChannelOperations.java:403)
20.         at reactor.ipc.netty.http.client.HttpClientOperations.onInboundNext(HttpClientOperations.java:601)
21.         at reactor.ipc.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:136)
22.         at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
23.         at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
24.         at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
25.         at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:102)
26.         at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
27.         at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
28.         at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
29.         at io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:438)
30.         at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:310)
31.         at io.netty.handler.codec.ByteToMessageDecoder.channelInputClosed(ByteToMessageDecoder.java:371)
32.         at io.netty.handler.codec.ByteToMessageDecoder.channelInactive(ByteToMessageDecoder.java:342)
33.         at io.netty.handler.codec.http.HttpClientCodec$Decoder.channelInactive(HttpClientCodec.java:282)
34.         at io.netty.channel.CombinedChannelDuplexHandler.channelInactive(CombinedChannelDuplexHandler.java:223)
35.         at io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:245)
36.         at io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:231)
37.         at io.netty.channel.AbstractChannelHandlerContext.fireChannelInactive(AbstractChannelHandlerContext.java:224)
38.         at io.netty.handler.codec.ByteToMessageDecoder.channelInputClosed(ByteToMessageDecoder.java:377)
39.         at io.netty.handler.codec.ByteToMessageDecoder.channelInactive(ByteToMessageDecoder.java:342)
40.         at io.netty.handler.ssl.SslHandler.channelInactive(SslHandler.java:1028)
41.         at io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:245)
42.         at io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:231)
43.         at io.netty.channel.AbstractChannelHandlerContext.fireChannelInactive(AbstractChannelHandlerContext.java:224)
44.         at io.netty.channel.DefaultChannelPipeline$HeadContext.channelInactive(DefaultChannelPipeline.java:1429)
45.         at io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:245)
46.         at io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:231)
47.         at io.netty.channel.DefaultChannelPipeline.fireChannelInactive(DefaultChannelPipeline.java:947)
48.         at io.netty.channel.AbstractChannel$AbstractUnsafe$8.run(AbstractChannel.java:822)
49.         at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:163)
50.         at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:404)
51.         at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:309)
52.         at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:886)
53.         at java.lang.Thread.run(Thread.java:748)