Exception accessing static resources in Spring Web Reactive with Netty [SPR-14975]

[spring-projects-issues]

Daniel Fernández opened SPR-14975 and commented

Scenario

A Spring Web Reactive application (5.0.0.BUILD-SNAPSHOT) using Spring Boot (2.0.0.BUILD-SNAPSHOT) and running on a Netty server, contains a static resource at its /src/main/resources/static/images folder.

This resource is accessed from a browser or curl, like:

$ curl http://localhost:8080/images/logo.png

Observed Results

An exception is thrown:

2016-12-03 17:55:34.082 ERROR 14751 --- [ctor-http-nio-2] o.s.w.s.h.ExceptionHandlingWebHandler    : Could not complete request

io.netty.handler.codec.EncoderException: java.lang.IllegalStateException: unexpected message type: DefaultFileRegion
	at io.netty.handler.codec.MessageToMessageEncoder.write(MessageToMessageEncoder.java:106) ~[netty-all-4.1.6.Final.jar:4.1.6.Final]
	at io.netty.channel.CombinedChannelDuplexHandler.write(CombinedChannelDuplexHandler.java:345) ~[netty-all-4.1.6.Final.jar:4.1.6.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:749) ~[netty-all-4.1.6.Final.jar:4.1.6.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:741) ~[netty-all-4.1.6.Final.jar:4.1.6.Final]
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:827) ~[netty-all-4.1.6.Final.jar:4.1.6.Final]
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:734) ~[netty-all-4.1.6.Final.jar:4.1.6.Final]
	at io.netty.channel.ChannelDuplexHandler.write(ChannelDuplexHandler.java:106) ~[netty-all-4.1.6.Final.jar:4.1.6.Final]
	at io.netty.handler.codec.http.HttpServerKeepAliveHandler.write(HttpServerKeepAliveHandler.java:87) ~[netty-all-4.1.6.Final.jar:4.1.6.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:749) ~[netty-all-4.1.6.Final.jar:4.1.6.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:741) ~[netty-all-4.1.6.Final.jar:4.1.6.Final]
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:827) ~[netty-all-4.1.6.Final.jar:4.1.6.Final]
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:734) ~[netty-all-4.1.6.Final.jar:4.1.6.Final]
	at io.netty.channel.ChannelDuplexHandler.write(ChannelDuplexHandler.java:106) ~[netty-all-4.1.6.Final.jar:4.1.6.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:749) ~[netty-all-4.1.6.Final.jar:4.1.6.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeWriteAndFlush(AbstractChannelHandlerContext.java:812) ~[netty-all-4.1.6.Final.jar:4.1.6.Final]
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:825) ~[netty-all-4.1.6.Final.jar:4.1.6.Final]
	at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:805) ~[netty-all-4.1.6.Final.jar:4.1.6.Final]
	at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:842) ~[netty-all-4.1.6.Final.jar:4.1.6.Final]
	at io.netty.channel.DefaultChannelPipeline.writeAndFlush(DefaultChannelPipeline.java:1032) ~[netty-all-4.1.6.Final.jar:4.1.6.Final]
	at io.netty.channel.AbstractChannel.writeAndFlush(AbstractChannel.java:296) ~[netty-all-4.1.6.Final.jar:4.1.6.Final]
	at reactor.ipc.netty.channel.ChannelOperations.lambda$sendFile$3(ChannelOperations.java:363) ~[reactor-netty-0.6.0.BUILD-SNAPSHOT.jar:na]
	at reactor.core.publisher.MonoUsing.subscribe(MonoUsing.java:83) ~[reactor-core-3.0.3.RELEASE.jar:na]
	at reactor.core.publisher.FluxConcatIterable$ConcatIterableSubscriber.onComplete(FluxConcatIterable.java:152) ~[reactor-core-3.0.3.RELEASE.jar:na]
	at reactor.core.publisher.FluxConcatIterable.subscribe(FluxConcatIterable.java:69) ~[reactor-core-3.0.3.RELEASE.jar:na]
	at reactor.core.publisher.MonoNext.subscribe(MonoNext.java:41) ~[reactor-core-3.0.3.RELEASE.jar:na]
	...
Caused by: java.lang.IllegalStateException: unexpected message type: DefaultFileRegion
	at io.netty.handler.codec.http.HttpObjectEncoder.encode(HttpObjectEncoder.java:97) ~[netty-all-4.1.6.Final.jar:4.1.6.Final]
	at io.netty.handler.codec.MessageToMessageEncoder.write(MessageToMessageEncoder.java:88) ~[netty-all-4.1.6.Final.jar:4.1.6.Final]
	... 109 common frames omitted

Example Application

Please find a very simple example application for reproducing this issue here: https://github.com/danielfernandez/test-spring-boot-reactive-static-netty

---

Affects: 5.0 M3

Reference URL: https://github.com/danielfernandez/test-spring-boot-reactive-static-netty

Referenced from: commits ba47d06, 953f7d4

0 votes, 5 watchers

[spring-projects-issues]

Brian Clozel commented

I've reported this issue against reactor-netty with additional details. This seems to also impact the reactor-netty HTTP client which powers our WebClient.

[spring-projects-issues]

Rossen Stoyanchev commented

I've temporarily filtered out Reactor Netty for the two hanging tests so we can get snapshots going again.