Error handling of invalid content-type

[janotav]

Environment Details

• Helidon Version: 2.6.0
• Helidon SE
• JDK version: 17
• OS: Linux
• Docker version (if applicable):

---

Problem Description

Sending POST request with invalid content-type %{bad actor}

Leads to java.lang.IllegalArgumentException in the server log and on the client side the observed behaviour is:

• 400 Bad Request
• content: Could not parse '%{bad actor}'

Expected behaviour

We would like to:

• be able to control response status & content
• avoid Unexpected error occurred during routing! exception in our server log

Is that currently possible? If not, can this be added?

[tomas-langer]

To create a custom response for "pre-routing" errors, such as bad request, you can add a DirectHandler.
See WebServer.Builder.directHandler(DirectHandler handler, DirectHandler.EvenType... types)

You direct hanlder will get as much information as could be retrieved from the request, and you can create a customized response to be sent back.

[tomas-langer]

For the part about not seeing the error in your logs, could you share the stacktrace of that exception please (I plan to split it into a new issue, so if you are OK with creating a new issue specifically for the error in the logs, it would be nice).

Thanks

[janotav]

Here is full stack:

java.lang.IllegalArgumentException: Could not parse '%{#context['com.opensymphony.xwork2.dispatcher.HttpServletResponse'].addHeader('X-Tenable','rtgKIzqK')}.multipart/form-data'
at io.helidon.common.http.MediaType.parse(MediaType.java:360)
at java.base/java.util.Optional.map(Optional.java:260)
at io.helidon.webserver.HashRequestHeaders.contentType(HashRequestHeaders.java:82)
at io.helidon.webserver.Request.<init>(Request.java:90)
at io.helidon.webserver.RequestRouting$RoutedRequest.<init>(RequestRouting.java:255)
at io.helidon.webserver.RequestRouting.route(RequestRouting.java:86)
at io.helidon.webserver.ForwardingHandler.lambda$channelReadHttpRequest$17(ForwardingHandler.java:470)
at io.helidon.webserver.RequestContext.lambda$runInScope$4(RequestContext.java:77)
at io.helidon.common.context.Contexts.runInContext(Contexts.java:117)
at io.helidon.webserver.RequestContext.runInScope(RequestContext.java:75)
at io.helidon.webserver.ForwardingHandler.channelReadHttpRequest(ForwardingHandler.java:470)
at io.helidon.webserver.ForwardingHandler.lambda$channelRead0$3(ForwardingHandler.java:166)
at io.helidon.common.context.Contexts.runInContext(Contexts.java:137)
at io.helidon.webserver.ForwardingHandler.channelRead0(ForwardingHandler.java:165)
at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:99)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:346)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:318)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)
at io.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1373)
at io.netty.handler.ssl.SslHandler.decodeJdkCompatible(SslHandler.java:1236)
at io.netty.handler.ssl.SslHandler.decode(SslHandler.java:1285)
at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:529)
at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:468)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:290)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:440)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166)
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:788)
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:724)
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:650)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:562)
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997)
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.base/java.lang.Thread.run(Thread.java:833) Caused by: java.lang.IllegalStateException: Unexpected character: /
at io.helidon.common.http.Tokenizer.checkState(Tokenizer.java:173)
at io.helidon.common.http.Tokenizer.consumeCharacter(Tokenizer.java:109)
at io.helidon.common.http.MediaType.parse(MediaType.java:326) ... 44 more

[tomas-langer]

Example of a direct handler that maps bad requests to not found:

DirectHandler badRequestHandler = (transportRequest, eventType, responseStatus, message) -> DirectHandler.TransportResponse.builder()
                .status(Http.Status.NOT_FOUND_404)
                .entity("Endpoint not found")
                .build();

The exception is still written to the log, As that error is handled elsewhere, the message should not be printed. I will create an issue for it.

[tomas-langer]

Submitted an issue for the logging problem. I will close this one as I have answered how to customize the response for bad requests.