2.x: SEVERE log statement for a handled problem

[tomas-langer]

Helidon SE
Reported for 2.6.0 (not tested yet against newer versions)

Follow up for #7053 for logging an error even though the problem is handled.

In a simple web server (such as the bare-se generated from Helidon CLI), when the following request is sent:

curl -i -H "Content-Type: %{bad-actor}" http://localhost:8080/greet

The server always prints the following log stement:

SEVERE io.helidon.webserver.RequestRouting Thread[nioEventLoopGroup-3-1,10,main]: Unexpected error occurred during routing!
java.lang.IllegalArgumentException: Could not parse '%{bad-actor}'
	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$3(ForwardingHandler.java:166)
	at io.helidon.common.context.Contexts.runInContext(Contexts.java:137)
	at io.helidon.webserver.ForwardingHandler.channelRead0(ForwardingHandler.java:165)
	at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:99)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)
	at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:346)
	at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:318)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)
	at io.netty.channel.DefaultChannelPipeline$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)

This is wrong, as the error is handled (by default or custom DirectHandler).
We should switch the log level, or remove it and only log on the place where we are 100% sure nobody else will take care of the exception

[Captain1653]

@danielkec The PR for this issue was already merged, but the issue wasn't closed because Fixes-notations works only for main branch. Should this issue be closed?

And the same for the #8029