netty5/handler
Norman Maurer 6ac8ef54f7
Remove throws Exception from ChannelHandler methods that handle o… (#11417)
Motivation:

At the moment all methods in `ChannelHandler` declare `throws Exception` as part of their method signature. While this is fine for methods that handle inbound events it is quite confusing for methods that handle outbound events. This comes due the fact that these methods also take a `ChannelPromise` which actually need to be fullfilled to signal back either success or failure. Define `throws...` for these methods is confusing at best. We should just always require the implementation to use the passed in promise to signal back success or failure. Doing so also clears up semantics in general. Due the fact that we can't "forbid" throwing `RuntimeException` we still need to handle this in some way tho. In this case we should just consider it a "bug" and so log it and close the `Channel` in question. The user should never have an exception "escape" their implementation and just use the promise. This also clears up the ownership of the passed in message etc.

As `flush(ChannelHandlerContext)` and `read(ChannelHandlerContext)` don't take a `ChannelPromise` as argument this also means that these methods can never produce an error. This makes kind of sense as these really are just "signals" for the underlying transports to do something. For `RuntimeException` the same rule is used as for other outbound event handling methods, which is logging and closing the `Channel`.

Motifications:

- Remove `throws Exception` from signature
- Adjust code to not throw and just notify the promise directly
- Adjust unit tests

Result:

Much cleaner API and semantics.
2021-07-08 10:16:00 +02:00
..
src Remove throws Exception from ChannelHandler methods that handle o… (#11417) 2021-07-08 10:16:00 +02:00
pom.xml Use http in xmlns URIs to make maven release plugin happy again (#10788) 2020-11-10 10:51:05 +01:00