RFR: 7198: add websocket server that pushes data on selection updates [v8]

[Alex Ciminian]

On Wed, 27 Oct 2021 15:10:09 GMT, Alex Macdonald <aptmac at openjdk.org> wrote:

>> Alex Ciminian has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Fix websocket UI messages and copyright notices
>
> Taking a closer look at the error, it seems to be complaining that it can't find the required asm version for spifly.
> 
>  Unresolved requirement: Require-Capability: osgi.extender; filter:="(osgi.extender=osgi.serviceloader.registrar)"; resolution:="optional"
>    -> Provide-Capability: osgi.extender; osgi.extender="osgi.serviceloader.registrar"; version:Version="1.0.0"
>       org.apache.aries.spifly.dynamic.bundle [15]
>         Unresolved requirement: Import-Package: org.objectweb.asm; version="[9.2.0,10.0.0)"
> 
> 
> Taking a look at the 2021-06 target (https://download.eclipse.org/releases/2021-06/202106161001/plugins/), we have access to asm 8.0.1 and 9.1.0, but spifly requires at least 9.2.0.
> 
> For the JMC-Eclipse launcher, if I add asm 9.2.0 to a list of additional plugins then everything works properly.
> ![2021-10-27-105920_912x882_scrot](https://user-images.githubusercontent.com/10425301/139093583-01aabf6c-6177-4220-88e2-8c2d53b6478e.png)
> 
> This can be verified if I disable one of the asm plugins and try to validate, Eclipse will tell me there's something missing:
> ![2021-10-27-110009_910x937_scrot](https://user-images.githubusercontent.com/10425301/139093838-6607288c-117a-44de-8f92-d6ef3e3c48f5.png)

Thanks @aptmac, this is really useful! �� 

I've updated the Eclipse launchers to include the additional `asm` plugins and now I'm no longer seeing startup errors, everything seems to work fine. I've added a commit with these changes.

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PR: https://git.openjdk.java.net/jmc/pull/306