Adds a default send(Throwable) method to ServerResponse.java as the first step in providing an easy facility for reporting exceptions during HTTP processing

[ljnelson]

This PR, when ready, will add the ability to conveniently send a Throwable during HTTP processing.

Signed-off-by: Laird Nelson laird.nelson@oracle.com

[ljnelson]

See issue #878.

[ljnelson]

• Add default void send(Throwable) method to ServerResponse
• Add ThrowableBodyWriter class that handles cases where stack traces should be output or not
• Actually, consider moving the guts of ThrowableBodyWriter into ContentWriters appropriately
• Figure out how to choose whether stack traces should be output or not, following the directive that such a choice should come from some kind of configuration (Needs separate issue and more discussion; see Provide a way to get configuration "into" MediaSupport #1392)
• Add ThrowableBodyWriter, properly configured, to the tail of MediaSupport's list of default MessageBodyWriter implementations

[tomas-langer]

I think it would be useful to have a configurable option for this writer:

• send a message (maybe also configurable) "Internal server error"
• send the stack trace across the network

Sending a stack trace by default is sometimes considered a security issue, as you leak internal information about your implementation. So it is really useful for development and troubleshooting, but should not be used in production.

[ljnelson]

Yes, the configuration will be a separate follow-on issue (see #1392), as Romain and I decided that getting configuration into MediaSupport etc. was worth its own issue. You'll notice in this PR as it stands that stack trace writing is disabled.

[ljnelson]

Thanks; I'll merge this soon and then start work on #1392.

[tomas-langer]

Thanks for explanation, approved.