Fwd: RFR(m): 8140281 deprecate Optional.get()

Stuart Marks stuart.marks at oracle.com
Mon Apr 25 23:37:14 UTC 2016

On 4/25/16 4:27 PM, Jonathan Gibbons wrote:
> Enter.java:
> It's pretty ugly that the recommended usage is to have to add a SuppressWarnings
> for a reasonable and valid use of Optional.get.
> Are you sure this is the API you want?

Ah, I had neglected to explain this one, sorry.

In the majority cases, uses of get() can be refactored away to use one of the 
other Optional methods.

In just about all the remaining cases, the code should use the replacement 
method getWhenPresent(), which has the same semantics as the current get() call. 
This is called for if lambdas should be avoided because of startup performance, 
or because of checked exceptions, or if it's provable from context that a value 
is always present.

The case of Enter.java is a special one; it gets compiled with the boot 
libraries (JDK 8) and getWhenPresent() doesn't exist in those. It doesn't 
generate a warning though. But as you explained to me the other day, this code 
is later recompiled against the JDK 9 libraries, and in that case it does 
generate the warning.

So for this case I think calling get() with @SuppressWarnings is the way to 
proceed. I opted to extract a local variable and put @SW on it, in order to 
minimize its scope, but if you prefer an alternative I'd be happy to change it.


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