On 01/18/2012 03:09 PM, Joe Darcy wrote:
1. In the new parsing methods, could the String arguments be changed
to the more general
java.lang.CharSequence? For many parsing applications, it could be
more convenient
to pass a CharSequence than to create a new String.
I don't think that would be very helpful in this case. If the methods
were changed to take a CharSequence, the first action I'd write in the
method would be to call toString on the argument; this is necessary to
guard against the class of time-of-check-versus-time-of-use problems
because the CharSequence objects can be mutable.
Though the existing methods do operate on immutable inputs, there is no
expectation of synchronization provided by the parsing methods of
Integer, etc.
Making the change would not break any existing code because it continues
to pass
immutable inputs.
New code that calls the methods using CharSequences, in full knowledge
of the
mutability of CharSequences, would manage or avoid the concurrency issues,
most likely by keeping the computation to a single thread or otherwise
synchronizing
changes to the object that implement CharSequence.
Since Integer makes no assurances about being multi-thread safe it can
operate
under those assumptions and does not need to make copies of the arguments.
In any case, the copy operation itself could run afoul of concurrency
faults, and it
doesn't matter where the copy occurs, inside or outside of the Integer
methods.
Please consider the necessity of extra steps by the developer (to
produce strings)
and the potential savings in the load on the heap by not creating copies
of strings.
Roger
