#17 supportsMethod check not strict enough

[Anonymous]

C3P0ImplUtils.supportsMethod(...) returning true does
not guarantee that the method is supported. In
particular, when using the jconn2.jar (5.5) and Sybase
12.5, setTypeMap() is not actually supported and will
throw an UnsupportedOperationException.

I have attached my fix, which attempts to call the
getter and setter of the property. Note that it hasn't
been rigorously tested, and I'm not sure what the
performance penalties are with this kind of checking.

As a design note, the the supportsMethod information
probably shouldn't be associated with the connection
(as in NewPooledConnection) but should be associated
with the pool of connections - so you only need to
establish method support per pool, rather than per
physical connection.

[Nobody/Anonymous]

C3P0ImplUtils modification

[Steve Waldman]

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I'm sorry for the very long delay, c3p0 fixes had to take a hiatus. You are very
right that the supportsXXX methods only do a trivial check -- they test whether
an object claims to support, not whether it actually supports the method. I
prefer to leave this convention alone, but I've added extra testing elsewhere to
prevent c3p0 from erroneously calling commonly unsupported methods. There's
something of a fix to this in 0.9.0.2, but that introduced problems for some
users, a hopefully better resolution will be in 0.9.0.3 very shortly.

[Steve Waldman]

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although the supportsXXX methods are still a trivial test (does the method
exist?) c3p0 no longer calls the problematic methods even where drivers appear
to implement them. thanks again, very much, for the report and proposed fix.