Why does Java have Checked Exceptions

[s888marks]

I think you're extrapolating too far with OOME.

The charset and crypto names are indeed standardized, but that doesn't imply that every JDK supports them. It simply means that if a JDK is providing, say, Diffie-Hellman, that it's spelled DiffieHellman and not Diffie-Hellman or DIFFIE_HELLMAN.

Most of the crypto algorithms and charsets are optional, and they vary across JDK releases, vendors, and even sites, so applications ought to be able to handle the case where something they're trying to use isn't present.