Yes, such stuff can be done as optimization. But we have to do
this carefully. We have to make sure this can be exploited by bad
code. I would guess the current code can be exploited. I need to
write some applets to test this.
I think this approach would be safer, because the open method i
mentioned can (and should) be package protected. The current
FileChannelImpl is public, so everyone can access it.
About the optimization, i consider it necessary when i want to use
classpath out of the box, since i'm not supporting native methods.