We had a meeting on this a while back, but I'm going to file a bug on it as we are running into this problem more and more.
The basic problem is that when Swing gets a KeyTyped event we have no way of knowing if it is a valid key combination, or perhaps the only way to type the key. For example, pressing Ctrl-c results in a KeyTyped with a 'c' char and CTRL modifier. Typically you don't want such key sequences to appear in a text widgets, and thus we filter them. We also filter Alt keys for the same reason. The problem then comes that in some locales and some keyboards you need to type alt to produce certain characters. Since we filter these out, the user can then no longer enter these characters.

. Don't produce KeyTyped events unless this is the only way to enter the character.
. Provide some API to determine if this is the only way to enter the character.