File.setReadonly(true) doesn’t actually work on windows (at least on the JDK that we’re working on). According to the bug report filed here, it is just setting the DOS flag that prevents it from being deleted just not being written to.
Meanwhile, assuming you have mounted a read only disk partition in windows to, say X:, new File(“X:/”).canWrite() returns true when it really should be returning false. I’m still trying to find the bug reported to sun for this, or will later update this entry to include it. It seems to persist when running against both jdk1.5.0_15 and jdk1.6.0_07.
