Please UseAMeaningfulSubjectLine. You've already made two threads with the same title "FILE I/O". This doesn't tell anything about your problem. You can click the "edit" button of your first post to correct the title.
Have you looked at the java.io.File documentation?
"Any fool can write code that a computer can understand. Good programmers write code that humans can understand." --- Martin Fowler
Please correct my English.
In addition, you might want to read the javadoc on likely classes before posting a question -- such as the mkdir() and mkdirs() methods on java.io.File.
rc
Don't get me started about those stupid light bulbs.