Wonder how many more topics you are going to come with! just kidding. I agree that the topics you mentioned are a little boring. I/O is very important though. The topics you have to cover in I/O are, text representation in
java, File class, RamdomAccessFile Class, InputStreams, Outputstreams , Readers and Writers. There is a repeatition of a lot of things. Eg. if you read inputstreams then outputstream shouldn't take you long. Same with Readers and writers. You might be able to cover all this in less than and hour.