Interesting - you are getting an out of memory on a readline. At a guess, you are reading in a big file without linebreaks.
Instead of using readline to get the stuff out of the file as one single big long string, write stuff that understands the input a bit better, and handles it in chunks.
If you simply must have the whole file in a single big long string ... well, get better at coding. In general, trying to handle mutimegabyte data by stuffing it all into a single array of byte (or whatever) is a good way to lose.
Go have a look at CharacterSequence.
