I currently have a table in oracle which I have created, but need to take a text file (which I have used a fileChooser for) and then use this file to update the records in the oracle database. How would I go about this?

Thanks.

Read the file for its data.
Then use that data to query the database: Run an UPDATE to record you want to update.

Learn how to read files.
Learn SQL.
Learn how to run queries with java.

You need a update statement to update your table in oracle. See below for "Update" syntax:
UPDATE table
SET column = expression
WHERE predicates;

Also you google to find "update", you will find a lot of examples. :-) .

thanks. i heard something about arrays, so i need to set the data from the text file as arrays, if so, how?

Whether you use arrays, Lists, or whatever, the point is still the same. You'll need to read the file content into some structure and then use JDBC to update/insert your table values.