The assignment requires writing four methods in Java: arrayBuilder, writeArray, readFile, and main. The arrayBuilder method takes an integer parameter and returns an array of Strings, throwing an Exception if the parameter is negative. The writeArray method writes an array of Strings to a text file named using the provided fileName parameter. The readFile method reads a text file and populates an ArrayList with each line in the file. Finally, the main method calls these methods in sequence: calling arrayBuilder to create an array, writing it to a file using writeArray, reading the file back into an ArrayList using readFile, and printing its contents.