Hi Jonathan (at school),
You need to open the file and use the readLine method to read each line... put the following in a try..catch block
String filename = "somefile.txt";
FileInputStream fin = new FileInputStream(filename);
DataInputStream myInput = new DataInputStream(fin);
while ((thisLine = myInput.readLine()) != null) { // while loop begins here
// inside the loop, you can either out.println(), or append to a string, or do whatever you want with each line
} // while