Everything In ArrayList Written Twice

I am trying to read a file into an array list, change some things about it, and then write it to another file. Files are getting written with what was read repeating a second time. I've tested the read method by having it print everything which goes into the ArrayList object. I then did the same with the write method which seems to write everything twice, as if everything is in the ArrayList twice, but I'm not sure how this is possible, since the read clearly did everything only once. Perhaps the ArrayList isn't the best collection to use for this purpose.

The read method:

Java Code:

private ArrayList<String> read(File in) {
String line;
ArrayList<String> data = new ArrayList<String>();
try {
BufferedReader r = new BufferedReader(new FileReader(in));

[code]....