ArrayList - Intersection Between Lines Of Data

My code is like follows. I want add the lines of data from text file to arraylist.After add the lines to array list,i want to get the interesection between the lines of data. But I could not get the intersection and it returns empty. My sample data from specific line in text file as follows,

line 1 data:5 1 1 1 2 1 3 1 1
line 2 data:5 4 4 5 7 10 3 2 1

try {
File f1 = new File("C:/users/User1/Desktop/Datasets/Dataset.txt");
String filename = f1.getAbsolutePath();
FileReader reader = new FileReader(filename);
BufferedReader br1 = new BufferedReader(reader);

[Code] .....