How to read the second column in a large file

Question

I have a huge file with millions of columns, splited by space, but it only has a limited number of rows:

examples.txt:

1 2 3 4 5 ........
3 1 2 3 5 .........
l 6 3 2 2 ........

Now, I just want to read in the second column:

2
1
6

How do I do that in java with high performance.

Thanks

Update: the file is usually 1.4G containing hundreds of rows.

Answer 1

If your file is not statically structured, your only option is the naive one: read through the file byte sequence by byte sequence looking for newlines and grab the second column after each one. Use FileReader.

If your file were statically structured, you could calculate where in the file the second column would be for a given line and seek() to it directly.