How can I read a large text file line by line using Java?

Question

I need to read a large text file of around 5-6 GB line by line using Java.

How can I do this quickly?

Answer 1

In Java 8, you could do:

try (Stream lines = Files.lines (file, StandardCharsets.UTF_8))
{
    for (String line : (Iterable) lines::iterator)
    {
        ;
    }
}

Some notes: The stream returned by Files.lines (unlike most streams) needs to be closed. For the reasons mentioned here I avoid using forEach(). The strange code (Iterable) lines::iterator casts a Stream to an Iterable.