How do I input a text file directly into Java?

Question

I heard something like this

java myMainClass < myInputFile.txt

will provide a file as input to my Java program.

But how do I access that input?

Answer 1

That command is piping the file into STDIN, which in Java you can access as System.in.

For example, if you want to use a Scanner:

Scanner input = new Scanner(System.in);