Question

How we can take input from the file in the Eclipse?
Just like we direct the I/O from the file from the command line.
java MyProgram < input.txt >output.txt
I am unable to direct the input.
but output directing is easy.
Just go->Run->Run->Configurations->Common

Answer 1

If you need necessarily use the default in you can do something like this:

System.setIn(new FileInputStream("testFile.txt"));

a sample of how it works follows:

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;

public class TestSystemIn {

    public static void main(final String[] args) throws IOException {
        // prepare test
        FileOutputStream fos = new FileOutputStream("testFile.txt");
        fos.write("testToken".getBytes());

        // configure env
        System.setIn(new FileInputStream("testFile.txt"));

        // perform read test
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        System.out.println("read: " + br.readLine());
    }

}

The output could be done in the same way using:

System.setOut(new PrintStream("testFile.txt"));