Closed System.in

SystemInTest.java

import org.junit.Assert;
import org.junit.Test;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;

public class SystemInTest {
    @Test
    public void closed_system_in() throws IOException {
        ByteArrayInputStream input = new ByteArrayInputStream(new byte[0]);

        System.setIn(input);

        InputStreamReader reader = new InputStreamReader(System.in);

        Assert.assertEquals(-1, reader.read());
    }
}

Yep. I ended up here, too. It turned out not to be what I wanted to check.