InputSource.java

import java.util.*;
import java.io.*;

// A class that generates lines from the input.

public class InputSource {

    private BufferedReader in;

    public InputSource ( ) {
		try {
			in = new BufferedReader (new InputStreamReader (System.in));
		} catch (Exception e) {
			System.err.println ("Couldn't access keyboard!");
			System.exit (1);
		}
    }
    
    public InputSource (String fileName) {
		try {
			in = new BufferedReader (new InputStreamReader (new FileInputStream (fileName)));
		} catch (Exception e) {
			System.err.println ("Couldn't access file!");
			System.exit (1);
		}
    }
	
    public String readLine ( ) {
		String line = "";
		try {
			line = in.readLine ( );
		} catch (IOException e) {
			System.err.println ("input error");
			System.exit (1);
		}
		if (line == null) {
			return null;
		}
		// Added call to trim: March 18, 2011.
		return line.toLowerCase ( ).trim ( );
    }
    
    public static void main (String [ ] args) {
    	InputSource in;
    	if (args.length == 0) {
    		in = new InputSource ( );
    	} else {
    		in = new InputSource (args[0]);
    	}
    	String s;
    	while (true) {
    		s = in.readLine ( );
    		if (s == null) {
    			System.exit (0);
    		}
    		System.out.println (s);
    	}
    }
}