/**
 * FileInputDemo opens a file specified as a command-line
 * argument, reads the file line by line, and prints an
 * upper-case version of the file to standard output.
 *
 * @author Jeff Ondich, 1/14/04
 */

import java.io.*;

public class FileInputDemo
{
    public static void main( String[] args )
    {
        // It's good to tell people when they are invoking the program incorrectly.
        if( args.length < 1 )
        {
            System.out.println( "Usage: java FileInputDemo someFileName" );
            System.exit( 1 );
        }

        // You need to declare and initialize the BufferedReader out here
        // so it will still be in scope after the try/catch blocks.
        BufferedReader in = null;
        try
        {
            in = new BufferedReader( new FileReader( args[0] ) );
        }
        catch( FileNotFoundException e )
        {
            System.out.println( "Can't open " + args[0] + " for reading." );
            System.out.println( "Perhaps you didn't spell the file name correctly." );
            System.exit( 1 );
        }

        // If we get here, the file is open and ready to read.
        // We'll read it by using an intentional infinite loop and
        // a "break" statement when reading fails.
        while( true )
        {
            String line = null;
            try
            {
                line = in.readLine();
            }
            catch( IOException e )
            {
                System.out.println( "Something sad occurred while reading the file.  I give up." );
                System.exit( 1 );
            }

            if( line == null )
                break;

            System.out.println( line.toUpperCase() );
        }

        // It's good to close files when you're done with them.  It
        // frees up memory and other operating system resources.
        try
        {
            in.close();
        }
        catch( IOException e )
        {
            System.out.println( "BufferedReader.close failed.  Weird." );
            System.exit( 1 );
        }
    }
}