/*
    DemoFileReader.java
    2013-11-22
    David G. Klick
    
    Demonstrates the use of the File, FileReader,
    and FileWriter objects.
*/
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Scanner;

public class DemoFileReader {
    public static void main(String[] args) {
        Scanner kbd = new Scanner(System.in);
        String source, destination;
        File sourceFile, destinationFile;

        System.out.print("This program copies a file");

        // get name of source file and check it out
        System.out.print("Enter name of source file: ");
        source = kbd.nextLine();
        if (source.length() == 0) {
            System.out.println("Error: No source file name was entered");
            System.exit(1);
        }
        sourceFile = new File(source);
        if (!sourceFile.exists()) {
            System.out.println("Error: Source file does not exist");
            System.exit(1);
        }
        if (!sourceFile.isFile()) {
            System.out.println("Error: Source file is not a regular file");
            System.exit(1);
        }
        if (!sourceFile.canRead()) {
            System.out.println("Error: Source file is not readable");
            System.exit(1);
        }

        // get name of destination file and check it out
        System.out.print("Enter name of destination file: ");
        destination = kbd.nextLine();
        if (destination.length() == 0) {
            System.out.println("Error: No destination file name was entered");
            System.exit(1);
        }
        destinationFile = new File(destination);
        if (destinationFile.exists()) {
            System.out.println("Error: Destination file already exists");
            System.exit(1);
        }

        // copy file using FileReader and FileWriter
        // Note: This try/catch block is not a good example of how
        //     to handle file exceptions, but it will work for this
        //     simple program. For example, an error in reading or
        //     writing would trigger an exception and leave both
        //     files open. The complex code needed to check for
        //     all possibilities has been omitted here. Java 7 has
        //     better features for dealing with this problem - but
        //     this example was made to run on Java 6 if needed.
        try {
            FileReader inFile = new FileReader(sourceFile);
            FileWriter outFile = new FileWriter(destinationFile);
            int ch;
            while ((ch = inFile.read()) != -1) outFile.write(ch);
            inFile.close();
            outFile.close();
        } catch (FileNotFoundException e1) {
            System.out.println("Error: Source file not found when starting copy");
        } catch (IOException e2) {
            System.out.println("Error: An I/O error has occurred during the copy");
        }
    }
}