Java-Copying a file

	import java.io.*;

	public class CopyFile {
	    public static void main(String[] args) throws IOException {
	        switch (args.length) {
	            case 0:
	                System.out.println("Error in usage:");
	                System.out.println(
	                    " Usage: java CopyFile ");
	                break;
	            case 1:
	                System.out.println(
	                    "Specify the destination file.");
	                System.out.println(
	                    " Usage: java CopyFile ");
	                break;
	            case 2:
	                File sourceFile = new File(args[0]);
	                File destFile = new File(args[1]);

	                if (!sourceFile.exists()) {
	                    System.out.println(args[0] + " not found !!!");
	                    System.exit(0); // stopping application
	                }

	                if (destFile.exists()) {
	                    System.out.print(args[1] +
	                        " file already exists. Overwrite? (y/n): ");
	                    int response = System.in.read();
	                    if (response == 'N' || response == 'n') {
	                        // if you do not want to overwrite the file.
	                        System.out.print("Copy operation aborted.");
	                        System.exit(0); // stopping application
	                    }
	                }

	                System.out.println("Copying file...\n" +
	                    args[0] + " to " + args[1]);

	                FileInputStream inputFile =
	                    new FileInputStream(sourceFile);
	                FileOutputStream outputFile =
	                    new FileOutputStream(destFile);

	                //boolean arg is for "append"
	                /*FileOutputStream outputFile =
	                new FileOutputStream(destFile, true);

	                FileOutputStream outputFile =
	                new FileOutputStream(args[1]);

	                FileOutputStream outputFile =
	                new FileOutputStream(args[1], true);*/

	                byte[] inputFileData = new byte[inputFile.available()];
	                inputFile.read(inputFileData);
	                outputFile.write(inputFileData);

	                inputFile.close();
	                outputFile.close();

	                System.out.println("File successfully copied !");

	        }
	    }
	}

	File oldFile = new File("abc.txt");
	File newFile = new File("xyz.txt");
	oldFile.renameTo(newFile);

	new File("abc.txt").renameTo(new File("xyz.txt"));