import java.io.*;

public class CopyFile{
	private static void copyfile(String srFile, String dtFile){
		try{
			File f1 = new File(srFile);
			File f2 = new File(dtFile);
			InputStream in = new FileInputStream(f1);
			
			//For Append the file.
//			OutputStream out = new FileOutputStream(f2,true);

			//For Overwrite the file.
			OutputStream out = new FileOutputStream(f2);

			byte[] buf = new byte[1024];
			int len;
			while ((len = in.read(buf)) > 0){
				out.write(buf, 0, len);
			}
			in.close();
			out.close();
			System.out.println("File copied.");
		}
		catch(FileNotFoundException ex){
			System.out.println(ex.getMessage() + " in the specified directory.");
			System.exit(0);
		}
		catch(IOException e){
			System.out.println(e.getMessage());			
		}
	}
	public static void main(String[] args){
		switch(args.length){
			case 0: System.out.println("File has not mentioned.");
					System.exit(0);
			case 1: System.out.println("Destination file has not mentioned.");
					System.exit(0);
			case 2: copyfile(args[0],args[1]);
					System.exit(0);
			default : System.out.println("Multiple files are not allow.");
					  System.exit(0);
		}
	}
}