/*	RemoteFileCopy.java
*	@author: Charles Bell
*	@version: May 24, 2002
*	Java program which copies a file from a remote location 
*	on the Internet to a users local hard drive.
*/

import java.awt.*;
import java.io.*;
import java.net.*;
import javax.swing.*;

/**	This Java program copies a file from a remote location 
*	on the Internet to a users local hard drive. The File to copy
*	is designated as an argument either to the run option or the default
*	Constructor which takes a String argument of rthe URL to copy from.
*	The interface brings up a SaveAs FileDialog to prompt the user for a 
*	file nmae to save it to with the file name defaulted to the filename
*	associated with the URL. This provdes the user with the flexibility to
*	change the filename as desired.
*/
public class RemoteFileCopy extends JFrame{
	
	private String urlstring;

	/**	Constructor needs a String to construct a URL from as a minimum.
	*/
	RemoteFileCopy(String urlstring){
		super("RemoteFileCopy");
		this.urlstring = urlstring;
		copy(urlstring);
	}
	
	/**	Instantiates an instance of this class and class the copy method.
	*	Checks to ensure that one String argument is present.
	*/
	public static void main(String[] args){
		if (args.length != 1){		
			System.out.println("Useage: java RemoteFileCopy urlstring");
		}else if (args.length == 1){
			RemoteFileCopy remoteCopier = new RemoteFileCopy(args[0]);
			System.exit(0);
		}
	}

	/**	Copies the file associated with the urlstring argument to the local 
	*	hard drive with the filename selected by the user as a result of a
	*	SaveAs FileDialog action.
	*/
	public void copy(String urlstring){
		
		FileOutputStream fos = null;
		DataInputStream dis = null;
		
		try{
			URL url = new URL(urlstring);
			//get the filename from the URL
			String urlfilename = url.getFile();
			if (urlfilename.indexOf("/") >= 0){
				urlfilename = urlfilename.substring(urlfilename.lastIndexOf("/")+1);
			}
			URLConnection connection = url.openConnection();
			dis = new DataInputStream(connection.getInputStream());
			//bring up a SaveAs FileDialog
			File currentDirectory = new File(".");
			JFileChooser chooser = new JFileChooser();
			chooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
			chooser.setCurrentDirectory(currentDirectory);
			chooser.setSelectedFile(new File(urlfilename));
			int returnvalue = chooser.showSaveDialog(new JFrame());
			if (returnvalue == JFileChooser.APPROVE_OPTION) { 
				File selectedFile = chooser.getSelectedFile();
				fos = new FileOutputStream(selectedFile);
				while (true){
					fos.write(dis.readByte());
				}
			}
		}catch(NullPointerException npe){
			System.out.println("You must enter a filename to save your file to. ");
		}catch(EOFException eofe){
			try{
				//This ensures the streams are closed properly
				dis.close();
				fos.close();
			}catch(IOException ioe){
				System.out.println("IOException: " + ioe.getMessage());
			}
		}catch(MalformedURLException murle){
			System.err.println("MalformedURLException: " + murle.getMessage());
		}catch(IOException ioe){
			System.err.println("IOException: " + ioe.getMessage());
		}
	}
}