File Copy by Java

import java.io.*;

public class isuru{

 public static void main(String args[]){
  if(args.length != 2){
   System.err.println("Usage: java File Copy");
  }else{
   try{
   copy(args[0], args[1]);
   }catch(IOException e){
    System.err.println(e.getMessage());
   }
  }
 }
 
 public static void copy(String from_name, String to_name) throws IOException {
 
  File from_file = new File(from_name);
  File to_file = new File(to_name);
  
  if(!from_file.exists())
   abort("No such source file: "+from_name);
  if(!from_file.isFile())
   abort("Can't copy directory: "+ from_name);
  if(!from_file.canRead())
   abort("Source file is unreadable"+from_name);
  
  //to_name
  if(!to_file.exists()){
   if(!to_file.canWrite()){
    abort("destination file is unwriteable: "+to_name);
   System.out.println("Overwrite existing file "+ to_file.getName()+"?(Y/N): ");
   System.out.flush();
   BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
   String response = in.readLine();
   if(!response.equals("Y") && !response.equals("y"))
    abort("existing file was not overwritten! ");
   
   }
  }else{
   String parent = to_file.getParent();
   if(parent == null)
    parent = System.getProperty("user.dir");
   File dir = new File(parent);
   if(!dir.exists())
    abort("destination directory doesn't exist: "+parent);
   if(dir.isFile())
    abort("destination is not a directory: "+parent);
   if(!dir.canWrite())
    abort("destination directory is unwritable "+parent);
  }
  
  FileInputStream from = null;
  FileOutputStream to = null;
  
  try{
   from = new FileInputStream(from_file);
   to = new FileOutputStream(to_file);
   byte[] buffer = new byte[4096];
   int bytes_read;
    while((bytes_read = from.read(buffer)) != -1)
    to.write(buffer,0, bytes_read);
  }finally{
   if(from != null) try {from.close();} catch(IOException e){;}
   if(to != null) try { to.close(); } catch(IOException e ){ ; }
  
  }
 
 }
 private static void abort(String msg) throws IOException {
  throw new IOException("FileCopy: "+msg);
 }

}