import java.io.*;
import java.net.*;

public class Downloader {

    // small HTTP (web) client similar to wget program
    private static void download(String url) throws Exception {

        URL myURL = new URL(url);  // getFile() ==> filename

        URLConnection myConn = myURL.openConnection();

        // 1KB = 1024 Bytes (1 Byte = 8 bits)
        double totalSize = myConn.getContentLength();

        // network reader
        InputStream netIn = myURL.openStream();

        String fname = myURL.getFile();
        System.out.println("downloading " + fname + " " + totalSize + " bytes");

        FileOutputStream fileOut = new FileOutputStream("tmpFile.gif");

        byte[] buffer = new byte[512];
        double currentSize = 0; 

        int nByte = netIn.read(buffer); // fill buffer from current cursor position
        while (nByte != -1) {
            // write buffer to file
            fileOut.write(buffer);

            currentSize += nByte;

            nByte = netIn.read(buffer); // fill buffer from current cursor position
        }

        System.out.println("completed downloading: " + currentSize + " bytes");

        fileOut.close();
        netIn.close();

    }

    public static void main(String[] args) throws Exception {
        String url = "http://www.cs.gettysburg.edu/~skim/cs112/hws/hw3/Cat.gif";

        download(url);

        //new Downloader().download(url);  // if download is not static

    }

}