static public void main(String[] argv) throws Exception
    {
//	if (argv.length != 2) {
//	    System.err.println("usage: java HTMLLinkExtractor [url] [file-to-process]");
//	    System.exit(1);
//	}

	// argv[0] should be in the form of proto://host.domain/dir/file
	URL aUrl = new URL("http://index.html");
	File aFile = new File("D:/2013-spring/index.html");
	InputStream in = new FileInputStream(aFile);
	String page = "";
	int c = in.read();

	while (c >= 0)
	    {
		page += (char)c;
		c = in.read();
	    }
	HTMLLinkExtractor htmlExtractor = 
	    new HTMLLinkExtractor(page, aUrl);

	System.out.println("count of urls : " + htmlExtractor.urls.size());
	htmlExtractor.printAllUrls();
    }