import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class URLReader {

	/**
	 * This method sends a GET request for the item at a specified URL, the prints the 
	 * response. Note that the approach used to read the response assumes that the item
	 * is text and not binary data like a .jpg. If there's a command-line argument to
	 * the program it's used as the URL, otherwise we fetch the author's page from the
	 * first Wireshark lab.
	 * 
	 * @author brichards
	 */
	public static void main(String[] args) throws Exception {
		String urlString = "http://gaia.cs.umass.edu/wireshark-labs/INTRO-wireshark-file1.html";
		if (args.length > 0) {
			urlString = args[0];
		}

		// Now we need to build an official URL object, create an HttpURLConnection object
		// to represent the connection to the appropriate server, and open the connection.
		URL url = new URL(urlString);
		HttpURLConnection urlCon = (HttpURLConnection) url.openConnection();
		urlCon.connect();

		// Opening the connection automatically constructed and sent a GET request. Now we
		// just need to read the response. First we ask the connection object for the 
		// stream that will contain the incoming data, then we read data from the stream
		// until the data runs out. No need to deal with the HTTP header on the incoming
		// data -- HttpURLConnection is smart enough to strip that out for us.
		InputStream inputStream = urlCon.getInputStream();
		BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));

		String line = reader.readLine(); // reads a line
		while(line != null) {
			System.out.println(line);
			line = reader.readLine();
		}
	}
}