Working with URLs

Reading Directly from a URL

After you've successfully created a URL, you can call the URL's openStream() method to get a stream from which you can read the contents of the URL. The openStream() method returns a java.io.InputStreamobject, so reading from a URL is as easy as reading from an input stream.

The following small Java program uses openStream() to get an input stream on the URL http://www.yahoo.com/. It then opens a BufferedReader on the input stream and reads from the BufferedReader thereby reading from the URL. Everything read is copied to the standard output stream:

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

public class URLReader {
    public static void main(String[] args) throws Exception {
	URL yahoo = new URL("http://www.yahoo.com/");
	BufferedReader in = new BufferedReader(
				new InputStreamReader(
				yahoo.openStream()));

	String inputLine;

	while ((inputLine = in.readLine()) != null)
	    System.out.println(inputLine);

	in.close();
    }
}

When you run the program, you should see, scrolling by in your command window, the HTML commands and textual content from the HTML file located at http://www.yahoo.com/. Alternatively, the program might hang or you might see an exception stack trace. If either of the latter two events occurs, you may have to set the proxy host so that the program can find the Yahoo server.

Working with URLs