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

public class urlconnection
{
    public static void main(String[] args)
    {
        StringBuffer document = new StringBuffer();
        try 
        {
            URL url = new URL("http://www.163.com");
            URLConnection conn = url.openConnection();
            BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
            String line = null;
            while ((line = reader.readLine()) != null)
            document.append(line + " ");
            reader.close();
        }
        catch (MalformedURLException e) 
        {
            e.printStackTrace(); 
        }
        catch (IOException e)
        {
            e.printStackTrace(); 
        }
        System.out.println(document.toString());
    }
}
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方法二：
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import java.net.*;
import java.io.*;

public class useSourceViewer
{
    public static void main (String[] args) 
    {
        if (args.length > 0) 
        {
            try 
            {

                URL u = new URL(args[0]);
                InputStream in = u.openStream( );

                in = new BufferedInputStream(in);

                Reader r = new InputStreamReader(in);
                int c;
                while ((c = r.read( )) != -1) 
                {
                    System.out.print((char) c);
                }
                Object o = u.getContent( );
                System.out.println("I got a " + o.getClass().getName( ));
            }
            catch (MalformedURLException e) 
            {
                System.err.println(args[0] + " is not a parseable URL");
            }
            catch (IOException e) 
            {
                System.err.println(e);
            }
        } 
    }
}