With Java, you can easily write a client program that connects to a Web server and downloads an HTML file. You can also easily expand this simple program into a Web crawler by parsing the downloaded file, extracting the links referenced in that file, and using similar code to download the referenced files from the servers identified by those links. But be careful–you might download the whole Web onto your computer!
This program displays a specified HTML file on a specified server in raw text format:
import java.net.*;import java.io.*;class SocketHttp01{ public static void main(String[] args){ String server = "www.phrantic.com";//server name int port = 80; //http port try{ Socket socket = new Socket(server,port);//get socket //Get input and output streams from the socket BufferedReader inputStream = new BufferedReader(new InputStreamReader( socket.getInputStream())); PrintWriter outputStream = new PrintWriter(new OutputStreamWriter( socket.getOutputStream()),true); outputStream.println("GET /scoop/2train.htm"); //GET a specified file String line = null; while((line = inputStream.readLine()) != null) System.out.println(line); //Loop reading and displaying lines. socket.close(); }//end try catch(UnknownHostException e){ System.out.println(e); System.out.println( "Connection Failure. Are you online?"); }//end catch UnknownHostException catch(IOException e){System.out.println(e);} }//end main}//end class SocketHttp01