package networking;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;

import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLEncoder;

/**
 *   Application to write to a URL, using a URLConnection class.
 *   (Note that this is NOT a Writer, like PrintWriter.)
 */
public class URLConnectionWriter
{
  /**
   * Main entry point
   *   @param args the command line arguments
   *               args[0] contains the URL to write to
   */
  public static void main(String[] args)
  {
    if (args.length < 1)
    {
      System.err.println(
          "Usage: java networking.Reverse <string-to-reverse>");
    }
    else
    {
      try
      {
        doWork(args[0]);
      } 
      catch (MalformedURLException ex)
      {
        ex.printStackTrace();
      } 
      catch (IOException ex)
      {
        ex.printStackTrace();
      }
    }
  }
    
  /**
   * Do the actual work
   * @param urlString the URL to connect to
   */
  private static void doWork(String urlString)
    throws MalformedURLException, IOException
  {
    // Translate into x-www-form-urlencoded format:
    String reverseMe = URLEncoder.encode(urlString, "UTF-8");
    
    // Open connection to URL
    URL url = new URL("http://java.sun.com/cgi-bin/backwards");
    URLConnection conn = url.openConnection();
    // Set connection so it can do output
    conn.setDoOutput(true);
    
    // Provide input to server using the output stream.
    PrintWriter out = new PrintWriter(conn.getOutputStream());
    try
    {
      out.println("string=" + reverseMe);
    }
    finally
    {
      out.close();
    }
    
    // Read response from server
    BufferedReader in = new BufferedReader(
                              new InputStreamReader(
                                    conn.getInputStream()));
    String line = null;
    try
    {
      while (true)
      {
        line = in.readLine();
        if (line == null)
          break;
        System.out.println(line);
      }
    }
    finally
    {
      in.close();
    }
  }
}