Le protocole HTTP: Client HTTP Java

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

public class HttpClient
{
  protected URL url;
  protected HttpURLConnection server;

  /**
   * @param szUrl: String object for the URL
   */
  public HttpClient(String szUrl) throws Exception
  {
    try
    {
      url = new URL(szUrl);
    }
    catch (Exception e)
    {
      throw new Exception("Invalid URL");
    }
  }

  /**
   * @param method: String object for client method (POST, GET,...)
   */
  public void connect(String method) throws Exception
  {
    try
    {
      server = (HttpURLConnection)url.openConnection();
      server.setDoInput(true);
      server.setDoOutput(true);
      server.setRequestMethod(method);
      server.setRequestProperty("Content-type",
                                "application/x-www-form-urlencoded");
      server.connect();
    }
    catch (Exception e)
    {
      throw new Exception("Connection failed");
    }
  }

  public void disconnect()
  {
    server.disconnect();
  }

  public void displayResponse() throws Exception
  {
    String line;

    try
    {
      BufferedReader s = new BufferedReader(
                            new InputStreamReader(
                                server.getInputStream()));
      line = s.readLine();
      while (line != null)
      {
        System.out.println(line);
        line = s.readLine();
      }
      s.close();
    }
    catch(Exception e)
    {
      throw new Exception("Unable to read input stream");
    }
  }

  public void post(String s) throws Exception
  {
    try
    {
      BufferedWriter bw = new BufferedWriter(
                                new OutputStreamWriter(
                                    server.getOutputStream()));
      bw.write(s, 0, s.length());
      bw.flush();
      bw.close();
    }
    catch(Exception e)
    {
      throw new Exception("Unable to write to output stream");
    }
  }

  public static void main(String argv[])
  {
    if (argv.length == 0)
    {
        System.out.println("Usage: java HttpClient url\r\n");
        System.exit(0);
    }

    try
    {
      HttpClient c = new HttpClient(argv[0]);
      c.connect("GET");
      c.displayResponse();
      c.disconnect();

      c.connect("POST");
      c.post("data=Posted request");
      c.displayResponse();
      c.disconnect();

      c.connect("POST");
      c.post("data=2nd request");
      c.displayResponse();
      c.disconnect();
    }
    catch (Exception e)
    {
      e.printStackTrace();
    }
  }
}