/*This file is part of Socks via HTTP.This package is free software; you can redistribute it and/or modifyit under the terms of the GNU General Public License as published bythe Free Software Foundation; either version 2 of the License, or(at your option) any later version.Socks via HTTP is distributed in the hope that it will be useful,but WITHOUT ANY WARRANTY; without even the implied warranty ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See theGNU General Public License for more details.You should have received a copy of the GNU General Public Licensealong with Socks via HTTP; if not, write to the Free SoftwareFoundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA*/// Title :        HttpMessage.java// Version :      0.40// Copyright :    Copyright (c) 2001// Author :       Florent CUETO (fcueto@wanadoo.fr)// Description :  Http Message Datapackage socks4;import java.io.*;import java.net.*;import java.util.*;/** * A class to simplify HTTP applet-server communication.  It abstracts * the communication into messages, which can be either GET or POST. * <p> * It can be used like this: * <blockquote><pre> * URL url = new URL(getCodeBase(), "/servlet/ServletName"); * &nbsp; * HttpMessage msg = new HttpMessage(url); * &nbsp; * // Parameters may optionally be set using java.util.Properties * Properties props = new Properties(); * props.put("name", "value"); * &nbsp; * // Headers, cookies, and authorization may be set as well * msg.setHeader("Accept", "image/png");             // optional * msg.setCookie("JSESSIONID", "9585155923883872");  // optional * msg.setAuthorization("guest", "try2gueSS");       // optional * &nbsp; * InputStream in = msg.sendGetMessage(props); * </pre></blockquote> * <p> */public class HttpMessage {  URL servlet = null;  Hashtable headers = null;  /**   * Constructs a new HttpMessage that can be used to communicate with the   * servlet at the specified URL.   *   * @param servlet the server resource (typically a servlet) with which   * to communicate   */  public HttpMessage(URL servlet) {    this.servlet = servlet;  }  /**   * Performs a GET request to the servlet, with no query string.   *   * @return an InputStream to read the response   * @exception IOException if an I/O error occurs   */  public InputStream sendGetMessage() throws IOException {    return sendGetMessage(null);  }  /**   * Performs a GET request to the servlet, building   * a query string from the supplied properties list.   *   * @param args the properties list from which to build a query string   * @return an InputStream to read the response   * @exception IOException if an I/O error occurs   */  public InputStream sendGetMessage(Properties args) throws IOException {    String argString = "";  // default    if (args != null) {      argString = "?" + toEncodedString(args);    }    URL url = new URL(servlet.toExternalForm() + argString);    // Turn off caching    URLConnection con = url.openConnection();    con.setUseCaches(false);    // Send headers    sendHeaders(con);    return con.getInputStream();  }  /**   * Performs a POST request to the servlet, with no query string.   *   * @return an InputStream to read the response   * @exception IOException if an I/O error occurs   */  public InputStream sendPostMessage() throws IOException {    return sendPostMessage(null);  }  /**   * Performs a POST request to the servlet, building   * post data from the supplied properties list.   *   * @param args the properties list from which to build the post data   * @return an InputStream to read the response   * @exception IOException if an I/O error occurs   */  public InputStream sendPostMessage(Properties args) throws IOException {    String argString = "";  // default    if (args != null) {      argString = toEncodedString(args);  // notice no "?"    }    URLConnection con = servlet.openConnection();    // Prepare for both input and output    con.setDoInput(true);    con.setDoOutput(true);    // Turn off caching    con.setUseCaches(false);    // Work around a Netscape bug    con.setRequestProperty("Content-Type",                           "application/x-www-form-urlencoded");    // Send headers    sendHeaders(con);    // Write the arguments as post data    DataOutputStream out = new DataOutputStream(con.getOutputStream());    out.writeBytes(argString);    out.flush();    out.close();    return con.getInputStream();  }  /**   * Performs a POST request to the servlet, uploading a serialized object.   * <p>   * The servlet can receive the object in its <tt>doPost()</tt> method   * like this:   * <pre>   *     ObjectInputStream objin =   *       new ObjectInputStream(req.getInputStream());   *     Object obj = objin.readObject();   * </pre>   * The type of the uploaded object can be determined through introspection.   *   * @param obj the serializable object to upload   * @return an InputStream to read the response   * @exception IOException if an I/O error occurs   */  public InputStream sendPostMessage(Serializable obj) throws IOException {    URLConnection con = servlet.openConnection();    // Prepare for both input and output    con.setDoInput(true);    con.setDoOutput(true);    // Turn off caching    con.setUseCaches(false);    // Set the content type to be application/x-java-serialized-object    con.setRequestProperty("Content-Type",                           "application/x-java-serialized-object");    // Send headers    sendHeaders(con);    // Write the serialized object as post data    ObjectOutputStream out = new ObjectOutputStream(con.getOutputStream());    out.writeObject(obj);    out.flush();    out.close();    return con.getInputStream();  }  public InputStream sendGZippedPostMessage(Serializable obj) throws IOException {    URLConnection con = servlet.openConnection();    // Prepare for both input and output    con.setDoInput(true);    con.setDoOutput(true);    // Turn off caching    con.setUseCaches(false);    // Set the content type to be application/x-java-serialized-object    con.setRequestProperty("Content-Type", "application/x-java-serialized-object");    // Send headers    sendHeaders(con);    // Write the serialized object as post data    java.util.zip.GZIPOutputStream zos = new java.util.zip.GZIPOutputStream(con.getOutputStream());    ObjectOutputStream out = new ObjectOutputStream(zos);    out.writeObject(obj);    out.flush();    out.close();    return con.getInputStream();  }  /**   * Sets a request header with the given name and value.  The header   * persists across multiple requests.  The caller is responsible for   * ensuring there are no illegal characters in the name and value.   *   * @param name the header name   * @param value the header value   */  public void setHeader(String name, String value) {    if (headers == null) {      headers = new Hashtable();    }    headers.put(name, value);  }  // Send the contents of the headers hashtable to the server  private void sendHeaders(URLConnection con) {    if (headers != null) {      Enumeration enum = headers.keys();      while (enum.hasMoreElements()) {        String name = (String) enum.nextElement();        String value = (String) headers.get(name);        con.setRequestProperty(name, value);      }    }  }  /**   * Sets a request cookie with the given name and value.  The cookie   * persists across multiple requests.  The caller is responsible for   * ensuring there are no illegal characters in the name and value.   *   * @param name the header name   * @param value the header value   */  public void setCookie(String name, String value) {    if (headers == null) {      headers = new Hashtable();    }    String existingCookies = (String) headers.get("Cookie");    if (existingCookies == null) {      setHeader("Cookie", name + "=" + value);    }    else {      setHeader("Cookie", existingCookies + "; " + name + "=" + value);    }  }  /**   * Sets the authorization information for the request (using BASIC   * authentication via the HTTP Authorization header).  The authorization   * persists across multiple requests.   *   * @param name the user name   * @param name the user password   */  public void setAuthorization(String name, String password) {    String authorization = Base64Encoder.encode(name + ":" + password);    setHeader("Authorization", "Basic " + authorization);  }  public void setProxyAuthorization(String name, String password) {    String authorization = Base64Encoder.encode(name + ":" + password);    setHeader("Proxy-Authorization", "Basic " + authorization);  }  /*   * Converts a properties list to a URL-encoded query string   */  private String toEncodedString(Properties args) {    StringBuffer buf = new StringBuffer();    Enumeration names = args.propertyNames();    while (names.hasMoreElements()) {      String name = (String) names.nextElement();      String value = args.getProperty(name);      buf.append(URLEncoder.encode(name) + "=" + URLEncoder.encode(value));      if (names.hasMoreElements()) buf.append("&");    }    return buf.toString();  }}