HTTPのレスポンスを取得 その２

function hello(){

  var uri = Components.classes["@mozilla.org/network/standard-url;1"]

    .createInstance(Components.interfaces.nsIURI);

  uri.spec = "http://www.google.com/";
  var ios = Components.classes["@mozilla.org/network/io-service;1"]

    .getService( Components.interfaces.nsIIOService );

  var channel = ios.newChannelFromURI(uri);
  var input = Components.classes["@mozilla.org/scriptableinputstream;1"]

    .createInstance(Components.interfaces.nsIScriptableInputStream);
  input.init(channel.open());

  alert(input.read(5000));

}