webDriver采集加速

                profile = new FirefoxProfile();
		profile.setPreference("javascript.enabled", true);
		profile.setPreference("permissions.default.stylesheet", 2);
		profile.setPreference("permissions.default.image", 2);

		profile.setPreference("browser.cache.disk.enable", false);
		profile.setPreference("browser.cache.memory.enable", false);
		profile.setPreference("browser.cache.offline.enable", false);
		profile.setPreference("network.http.use-cache", false);

经测试对于最新版本FIREFOX,profile.setPreference("permissions.default.image", 2);不可用,

https://groups.google.com/forum/#!msg/selenium-users/R6e-TKQjhEI/8x-qb-0RUIEJ

http://stackoverflow.com/questions/31571726/cant-turn-off-images-in-selenium-firefox

可以启动前手动进入firefox,about:config关闭图片加载..