前言
之前看到某公司的官网的文章的浏览量刷新一次网页就会增加一次,给人的感觉不太好,一个公司的官网给人如此直白的漏洞,我批量发起请求的时候发现页面打开都报错,100多人的公司的官网文章刷新一次你给我看这个,这公司以前来过我们学校宣传招人+在园子里搜招聘的时候发现居然以前招xamarin,挺好奇的,所以就关注过。好吧不说这些了,只是扯扯蛋而已,回归主题,我想说的是csdn的文章可以通过设置代理ip刷新文章的浏览量,所以首先要做的就是这篇文章的主题“使用c#验证代理ip有效性”。
当然代理IP来源肯定是免费,所以嘛效率一般,从一些免费的代理ip的网页抓取的代理IP并不一定都是有用的,所以需要我们对我们抓取的代理ip进行验证,代理ip的有效时间也是有限,从10几秒到1个小时不限,大多数时间非常短,所以比如说,我们1分钟需要100个代理ip,那就1分钟获取一次,每次获取100个(这里是理想状态下的,抓取的代理ip都是有效的),原则上来说抓取下来后应该立即马上被使用。
当然这篇文章比较基础,一直觉得爬虫比较有趣,其实我在爬虫方面也是个小白,只是做一个简单的记录,如果有什么错误的地方,希望能提出建议。针对下面几个问题,我们就可以完成如何验证代理IP有效性的检测了。
1.从哪些网页上可以抓取免费的代理IP?
http://www.xicidaili.com
http://www.ip3366.net
http://www.66ip.cn
百度一下“免费代理ip”挺多的。
2.代理IP稳定吗?有什么作用?
这种免费的代理ip时效性和有效性都不强,上面这三个免费的代理网站,时效性大概在十几秒到1个小时不等,一般需要自己处理验证后使用,提高命中率。可适用于隐藏网页IP(有些网站还不准使用代理ip,比如豆瓣,其实挺尴尬的,内容这么贵吗),一般常用于空间留言、刷网站流量、网赚任务、批量注册账号等,只要没有其他限制,需要频繁更换ip都可以使用。
3.ping通IP就是有效的吗?如何验证代理是否有效
好吧,这有点废话,进行端口测试才是最有效的,能ping通并不代表代理有效,不能平通也不一定代理不可用。可以使用HttpWebRequest,也可以使用Scoket,当然HttpWebRequest比Socket连接代理ip、port要慢。
4.一次提取多少代理合适?
代理ip时效性不强、并且有效性也不高,所以只能从一些代理ip的网站上批量定时去获取,有的代理在一分钟内使用是有限制的,所以说限制比较多。
5.http代理和https代理有什么区别?
需要访问https的网站就需要使用https代理了,比如百度,需要访问http的代理,可以使用http。这个并不是100%的。
检测代理ip有效性步骤如下:
1.使用HttpWebRequest、HttpWebResponse请求代理ip的网页,获取包含代理的网页内容
2.使用HtmlAgilityPack或者正则表达式对抓取的内容进行截取,保存到代理集合
3.拿到代理集合,多线程发起http请求,比如访问百度,是否成功,成功则存到Redis里面。
效果图如下:
使用HttpWebRequest发起请求
Request.cs如下,主要就是两个方法,一个方法是验证代理ip是否有效,设置HttpWebRequest的Proxy属性,请求百度,看到有些文章大多数会获取响应的内容,如果内容符合请求的网址则证明代理哟有效,实际上根据HttpStatusCode 200就可以判断是否验证有效。
【注意】建的是控制台程序,使用了异步,所以还是建.net core吧,c#语言的版本7.1。C#如何在控制台程序中使用异步
public class Request { /// <summary> /// 验证代理ip有效性 /// </summary> /// <param name="proxyIp">代理IP</param> /// <param name="proxyPort">代理IP 端口</param> /// <param name="timeout">详情超时</param> /// <param name="url">请求的地址</param> /// <param name="success">成功的回调</param> /// <param name="fail">失败的回调</param> /// <returns></returns> public static async System.Threading.Tasks.Task getAsync(string proxyIp,int proxyPort, int timeout,string url, Action success, Action<string> fail) { System.GC.Collect(); HttpWebRequest request = null; HttpWebResponse response = null; try { request = (HttpWebRequest)WebRequest.Create(url); //HttpWebRequest request = HttpWebRequest.CreateHttp(url); request.Timeout =timeout; request.KeepAlive = false; request.Proxy = new WebProxy(proxyIp,proxyPort); response = await request.GetResponseAsync() as HttpWebResponse; if (response.StatusCode == HttpStatusCode.OK) { success(); } else { fail(response.StatusCode+":"+response.StatusDescription); } } catch (Exception ex) { fail("请求异常"+ex.Message.ToString()); } finally { if (request != null) { request.Abort(); request = null; } if (response != null) { response.Close(); } } } /// <summary> /// 发起http请求 /// </summary> /// <param name="url"></param> /// <param name="success">成功的回调</param> /// <param name="fail">失败的回调</param> public static void get(string url,Action<string> success,Action<string> fail) { StreamReader reader = null; Stream stream = null; WebRequest request = null; HttpWebResponse response = null; try { request = WebRequest.Create(url); request.Timeout = 2000; response = (HttpWebResponse)request.GetResponse(); if (response.StatusCode == HttpStatusCode.OK) { stream = response.GetResponseStream(); reader = new StreamReader(stream); string result = reader.ReadToEnd(); success(result); } else { fail(response.StatusCode+":"+response.StatusDescription); } } catch (Exception ex) { fail(ex.ToString()); } finally { if (reader != null) reader.Close(); if (stream != null) stream.Close(); if(response!=null) response.Close(); if(request!=null) request.Abort(); } } }
抓取免费代理,并检查是否有效
ProxyIpHelper.cs 中主要有四个方法,检查ip是否可用CheckProxyIpAsync、抓取xicidaili.com的代理GetXicidailiProxy、抓取ip3366.net的代理GetIp3366Proxy、抓取66ip.cn的代理GetIp3366Proxy。如果想多抓取几个网站可以多写几个。
public class ProxyIpHelper { private static string address_xicidaili = "http://www.xicidaili.com/wn/{0}"; private static string address_66ip = "http://www.66ip.cn/nmtq.php?getnum=20&isp=0&anonymoustype=0&start=&ports=&export=&ipaddress=&area=1&proxytype=1&api=66ip"; private static string address_ip3366 = "http://www.ip3366.net/?stype=1&page={0}"; /// <summary> /// 检查代理IP是否可用 /// </summary> /// <param name="ipAddress">ip</param> /// <param name="success">成功的回调</param> /// <param name="fail">失败的回调</param> /// <returns></returns> public static async Task CheckProxyIpAsync(string ipAddress, Action success, Action<string> fail) { int index = ipAddress.IndexOf(":"); string proxyIp = ipAddress.Substring(0, index); int proxyPort = int.Parse(ipAddress.Substring(index + 1)); await Request.getAsync(proxyIp, proxyPort, 3000, "https://www.baidu.com/", () => { success(); }, (error) => { fail(error); }); } /// <summary> /// 从xicidaili.com网页上去获取代理IP,可以分页 /// </summary> /// <param name="page"></param> /// <returns></returns> public static List<string> GetXicidailiProxy(int page) { List<string> list = new List<string>(); for (int p = 1; p <= page; p++) { string url = string.Format(address_xicidaili, p); Request.get(url,(docText)=> { if (!string.IsNullOrWhiteSpace(docText)) { HtmlDocument doc = new HtmlDocument(); doc.LoadHtml(docText); var trNodes = doc.DocumentNode.SelectNodes("//table[@id='ip_list']")[0].SelectNodes("./tr"); if (trNodes != null && trNodes.Count > 0) { for (int i = 1; i < trNodes.Count; i++) { var tds = trNodes[i].SelectNodes("./td"); string ipAddress = tds[1].InnerText + ":" + int.Parse(tds[2].InnerText); ; list.Add(ipAddress); } } } },(error)=> { Console.WriteLine(error); }); } return list; } /// <summary> /// 从ip3366.net网页上去获取代理IP,可以分页 /// </summary> /// <param name="page"></param> /// <returns></returns> public static List<string> GetIp3366Proxy(int page) { List<string> list = new List<string>(); for (int p = 1; p <= page; p++) { string url = string.Format(address_ip3366, p); Request.get(url, (docText) => { if (!string.IsNullOrWhiteSpace(docText)) { HtmlDocument doc = new HtmlDocument(); doc.LoadHtml(docText); var trNodes1 = doc.DocumentNode.SelectNodes("//table")[0]; var trNodes2 = doc.DocumentNode.SelectNodes("//table")[0].SelectSingleNode("//tbody"); var trNodes = doc.DocumentNode.SelectNodes("//table")[0].SelectSingleNode("//tbody").SelectNodes("./tr"); if (trNodes != null && trNodes.Count > 0) { for (int i = 1; i < trNodes.Count; i++) { var tds = trNodes[i].SelectNodes("./td"); if (tds[3].InnerHtml == "HTTPS") { string ipAddress = tds[0].InnerText + ":" + int.Parse(tds[1].InnerText); ; list.Add(ipAddress); } } } } }, (error) => { Console.WriteLine(error); }); } return list; } /// <summary> /// 从66ip.cn中去获取,不需要分页 /// </summary> /// <returns></returns> public static List<string> Get66ipProxy() { List<string> list = new List<string>(); Request.get(address_66ip, (docText)=> { int count = 0; if (string.IsNullOrWhiteSpace(docText) == false) { string regex = "\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\:\\d{1,5}"; Match mstr = Regex.Match(docText, regex); while (mstr.Success && count < 20) { string tempIp = mstr.Groups[0].Value; list.Add(tempIp); mstr = mstr.NextMatch(); count++; } } }, (error)=> { Console.WriteLine(error); }); return list; } }
使用Timer定时抓取,并检查,成功则保存到redis
c#有三种定时器,这里定时器是使用System.Threading命名空间, 这个Timer会开启新的线程,抓取三个网页定义了三个Timer对象。每一次抓取都会保存上一次抓取的集合,检查前,会进行对比,取出新的集合也就是没有重复的那部分。有效性的ip比较低,这里没有做统计,如果代码再优化一下,可以做一下统计,看看程序的主入口吧,最终的实现如下:
class Program { static bool timer_ip3366_isCompleted = true; static bool timer_xicidaili_isCompleted = true; static bool timer_66ip_isCompleted = true; static Timer timer_ip3366, timer_xicidaili, timer_66ip; private static List<string> lastListip3366,lastList66ip,lastListxicidaili;//保存上一次抓取的代理,与下一次进行对比,取新的集合进行检查筛选 static async Task Main(string[] args) { System.Net.ServicePointManager.DefaultConnectionLimit = 2000; Console.WriteLine("hellow proxyIp"); Console.ReadLine(); lastList66ip = new List<string>(); lastListip3366 = new List<string>(); lastListxicidaili = new List<string>(); timer_ip3366 = new Timer(async (state) => { await TimerIp3366Async(); }, "processing timer_ip3366 event", 0,1000*30); timer_xicidaili = new Timer(async (state) => { await TimerXicidailiAsync(); }, "processing timer_xicidaili event", 0, 1000 * 60); timer_66ip = new Timer(async (state) => { await Timer66ipAsync(); }, "processing timer_66ip event", 0, 1000*30); Console.ReadLine(); } private static async Task Timer66ipAsync() { if (timer_66ip_isCompleted) { timer_66ip_isCompleted = false; List<string> checkList = new List<string>(); var listProxyIp = ProxyIpHelper.Get66ipProxy(); if (listProxyIp.Count > 0) { Console.ForegroundColor = ConsoleColor.DarkCyan; Console.WriteLine("66ip.cn 抓取到" + listProxyIp.Count + "条记录,正在对比........."); listProxyIp.ForEach(f => { if (!lastList66ip.Contains(f)) { checkList.Add(f); } }); lastList66ip = listProxyIp; if (checkList.Count > 0) { Console.ForegroundColor = ConsoleColor.DarkCyan; Console.WriteLine("66ip.cn 需要检查" + checkList.Count + "条记录,正在进行检测是否有效.........."); for (int i = 0; i < checkList.Count; i++) { string ipAddress = checkList[i]; await ProxyIpHelper.CheckProxyIpAsync(ipAddress, () => { bool insertSuccess = RedisHelper.InsertSet(ipAddress); Console.ForegroundColor = ConsoleColor.White; Console.WriteLine("66ip.cn"); if (insertSuccess) { Console.WriteLine("success" + ipAddress + "任务编号:" + i + "当前任务线程:" + Thread.CurrentThread.ManagedThreadId); } Console.WriteLine("重复插入" + ipAddress + "任务编号:" + i + "当前任务线程:" + Thread.CurrentThread.ManagedThreadId); }, (error) => { Console.ForegroundColor = ConsoleColor.Green; Console.WriteLine("66ip.cn"); Console.WriteLine("error:" + ipAddress + error + "任务编号:" + i + "当前任务线程:" + Thread.CurrentThread.ManagedThreadId); }); } timer_66ip_isCompleted = true; Console.ForegroundColor = ConsoleColor.DarkCyan; Console.WriteLine("66ip.cn" + checkList.Count + "条记录,已经检测完成,正在进行下一次检查"); } else { timer_66ip_isCompleted = true; Console.ForegroundColor = ConsoleColor.DarkCyan; Console.WriteLine("66ip.cn没有需要检查的代理ip"); } } else { timer_66ip_isCompleted = true; Console.ForegroundColor = ConsoleColor.DarkCyan; Console.WriteLine("66ip.cn没有获取到代理ip"); } } } private static async Task TimerXicidailiAsync() { if (timer_xicidaili_isCompleted) { //取出需要检查的ip地址,第一次100条则checklist就是100条记录, //第二次的100条中只有10是和上一次的不重复,则第二次只需要检查这10条记录 timer_xicidaili_isCompleted = false; List<string> checkList = new List<string>(); var listProxyIp = ProxyIpHelper.GetXicidailiProxy(1); if (listProxyIp.Count > 0) { Console.WriteLine("xicidaili.com 抓取到" + listProxyIp.Count + "条记录,正在对比............"); listProxyIp.ForEach(f => { if (!lastListxicidaili.Contains(f)) { checkList.Add(f); } }); lastListxicidaili = listProxyIp; if (checkList.Count > 0) { Console.ForegroundColor = ConsoleColor.DarkCyan; Console.WriteLine("xicidaili.com 需要检查" + checkList.Count + "条记录,正在进行检测是否有效.........."); for (int i = 0; i < checkList.Count; i++) { string ipAddress = checkList[i]; await ProxyIpHelper.CheckProxyIpAsync(ipAddress, () => { bool insertSuccess = RedisHelper.InsertSet(ipAddress); Console.ForegroundColor = ConsoleColor.White; Console.WriteLine("xicidaili.com"); if (insertSuccess) { Console.WriteLine("success" + ipAddress + "任务编号:" + i + "当前任务线程:" + Thread.CurrentThread.ManagedThreadId); } else Console.WriteLine("重复插入" + ipAddress + "任务编号:" + i + "当前任务线程:" + Thread.CurrentThread.ManagedThreadId); }, (error) => { Console.WriteLine("xicidaili.com"); Console.ForegroundColor = ConsoleColor.Red; Console.WriteLine("error:" + ipAddress + error + "任务编号:" + i + "当前任务线程:" + Thread.CurrentThread.ManagedThreadId); }); } timer_xicidaili_isCompleted = true; Console.ForegroundColor = ConsoleColor.DarkCyan; Console.WriteLine("xicidaili.com" + checkList.Count + "条记录,已经检测完成,正在进行下一次检查"); } else { timer_xicidaili_isCompleted = true; Console.ForegroundColor = ConsoleColor.DarkCyan; Console.WriteLine("xicidaili.com没有需要检查的代理ip"); } } else { timer_xicidaili_isCompleted = true; Console.ForegroundColor = ConsoleColor.DarkCyan; Console.WriteLine("xicidaili.com没有获取到代理ip"); } } } private static async Task TimerIp3366Async() { if (timer_ip3366_isCompleted) { timer_ip3366_isCompleted = false; List<string> checkList = new List<string>(); var listProxyIp = ProxyIpHelper.GetIp3366Proxy(4); if (listProxyIp.Count > 0) { Console.ForegroundColor = ConsoleColor.DarkCyan; Console.WriteLine("ip3366.net 抓取到" + listProxyIp.Count + "条记录,正在进行检测是否有效.........."); listProxyIp.ForEach(f => { if (!lastListip3366.Contains(f)) { checkList.Add(f); } }); lastListip3366 = listProxyIp; if (checkList.Count != 0) { Console.ForegroundColor = ConsoleColor.DarkCyan; Console.WriteLine("ip3366.net 需要检查" + checkList.Count + "条记录,正在进行检测是否有效.........."); for (int i = 0; i < checkList.Count; i++) { string ipAddress = checkList[i]; await ProxyIpHelper.CheckProxyIpAsync(ipAddress, () => { bool insertSuccess = RedisHelper.InsertSet(ipAddress); Console.ForegroundColor = ConsoleColor.White; Console.WriteLine("ip3366.net"); if (insertSuccess) { Console.WriteLine("success" + ipAddress + "任务编号:" + i + "当前任务线程:" + Thread.CurrentThread.ManagedThreadId); } else { Console.ForegroundColor = ConsoleColor.Red; Console.WriteLine("重复插入" + ipAddress + "任务编号:" + i + "当前任务线程:" + Thread.CurrentThread.ManagedThreadId); } }, (error) => { Console.ForegroundColor = ConsoleColor.Yellow; Console.WriteLine("ip3366.net"); Console.WriteLine("error " + ipAddress + "任务编号:" + i + "当前任务线程:" + Thread.CurrentThread.ManagedThreadId); }); } timer_ip3366_isCompleted = true; Console.WriteLine("ip3366.net" + checkList.Count + "条记录,已经检测完成,正在进行下一次检查"); } else { timer_ip3366_isCompleted = true; Console.ForegroundColor = ConsoleColor.DarkCyan; Console.WriteLine("ip3366.net没有需要检查的代理ip"); } } else { timer_ip3366_isCompleted = true; Console.ForegroundColor = ConsoleColor.DarkCyan; Console.WriteLine("ip3366.net没有获取到代理ip"); } } } }
Redis第三库使用的stackoverflow的 StackExchange.Redis,代理ip不能重复储存,所以采用的数据结构是Set。存的值非常简单就一个ip加上port,也可以存入更多相关信息,感觉没必要。即使有这些其他的信息,也很难发挥作用。RedisHelper.cs如下
public class RedisHelper { private static readonly object Locker = new object(); private static ConnectionMultiplexer _redis; private const string CONNECTTIONSTRING = "127.0.0.1:6379,DefaultDatabase=3"; public const string REDIS_SET_KET_SUCCESS = "set_success_ip"; private static ConnectionMultiplexer Manager { get { if (_redis == null) { lock (Locker) { if (_redis != null) return _redis; _redis = GetManager(); return _redis; } } return _redis; } } private static ConnectionMultiplexer GetManager(string connectionString = null) { if (string.IsNullOrEmpty(connectionString)) { connectionString = CONNECTTIONSTRING; } return ConnectionMultiplexer.Connect(connectionString); } public static bool InsertSet(string value) { var db = Manager.GetDatabase(); return db.SetAdd(REDIS_SET_KET_SUCCESS,value); } }
总结
明天补上刷新网页浏览量的文章吧,代码还不够好,ip的有效性还不高,对多线程的使用还不是很熟练
好了,以上就是这篇文章的全部内容了,希望本文的内容对大家的学习或者工作具有一定的参考学习价值,如果有疑问大家可以留言交流,谢谢大家对易盾网络的支持。