高級網頁抓取功能

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HttpIdentity 功能

一些網站系統要求使用者登入後才能查看內容；在這種情況下，我們可以使用 HttpIdentity： -

HttpIdentity id = new HttpIdentity();
id.NetworkUsername = "username";
id.NetworkPassword = "pwd";
Identities.Add(id);

HttpIdentity id = new HttpIdentity();
id.NetworkUsername = "username";
id.NetworkPassword = "pwd";
Identities.Add(id);

Dim id As New HttpIdentity()
id.NetworkUsername = "username"
id.NetworkPassword = "pwd"
Identities.Add(id)

VB C#

在 IronWebScraper 中最令人印象深刻和强大的功能之一，是能够使用数千种独特的(用戶的憑證和/或瀏覽器引擎)利用多重登入會話來欺騙或抓取網站。

public override void Init()
{
    License.LicenseKey = " LicenseKey ";
    this.LoggingLevel = WebScraper.LogLevel.All;
    this.WorkingDirectory = AppSetting.GetAppRoot() + @"\ShoppingSiteSample\Output\";
    var proxies = "IP-Proxy1: 8080,IP-Proxy2: 8081".Split(',');
    foreach (var UA in IronWebScraper.CommonUserAgents.ChromeDesktopUserAgents)
    {
        foreach (var proxy in proxies)
        {
            Identities.Add(new HttpIdentity()
            {
                UserAgent = UA,
                UseCookies = true,
                Proxy = proxy
            });
        }
    }
    this.Request("http://www.Website.com", Parse);
}

public override void Init()
{
    License.LicenseKey = " LicenseKey ";
    this.LoggingLevel = WebScraper.LogLevel.All;
    this.WorkingDirectory = AppSetting.GetAppRoot() + @"\ShoppingSiteSample\Output\";
    var proxies = "IP-Proxy1: 8080,IP-Proxy2: 8081".Split(',');
    foreach (var UA in IronWebScraper.CommonUserAgents.ChromeDesktopUserAgents)
    {
        foreach (var proxy in proxies)
        {
            Identities.Add(new HttpIdentity()
            {
                UserAgent = UA,
                UseCookies = true,
                Proxy = proxy
            });
        }
    }
    this.Request("http://www.Website.com", Parse);
}

Public Overrides Sub Init()
	License.LicenseKey = " LicenseKey "
	Me.LoggingLevel = WebScraper.LogLevel.All
	Me.WorkingDirectory = AppSetting.GetAppRoot() & "\ShoppingSiteSample\Output\"
	Dim proxies = "IP-Proxy1: 8080,IP-Proxy2: 8081".Split(","c)
	For Each UA In IronWebScraper.CommonUserAgents.ChromeDesktopUserAgents
		For Each proxy In proxies
			Identities.Add(New HttpIdentity() With {
				.UserAgent = UA,
				.UseCookies = True,
				.Proxy = proxy
			})
		Next proxy
	Next UA
	Me.Request("http://www.Website.com", Parse)
End Sub

VB C#

您有多個屬性可以提供不同的行為，因此可以防止網站封鎖您。

以下是其中一些屬性： -

NetworkDomain：用於用戶認證的網路域。支持Windows、NTLM、Kerberos、Linux、BSD和Mac OS X網絡。必須與此同時使用(網絡用戶名和網絡密碼)
NetworkUsername：用於使用者身份驗證的網路/HTTP 使用者名稱。支持 Http、Windows 網路、NTLM、Kerberos、Linux 網路、BSD 網路和 Mac OS。
NetworkPassword：用於用戶認證的網絡/HTTP 密碼。支持Http、Windows網絡、NTLM、Keroberos、Linux網絡、BSD網絡和Mac OS。
代理：設定代理伺服器設置
UserAgent：設置瀏覽器引擎(Chrome 桌面版、Chrome Mobile、Chrome 平板版、IE 和 Firefox 等。)
HttpRequestHeaders：用於將與此身份一起使用的自定義標頭值，並接受字典物件。(字典<string,string>)
UseCookies：啟用/禁用使用 cookies
IronWebScraper 使用隨機身份運行抓取器。如果我們需要指定使用特定的身份來解析頁面，我們可以這樣做。

public override void Init()
{
    License.LicenseKey = " LicenseKey ";
    this.LoggingLevel = WebScraper.LogLevel.All;
    this.WorkingDirectory = AppSetting.GetAppRoot() + @"\ShoppingSiteSample\Output\";
    HttpIdentity identity = new HttpIdentity();
    identity.NetworkUsername = "username";
    identity.NetworkPassword = "pwd";
    Identities.Add(id);
    this.Request("http://www.Website.com", Parse, identity);
}

public override void Init()
{
    License.LicenseKey = " LicenseKey ";
    this.LoggingLevel = WebScraper.LogLevel.All;
    this.WorkingDirectory = AppSetting.GetAppRoot() + @"\ShoppingSiteSample\Output\";
    HttpIdentity identity = new HttpIdentity();
    identity.NetworkUsername = "username";
    identity.NetworkPassword = "pwd";
    Identities.Add(id);
    this.Request("http://www.Website.com", Parse, identity);
}

Public Overrides Sub Init()
	License.LicenseKey = " LicenseKey "
	Me.LoggingLevel = WebScraper.LogLevel.All
	Me.WorkingDirectory = AppSetting.GetAppRoot() & "\ShoppingSiteSample\Output\"
	Dim identity As New HttpIdentity()
	identity.NetworkUsername = "username"
	identity.NetworkPassword = "pwd"
	Identities.Add(id)
	Me.Request("http://www.Website.com", Parse, identity)
End Sub

VB C#

啟用網頁快取功能

此功能用於緩存請求的頁面。它經常在開發和測試階段使用；允許開發者在更新代碼後緩存所需的頁面以供重用。這使您能夠在重新啟動您的網絡抓取工具後，在已緩存的頁面上執行代碼，而無需每次都連接到實時網站。(即時回放).

您可以在 Init 中使用它。()方法

啟用網頁快取();`

或

啟用網頁快取(時限到期);`

它將您的快取資料儲存到工作目錄資料夾下的WebCache資料夾中。

public override void Init()
{
    License.LicenseKey = " LicenseKey ";
    this.LoggingLevel = WebScraper.LogLevel.All;
    this.WorkingDirectory = AppSetting.GetAppRoot() + @"\ShoppingSiteSample\Output\";
    EnableWebCache(new TimeSpan(1,30,30));
    this.Request("http://www.WebSite.com", Parse);
}

public override void Init()
{
    License.LicenseKey = " LicenseKey ";
    this.LoggingLevel = WebScraper.LogLevel.All;
    this.WorkingDirectory = AppSetting.GetAppRoot() + @"\ShoppingSiteSample\Output\";
    EnableWebCache(new TimeSpan(1,30,30));
    this.Request("http://www.WebSite.com", Parse);
}

Public Overrides Sub Init()
	License.LicenseKey = " LicenseKey "
	Me.LoggingLevel = WebScraper.LogLevel.All
	Me.WorkingDirectory = AppSetting.GetAppRoot() & "\ShoppingSiteSample\Output\"
	EnableWebCache(New TimeSpan(1,30,30))
	Me.Request("http://www.WebSite.com", Parse)
End Sub

VB C#

IronWebScraper 也具有在重新啟動代碼後通過使用 Start 設置引擎啟動過程名稱來使您的引擎繼續抓取的功能。(爬行ID)

static void Main(string [] args)
{
    // Create Object From Scraper class
    EngineScraper scrape = new EngineScraper();
    // Start Scraping
    scrape.Start("enginestate");
}

static void Main(string [] args)
{
    // Create Object From Scraper class
    EngineScraper scrape = new EngineScraper();
    // Start Scraping
    scrape.Start("enginestate");
}

Shared Sub Main(ByVal args() As String)
	' Create Object From Scraper class
	Dim scrape As New EngineScraper()
	' Start Scraping
	scrape.Start("enginestate")
End Sub

VB C#

執行請求和回應將被保存到工作目錄內的 SavedState 資料夾中。

限流

我們可以控制每個域的最小和最大連接數以及連接速度。

public override void Init()
{
    License.LicenseKey = "LicenseKey";
    this.LoggingLevel = WebScraper.LogLevel.All;
    this.WorkingDirectory = AppSetting.GetAppRoot() + @"\ShoppingSiteSample\Output\";
    // Gets or sets the total number of allowed open HTTP requests (threads)
    this.MaxHttpConnectionLimit = 80;
    // Gets or sets minimum polite delay (pause)between request to a given domain or IP address.
    this.RateLimitPerHost = TimeSpan.FromMilliseconds(50);            
    //     Gets or sets the allowed number of concurrent HTTP requests (threads) per hostname
    //     or IP address. This helps protect hosts against too many requests.
    this.OpenConnectionLimitPerHost = 25;
    this.ObeyRobotsDotTxt = false;
    //     Makes the WebSraper intelligently throttle requests not only by hostname, but
    //     also by host servers' IP addresses. This is polite in-case multiple scraped domains
    //     are hosted on the same machine.
    this.ThrottleMode = Throttle.ByDomainHostName;
    this.Request("https://www.Website.com", Parse);
}

public override void Init()
{
    License.LicenseKey = "LicenseKey";
    this.LoggingLevel = WebScraper.LogLevel.All;
    this.WorkingDirectory = AppSetting.GetAppRoot() + @"\ShoppingSiteSample\Output\";
    // Gets or sets the total number of allowed open HTTP requests (threads)
    this.MaxHttpConnectionLimit = 80;
    // Gets or sets minimum polite delay (pause)between request to a given domain or IP address.
    this.RateLimitPerHost = TimeSpan.FromMilliseconds(50);            
    //     Gets or sets the allowed number of concurrent HTTP requests (threads) per hostname
    //     or IP address. This helps protect hosts against too many requests.
    this.OpenConnectionLimitPerHost = 25;
    this.ObeyRobotsDotTxt = false;
    //     Makes the WebSraper intelligently throttle requests not only by hostname, but
    //     also by host servers' IP addresses. This is polite in-case multiple scraped domains
    //     are hosted on the same machine.
    this.ThrottleMode = Throttle.ByDomainHostName;
    this.Request("https://www.Website.com", Parse);
}

Public Overrides Sub Init()
	License.LicenseKey = "LicenseKey"
	Me.LoggingLevel = WebScraper.LogLevel.All
	Me.WorkingDirectory = AppSetting.GetAppRoot() & "\ShoppingSiteSample\Output\"
	' Gets or sets the total number of allowed open HTTP requests (threads)
	Me.MaxHttpConnectionLimit = 80
	' Gets or sets minimum polite delay (pause)between request to a given domain or IP address.
	Me.RateLimitPerHost = TimeSpan.FromMilliseconds(50)
	'     Gets or sets the allowed number of concurrent HTTP requests (threads) per hostname
	'     or IP address. This helps protect hosts against too many requests.
	Me.OpenConnectionLimitPerHost = 25
	Me.ObeyRobotsDotTxt = False
	'     Makes the WebSraper intelligently throttle requests not only by hostname, but
	'     also by host servers' IP addresses. This is polite in-case multiple scraped domains
	'     are hosted on the same machine.
	Me.ThrottleMode = Throttle.ByDomainHostName
	Me.Request("https://www.Website.com", Parse)
End Sub

VB C#

節流屬性

MaxHttpConnectionLimit

允許打開的 HTTP 請求總數 (線程)
RateLimitPerHost

最小禮貌延遲或暫停 (以毫秒計算)在請求到指定域名或IP地址之間
OpenConnectionLimitPerHost

允許的同時 HTTP 請求數量 (線程)
限速模式

使WebScraper不僅根據主機名稱，而且根據主機伺服器的IP地址智能地限制請求。這是出於禮貌，以防多個抓取的網域託管在同一台機器上。
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