本文连接:
受业务影响，决定将Downloader单独分层，做出修改。
最近在做爬虫，之前一直在使用 HttpWebRequest 和 WebClient ,很方便快捷，也很适合新手，但随着抓取任务的增多，多任务，多库等情况的出现，使用一个优秀的爬虫框架是十分必要的。于是开始接触dotnetspider。
借鉴一下框架的设计图，在引入dotnetspider的NuGet包后，我基本也是按照这个进行了分层
Data.Spider - 存放前台页面(Winform、控制台)和实体爬虫(EntitySpider)等，相当于发起请求的起点。
Spider.Downloader - 封装请求等信息，可实现自定义cookie等，非必须。
Spider.Processor - 处理器，继承 IPageProcessor 实现对抓取内容的处理
Spider.Pipe - 管道，我将它理解为经过了 Processor 处理后的一个回调，将处理好的数据存储(文件、数据库等)
Spider.Entity - 数据实体类，继承 SpiderEntity
Spider.Command - 一些常用的公用命令，我这目前存放着转数据格式类，后台执行JS类，SqlHelper(因架构自带数据库管道，暂时没用)等
这样的分层也是参考了源码的示例
随着这几天的尝试，真的发现这个框架真的非常灵活，以凹凸租车的爬虫为例，上代码
实体类：
[EntityTable("CarWinsSpider", "AtzucheCar", EntityTable.Today)]
[EntitySelector(Expression = "$.data.content[*]", Type = SelectorType.JsonPath)]public class AtzucheModel : SpiderEntity
{
/// <summary>
/// 车辆编号/// </summary>[PropertyDefine(Expression = "$.carNo", Type = SelectorType.JsonPath)]public int carNo { get; set; }/// <summary>/// 品牌/// </summary>//[ReplaceFormatter(NewValue = "", OldValue = "\r")]//[ReplaceFormatter(NewValue = "", OldValue = "\t")]//[ReplaceFormatter(NewValue = "", OldValue = " ")]//[ReplaceFormatter(NewValue = "", OldValue = "\n")]//[ReplaceFormatter(NewValue = "", OldValue = "\"")]//[ReplaceFormatter(NewValue = "", OldValue = " ")][PropertyDefine(Expression = "$.brand", Type = SelectorType.JsonPath)]public string brand { get; set; }/// <summary>/// 地址/// </summary>[PropertyDefine(Expression = "$.carAddr", Type = SelectorType.JsonPath)]public string carAddr { get; set; }/// <summary>/// 车系/// </summary>[PropertyDefine(Expression = "$.type", Type = SelectorType.JsonPath)]public string type { get; set; }/// <summary>/// 排量/// </summary>[PropertyDefine(Expression = "$.sweptVolum", Type = SelectorType.JsonPath)]public string sweptVolum { get; set; }/// <summary>/// 图片/// </summary>[PropertyDefine(Expression = "$.coverPic", Type = SelectorType.JsonPath)]public string coverPic { get; set; }/// <summary>/// 日租金/// </summary>[PropertyDefine(Expression = "$.dayPrice", Type = SelectorType.JsonPath)]public int dayPrice { get; set; }/// <summary>/// 公里数/// </summary>[PropertyDefine(Expression = "$.distance", Type = SelectorType.JsonPath)]public string distance { get; set; }/// <summary>/// 评分/// </summary>[PropertyDefine(Expression = "$.evalScore", Type = SelectorType.JsonPath)]public string evalScore { get; set; }[PropertyDefine(Expression = "$.gbType", Type = SelectorType.JsonPath)]public string gbType { get; set; }/// <summary>/// 车牌/// </summary>[PropertyDefine(Expression = "$.plateNum", Type = SelectorType.JsonPath)]public string plateNum { get; set; }[PropertyDefine(Expression = "$.replyTag", Type = SelectorType.JsonPath)]public string replyTag { get; set; }[PropertyDefine(Expression = "$.transCount", Type = SelectorType.JsonPath)]public string transCount { get; set; }/// <summary>/// 年款/// </summary>[PropertyDefine(Expression = "$.year", Type = SelectorType.JsonPath)]public int year { get; set; }[PropertyDefine(Expression = "$.isPrivilege", Type = SelectorType.JsonPath)]public int isPrivilege { get; set; }[PropertyDefine(Expression = "$.isRecommend", Type = SelectorType.JsonPath)]public int isRecommend { get; set; }[PropertyDefine(Expression = "$.isUpgrade", Type = SelectorType.JsonPath)]public int isUpgrade { get; set; }[PropertyDefine(Expression = "$.lat", Type = SelectorType.JsonPath)]public string lat { get; set; }[PropertyDefine(Expression = "$.lon", Type = SelectorType.JsonPath)]public string lon { get; set; }[PropertyDefine(Expression = "$.queryId", Type = SelectorType.JsonPath)]public string queryId { get; set; }[PropertyDefine(Expression = "$.supplyCarService", Type = SelectorType.JsonPath)]public int supplyCarService { get; set; }[PropertyDefine(Expression = "$.freeCarService", Type = SelectorType.JsonPath)]public int freeCarService { get; set; }[PropertyDefine(Expression = "$.isShenMaCar", Type = SelectorType.JsonPath)]public int isShenMaCar { get; set; }[PropertyDefine(Expression = "$.supportGetReturn", Type = SelectorType.JsonPath)]public int supportGetReturn { get; set; }[PropertyDefine(Expression = "$.confirmation", Type = SelectorType.JsonPath)]public int confirmation { get; set; }}
起始：
/// <summary>
/// 应用程序的主入口点。 /// </summary> [STAThread]static void Main()
{
var site = new Site
{ CycleRetryTimes = 1, SleepTime = 200, Headers = new Dictionary<string, string>() { {"Accept","application/json, text/javascript, */*; q=0.01" }, {"Accept-Encoding","gzip, deflate" }, {"gzip, deflate","zh-CN,zh;q=0.9" }, {"X-Requested-With","XMLHttpRequest" }, { "Referer", "http://www.atzuche.com/hz/car/search"}, { "Connection","keep-alive" }, { "Content-Type","application/json;charset=UTF-8" }, { "Host","www.atzuche.com"}, { "User-Agent","Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36"} }};List<Request> resList = new List<Request>();Request res = new Request();
//res.PostBody = $"id=7&j=%7B%22createMan%22%3A%2218273159100%22%2C%22createTime%22%3A1518433690000%2C%22row%22%3A5%2C%22siteUserActivityListId%22%3A8553%2C%22siteUserPageRowModuleId%22%3A84959%2C%22topids%22%3A%22%22%2C%22wherePhase%22%3A%221%22%2C%22wherePreferential%22%3A%220%22%2C%22whereUsertype%22%3A%220%22%7D&page={i}&shopid=83106681";//据说是post请求需要res.Url = "http://www.atzuche.com/car/searchListMap/2?cityCode=330100&sceneCode=U002&filterCondition%5Blon%5D=120.219294&filterCondition%5Blat%5D=30.259258&filterCondition%5Bseq%5D=4&pageNum=1&pageSize=0";res.Method = System.Net.Http.HttpMethod.Get;resList.Add(res);
var spider = DotnetSpider.Core.Spider.Create(site, new QueueDuplicateRemovedScheduler(), new AtzucheProcessor())
.AddStartRequests(resList.ToArray())//页面抓取整理.AddPipeline(new AtzuchePipe());//数据回调//----------------------------------
spider.Monitor = new DotnetSpider.Core.Monitor.NLogMonitor();spider.Downloader = new AtzucheDownloader(); //new DotnetSpider.Core.Downloader.HttpClientDownloader();spider.ClearSchedulerAfterComplete = false;//爬虫结束后不取消调度器//----------------------------------spider.ThreadNum = 1;
spider.Run();Console.WriteLine("Press any key to continue...");
Console.Read();}
这里也可将整个抓取方法当做一个Spider实例单独放置 -> EntitySpider
/// <summary>
/// 应用程序的主入口点。 /// </summary> [STAThread]static void Main()
{
AtzucheEntitySpider dDengEntitySpider = new AtzucheEntitySpider();
dDengEntitySpider.AddPageProcessor(new AtzucheProcessor());//控制器 dDengEntitySpider.AddPipeline(new AtzuchePipe());//回调 dDengEntitySpider.ThreadNum = 1; dDengEntitySpider.Run(); Console.WriteLine("Press any key to continue..."); Console.Read();}
Downloader
对目标的请求全部包含着这里，可以根据需要自行设置，下篇将进行自定义Request的应用
public class AtzucheDownloader : BaseDownloader
{ protected override Page DowloadContent(Request request, ISpider spider) { return new HttpClientDownloader().Download(request, spider); }}新建爬虫实体类
public class AtzucheEntitySpider : EntitySpider
{ protected override void MyInit(params string[] arguments) { AddPipeline(new SqlServerEntityPipeline("Server=.;Database=AuzucheSpider;uid=sa;pwd=123;MultipleActiveResultSets=true"));//注意连接字符串中数据库不能带 . 亲测报错。。。 AddStartUrl("http://www.atzuche.com/car/searchListMap/2?cityCode=330100&sceneCode=U002&filterCondition%5Blon%5D=120.219294&filterCondition%5Blat%5D=30.259258&filterCondition%5Bseq%5D=4&pageNum=1&pageSize=0"); AddEntityType<AtzucheModel>();//如添加此实体类，框架将会根据此实体类上面的特性选择进行匹配，匹配成功后插入数据库，固可以省略Processor和Pipe，或者不使用此句，通过控制器和回调自定义存储方法 }public AtzucheEntitySpider() : base("AuzucheSpider", new Site
{ CycleRetryTimes = 1, SleepTime = 200, Headers = new Dictionary<string, string>() { {"Accept","application/json, text/javascript, */*; q=0.01" }, {"Accept-Encoding","gzip, deflate" }, {"gzip, deflate","zh-CN,zh;q=0.9" }, {"X-Requested-With","XMLHttpRequest" }, { "Referer", "http://www.atzuche.com/hz/car/search"}, { "Connection","keep-alive" }, { "Content-Type","application/json;charset=UTF-8" }, { "Host","www.atzuche.com"}, { "User-Agent","Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36"} }}){ }}
接下来是处理器：
解析抓取的数据封装到"AtzucheList"内，可Pipe内通过此名称获取处理好的数据。
public class AtzucheProcessor : IPageProcessor
{ public void Process(Page page, ISpider spider) { List<AtzucheModel> list = new List<AtzucheModel>(); var html = page.Selectable.JsonPath("$.data.content").GetValue(); list = JsonConvert.DeserializeObject<List<AtzucheModel>>(html); page.AddResultItem("AtzucheList", list); }}
最后是回调，可在此加入保存数据的代码，至此结束。
public class AtzuchePipe : BasePipeline
{ public override void Process(IEnumerable<ResultItems> resultItems, ISpider spider) { var result = new List<AtzucheModel>(); foreach (var resultItem in resultItems) { Console.WriteLine((resultItem.Results["AtzucheList"] as List<AtzucheModel>).Count); foreach (var item in (resultItem.Results["AtzucheList"] as List<AtzucheModel>)) { result.Add(new AtzucheModel() { carNo = item.carNo }); Console.WriteLine($"{item.carNo}:{item.type} "); } } }}结果图:
总体来说，此框架对新手还是很友好的，灵活写法可以让我们有较多的方式去实现爬虫，因为这个爬虫比较简单，就先写到这里，未来如果可能，会再尝试使用框架内的多线程、代理等功能，如有心得将继续分享，希望能对跟我一样的新手有所帮助，十分感谢。
作者：Grom