private static bool IsSameXPath(string xpath1, string xpath2, string shortv)
{
var p1 = XPath.TakeOff(xpath1, shortv);
var p2 = XPath.TakeOff(xpath2, shortv);
return(p1 == p2);
}
/// <summary>
/// 获取从头开始的最大公共子串
/// </summary>
/// <returns></returns>
public static XPath GetMaxCompareXPath(IList <XPath> items)
{
int minlen = items.Min(d => d.Count);
string c = null;
int i = 0;
for (i = 0; i < minlen; i++)
{
for (int index = 0; index < items.Count; index++)
{
XPath path = items[index];
if (index == 0)
{
c = path[i];
}
else
{
if (c != path[i])
{
goto OVER;
}
}
}
}
OVER:
XPath first = items.First().SubXPath(i + 1);
first.RemoveFinalNum();
return(first);
}
private static bool IsSameXPath(string xpath1, string xpath2, string shortv)
{
var p1 = new XPath(xpath1).TakeOff(shortv);
var p2 = new XPath(xpath2).TakeOff(shortv);
return(p1.ToString() == p2.ToString());
}
public static string GetTextNode(this HtmlNode node)
{
var para = new ParaClass();
node.GetTextRootProbability(para);
return(XPath.SubXPath(para.Path, -2));
}
public static string GetTextNode(this HtmlNode node)
{
var para = new ParaClass();
node.GetTextRootProbability(para);
var path = new XPath(para.Path);
return(path.SubXPath(0, path.Count - 2).ToString());
}
public XPath TakeOff(string fullPath)
{
if (string.IsNullOrEmpty(fullPath))
{
return(this);
}
var temp = new XPath(fullPath);
return(SubXPath(temp.Count, Count - temp.Count));
}
public static IEnumerable <List <CrawlItem> > SearchPropertiesSmart(this HtmlDocument doc2,
ICollection <CrawlItem> existItems = null, bool isAttrEnabled = false)
{
if (existItems == null)
{
existItems = new List <CrawlItem>();
}
var shortv = "";
if (existItems.Count > 1)
{
shortv =
XPath.GetMaxCompareXPath(existItems.Select(d => new XPath(d.XPath)).ToList()).ToString();
yield return(GetDiffNodes(doc2, shortv, isAttrEnabled, existItems));
}
else if (existItems.Count == 1)
{
var realPath = new XPath(existItems.First().XPath);
var array =
realPath.SelectAll(d => true)
.Select(d => new XPath(realPath.Take(d)).ToString()).ToList();
var dict = new Dictionary <string, double>();
foreach (var item in array)
{
GetTableRootProbability(
doc2.DocumentNode.SelectSingleNode(item)
.ChildNodes.Where(d2 => d2.Name.Contains("#") == false)
.ToList(), dict, false);
}
foreach (
var item in
dict.OrderByDescending(d => d.Value))
{
shortv = item.Key;
yield return(GetDiffNodes(doc2, shortv, isAttrEnabled, existItems));
}
}
else
{
var dict = new Dictionary <string, double>();
GetTableRootProbability(
doc2.DocumentNode.ChildNodes.Where(d => d.Name.Contains("#") == false).ToList(), dict, true);
IEnumerable <KeyValuePair <string, double> > p = dict.OrderByDescending(d => d.Value);
foreach (var keyValuePair in p)
{
var items = GetDiffNodes(doc2, keyValuePair.Key, isAttrEnabled, existItems);
if (items.Count > 1)
{
yield return(items);
}
}
}
}
/// <summary>
/// 从批量集合中获取数据
/// </summary>
/// <param name="doc"></param>
/// <param name="crawItem"></param>
/// <param name="root"></param>
/// <param name="document"></param>
public static void GetDataFromXPath(this HtmlDocument doc, CrawlItem crawItem, string root,
IFreeDocument document)
{
var result = doc.DocumentNode.GetDataFromXPath(XPath.TakeOff(crawItem.XPath, root),
crawItem.IsHTML);
if (result != null)
{
document.SetValue(crawItem.Name, result);
}
}
public static string CompileCrawItems(this HtmlDocument doc2, IList <CrawlItem> crawlItem)
{
var shortv =
XPath.GetMaxCompareXPath(crawlItem.Select(d => new XPath(d.XPath)).ToList()).ToString();
if (!string.IsNullOrEmpty(shortv))
{
crawlItem.Execute(d => d.XPath = new XPath(d.XPath).TakeOff(shortv).ToString());
return(shortv);
}
return("");
}
private static CrawTarget getCrawTarget(List <CrawlItem> items, string root = null)
{
if (items.Count > 1)
{
return(new CrawTarget(items));
}
else if (items.Count == 1 && string.IsNullOrEmpty(root) == false)
{
var child = XPath.TakeOff(items[0].XPath, root);
items[0].XPath = child;
return(new CrawTarget(items, root));
}
return(null);
}
/// <summary>
/// 计算可能是列表根节点的概率，同时将值保存在dict中。
/// </summary>
/// <param name="node"></param>
/// <param name="dict"></param>
private static void GetTableRootProbability(IList <HtmlNode> nodes, Dictionary <string, double> dict,
bool haschild)
{
if (nodes.Count == 0)
{
return;
}
var node = nodes[0];
var xpath = XPath.RemoveFinalNum(node.XPath);
if (haschild)
{
foreach (var htmlNode in nodes)
{
GetTableRootProbability(htmlNode.ChildNodes.Where(d => d.Name.Contains("#") == false).ToList(), dict,
haschild);
}
}
var avanode = nodes.ToList();
if (avanode.Count < 3)
{
return;
}
//if (avanode.Count(d => d.Name == avanode[1].Name) < avanode.Count*0.7)
// return;
var childCount = (double)avanode.Count;
var childCounts = avanode.Select(d => (double)d.ChildNodes.Count).ToArray();
var v = childCounts.Variance();
//TODO: 此处需要一个更好的手段，因为有效节点往往是间隔的
if (v > 100)
{
return;
}
var leafCount = avanode.Last().GetLeafNodeCount();
var value = (childCount * PM25 + leafCount) * (v == 0 ? 2 : (Math.Log10((100 - v) / 100)));
if (xpath.Contains("你"))
{
Console.WriteLine(xpath);
}
dict.SetValue(xpath, value);
}
public override bool Init(IEnumerable <IFreeDocument> docus)
{
base.Init(docus);
if (Crawler == null)
{
return(false);
}
IsMultiYield = true;
xpaths = Crawler.CrawlItems.GroupBy(d => d.Name).Select(d =>
{
var column = d.Key;
var path = XPath.GetMaxCompareXPath(d.Select(d2 => d2.XPath).ToList());
return(new { Column = column, XPath = path });
}).ToDictionary(d => d.Column, d => d.XPath);
return(true);
}
/// <summary>
/// 计算可能是列表根节点的概率，同时将值保存在dict中。
/// </summary>
/// <param name="node"></param>
/// <param name="dict"></param>
private static void GetTableRootProbability(IList <HtmlNode> nodes, Dictionary <string, double> dict,
bool haschild)
{
if (nodes.Count == 0)
{
return;
}
var node = nodes[0];
var xpath = new XPath(node.XPath).RemoveFinalNum().ToString();
if (haschild)
{
foreach (var htmlNode in nodes)
{
GetTableRootProbability(htmlNode.ChildNodes.Where(d => d.Name.Contains("#") == false).ToList(), dict,
haschild);
}
}
var avanode = nodes.ToList();
if (avanode.Count < 3)
{
return;
}
if (avanode.Count(d => d.Name == avanode[1].Name) < avanode.Count * 0.7)
{
return;
}
var childCount = (double)avanode.Count;
var childCounts = avanode.Select(d => (double)d.ChildNodes.Count).ToArray();
var v = childCounts.Variance();
//TODO: 此处需要一个更好的手段，因为有效节点往往是间隔的
if (v > 5)
{
return;
}
var leafCount = avanode.First().GetLeafNodeCount();
var value = childCount * PM25 + leafCount;
dict.SetValue(xpath, value);
}
/// <summary>
/// 从XPath获取数据
/// </summary>
/// <param name="doc"></param>
/// <param name="path"></param>
/// <param name="ishtml"></param>
/// <returns></returns>
public static string GetDataFromXPath(this HtmlNode doc, string path, bool ishtml = false)
{
if (!string.IsNullOrEmpty(path))
{
HtmlNode p2 = null;
try
{
p2 = doc.SelectSingleNode(path);
}
catch (Exception ex)
{
}
if (p2 == null)
{
return(null);
}
var paths = path.Split('/');
var last = paths[paths.Length - 1];
if (last.Any() && last.Contains("@") && last.Contains("[1]")) //标签数据
{
var name = XPath.GetAttributeName(last.Split('@', '[')[1]);
if (p2.HasAttributes)
{
var a = p2.Attributes.FirstOrDefault(d => d.Name == name);
return(a.Value.Trim());
}
}
else if (ishtml)
{
return(p2.InnerHtml);
}
else
{
return(p2.GetNodeText());
}
}
return(null);
}
public static IEnumerable <CrawTarget> SearchPropertiesSmart(this HtmlDocument doc2,
ICollection <CrawlItem> existItems = null, string rootPath = null, bool isAttrEnabled = false)
{
if (existItems == null)
{
existItems = new List <CrawlItem>();
}
var shortv = "";
var dict = new Dictionary <string, double>();
if (string.IsNullOrEmpty(rootPath))
{
if (existItems.Count > 1)
{
shortv =
XPath.GetMaxCompareXPath(existItems.Select(d => d.XPath));
var items = GetDiffNodes(doc2, shortv, isAttrEnabled, existItems, 1);
var target = getCrawTarget(items, shortv);
if (target != null)
{
yield return(target);
}
yield break;
}
if (existItems.Count == 1)
{
var realPath = existItems.First().XPath;
var items = XPath.Split(realPath);
var array =
items.SelectAll(d => true)
.Select(d => XPath.SubXPath(realPath, d)).ToList();
foreach (var item in array)
{
GetTableRootProbability(
doc2.DocumentNode.SelectSingleNode(item)
.ChildNodes.Where(d2 => d2.Name.Contains("#") == false)
.ToList(), dict, false);
}
}
else
{
GetTableRootProbability(
doc2.DocumentNode.ChildNodes.Where(d => d.Name.Contains("#") == false).ToList(), dict, true);
}
if (existItems.Count < 2)
{
IEnumerable <KeyValuePair <string, double> > p = dict.OrderByDescending(d => d.Value);
foreach (var keyValuePair in p)
{
var items = GetDiffNodes(doc2, keyValuePair.Key, isAttrEnabled, existItems, 4);
var target = getCrawTarget(items, keyValuePair.Key);
if (target != null)
{
yield return(target);
}
}
}
}
else
{
var items = GetDiffNodes(doc2, rootPath, isAttrEnabled, new List <CrawlItem>());
if (items.Count > 0)
{
var root = doc2.DocumentNode.SelectSingleNode(rootPath);
foreach (var crawlItem in items)
{
crawlItem.XPath = XPath.TakeOff(crawlItem.XPath, root.XPath);
}
var target = getCrawTarget(items, rootPath);
if (target != null)
{
yield return(target);
}
}
}
}
public static IEnumerable <CrawTarget> SearchPropertiesSmart(this HtmlDocument doc2,
ICollection <CrawlItem> existItems = null, string rootPath = null, bool isAttrEnabled = false)
{
if (existItems == null)
{
existItems = new List <CrawlItem>();
}
var shortv = "";
var dict = new Dictionary <string, double>();
if (string.IsNullOrEmpty(rootPath))
{
var isForceItemOne = false; //强制进入只有一个属性的模式
if (existItems.Count > 1)
{
shortv =
XPath.GetMaxCompareXPath(existItems.Select(d => d.XPath));
var nodes = doc2.DocumentNode.SelectNodes(shortv);
if (nodes == null || nodes.Count == 0)
{
yield break;
}
if (nodes.Count == 1)
{
isForceItemOne = true;
}
else
{
var items = GetDiffNodes(doc2, shortv, isAttrEnabled, existItems, 1);
var target = getCrawTarget(items, shortv);
if (target != null)
{
yield return(target);
}
}
}
if (isForceItemOne || existItems.Count == 1)
{
var realPath = existItems.First().XPath;
var items = XPath.Split(realPath);
var array =
items.SelectAll(d => true)
.Select(d => XPath.SubXPath(realPath, d)).ToList();
foreach (var item in array)
{
GetTableRootProbability(
doc2.DocumentNode.SelectSingleNode(item)
.ChildNodes.Where(d2 => d2.Name.Contains("#") == false)
.ToList(), dict, false);
}
}
else
{
GetTableRootProbability(
doc2.DocumentNode.ChildNodes.Where(d => d.Name.Contains("#") == false).ToList(), dict, true);
}
if (isForceItemOne || existItems.Count < 2)
{
IEnumerable <KeyValuePair <string, double> > p = dict.OrderByDescending(d => d.Value);
foreach (var keyValuePair in p)
{
var items = GetDiffNodes(doc2, keyValuePair.Key, isAttrEnabled, existItems, 4);
if (items.Count == 0)
{
continue;
}
var target = getCrawTarget(items, keyValuePair.Key);
var rootNode = doc2.DocumentNode.SelectSingleNode(keyValuePair.Key).ParentNode;
if (rootNode == null)
{
continue;
}
target.Html = rootNode.InnerHtml;
target.Text = rootNode.InnerText;
target.NodeCount = doc2.DocumentNode.SelectNodes(keyValuePair.Key).Count;
target.Score = keyValuePair.Value;
target.ColumnCount = items.Count;
yield return(target);
}
}
}
else
{
var items = GetDiffNodes(doc2, rootPath, isAttrEnabled, new List <CrawlItem>());
if (items.Count > 0)
{
var root = doc2.DocumentNode.SelectSingleNode(rootPath);
var xpath = XPath.RemoveFinalNum(root.XPath);
var target = getCrawTarget(items, xpath);
target.RootXPath = rootPath;
yield return(target);
}
}
}
/// <summary>
/// find different text and return it name and xpath
/// </summary>
/// <param name="isAttrEnabled">是否抓取标签中的数据</param>
/// <returns></returns>
private static bool GetDiffNodes(List <HtmlNode> nodes, List <CrawlItem> result, List <List <string> > buffers,
bool isAttrEnabled)
{
var isChildContainInfo = false;
var node1 = nodes.First();
var node2 = nodes[1];
if (node1.ChildNodes.Count == 1 && node1.ChildNodes[0].NodeType == HtmlNodeType.Text)
{
var row = nodes.Select(d => d.SelectSingleNode(d.XPath))
.Where(d => d != null).Select(d => d.InnerText.Trim()).ToList();
if (row.Any(d => CompareString(d, node1.InnerText) == false))
{
var name = node1.SearchPropertyName(result) ?? "属性" + result.Count;
if (buffers.Any(d => ListEqual(d, row)))
{
return(true);
}
var crawlItem = new CrawlItem
{
Name = name,
SampleData1 = node1.InnerText,
XPath = result.Count % 2 == 0 ? node1.XPath : node2.XPath
};
result.Add(crawlItem);
buffers.Add(row);
return(true);
}
return(false);
}
foreach (var nodechild1 in node1.ChildNodes)
{
if (nodechild1.XPath.Contains("#"))
{
continue;
}
var path = new XPath(nodechild1.XPath).TakeOff(node1.XPath).ToString();
var nodechild2 =
nodes.Select(d => d.SelectSingleNode(d.XPath + path)).Where(d => d != null).ToList();
if (nodechild2.Count == 1)
{
continue;
}
isChildContainInfo |= GetDiffNodes(nodechild2, result, buffers, isAttrEnabled);
}
if (isAttrEnabled == false)
{
return(isChildContainInfo);
}
foreach (var attribute in node1.Attributes)
{
var attr1 = attribute.Value;
;
var row = nodes.Select(d => d.SelectSingleNode(d.XPath))
.Where(d => d != null).Where(d => d.Attributes.Contains(attribute.Name)).Select(d => d.Attributes[attribute.Name].Value).ToList();
if (row.Any(d => CompareString(d, attr1) == false))
{
if (buffers.Any(d => ListEqual(d, row)))
{
return(isChildContainInfo);
}
var name = node1.SearchPropertyName(result);
if (name != null)
{
name += '_' + attribute.Name;
}
else
{
name = "属性" + result.Count;
}
var craw = new CrawlItem {
Name = name, SampleData1 = attr1, XPath = attribute.XPath
};
result.Add(craw);
}
}
return(isChildContainInfo);
}
public static List <FreeDocument> GetDataFromXPath(this HtmlDocument doc2, IList <CrawlItem> crawlItems,
ListType type = ListType.List, string rootXPath = "")
{
if (crawlItems.Count == 0)
{
return(new List <FreeDocument>());
}
var documents = new List <FreeDocument>();
switch (type)
{
case ListType.List:
var root = "";
var takeoff = "";
if (string.IsNullOrEmpty(rootXPath))
{
root =
XPath.GetMaxCompareXPath(crawlItems.Select(d => new XPath(d.XPath)).ToList()).ToString();
takeoff = root;
}
else
{
root = rootXPath;
}
var nodes = doc2.DocumentNode.SelectNodes(root);
if (nodes == null)
{
break;
}
foreach (var node in nodes)
{
var document = new FreeDocument();
foreach (var r in crawlItems)
{
string path;
if (string.IsNullOrEmpty(takeoff))
{
path = node.XPath + r.XPath;
}
else
{
path = node.XPath + new XPath(r.XPath).TakeOff(takeoff);
}
var result = node.GetDataFromXPath(path, r.IsHTML);
document.SetValue(r.Name, result);
}
documents.Add(document);
}
return(documents);
case ListType.One:
var freeDocument = new FreeDocument();
foreach (var r in crawlItems)
{
doc2.GetDataFromXPath(r, freeDocument);
}
return(new List <FreeDocument> {
freeDocument
});
}
return(new List <FreeDocument>());
}
/// <summary>
/// find different text and return it name and xpath
/// </summary>
/// <param name="isAttrEnabled">是否抓取标签中的数据</param>
/// <returns></returns>
private static bool GetDiffNodes(List <HtmlNode> nodes, List <CrawlItem> result, List <List <string> > buffers,
bool isAttrEnabled)
{
var isChildContainInfo = false;
var len = nodes.Count;
var node1 = nodes[Random.Next(0, len / 2)];
var node2 = nodes[Random.Next(len / 2, len)];
if (node1.ChildNodes.Count == 1 && node1.ChildNodes[0].NodeType == HtmlNodeType.Text)
{
var row = nodes.Select(d => d.SelectSingleNode(d.XPath))
.Where(d => d != null).Select(d => d.InnerText.Trim()).ToList();
if (row.Any(d => CompareString(d, node1.InnerText) == false))
{
var name = node1.SearchPropertyName(result) ?? "属性" + result.Count;
if (buffers.Any(d => ListEqual(d, row)))
{
return(true);
}
var crawlItem = new CrawlItem
{
Name = name,
SampleData1 = node1.InnerText,
XPath = result.Count % 2 == 0 ? node1.XPath : node2.XPath
};
result.Add(crawlItem);
buffers.Add(row);
return(true);
}
return(false);
}
foreach (var nodechild1 in node1.ChildNodes)
{
if (nodechild1.XPath.Contains("#"))
{
continue;
}
var path = XPath.TakeOff(nodechild1.XPath, node1.XPath);
var fail = false;
var nodechild2 =
nodes.Select(d =>
{
if (fail)
{
return(null);
}
try
{
var node = d.SelectSingleNode(d.XPath + path);
return(node);
}
catch (Exception)
{
fail = true;
return(null);
}
}).Where(d => d != null && fail == false).ToList();
if (nodechild2.Count < 2 || fail)
{
continue;
}
isChildContainInfo |= GetDiffNodes(nodechild2, result, buffers, isAttrEnabled);
}
if (isAttrEnabled == false)
{
return(isChildContainInfo);
}
foreach (var attribute in node1.Attributes)
{
var attr1 = attribute.Value;
;
var row = nodes.Select(d =>
{
try
{
return(d.SelectSingleNode(d.XPath));
}
catch (Exception ex)
{
XLogSys.Print.Error("XPath表达式编写错误： " + d.XPath);
return(null);
}
})
.Where(d => d != null)
.Where(d => d.Attributes.Contains(attribute.Name))
.Select(d => d.Attributes[attribute.Name].Value)
.ToList();
if (row.Any(d => CompareString(d, attr1) == false))
{
if (buffers.Any(d => ListEqual(d, row)))
{
return(isChildContainInfo);
}
var name = node1.SearchPropertyName(result);
if (name != null)
{
name += '_' + attribute.Name;
}
else
{
name = "属性" + result.Count;
}
var craw = new CrawlItem {
Name = name, SampleData1 = attr1, XPath = attribute.XPath
};
result.Add(craw);
}
}
return(isChildContainInfo);
}
