//
// GET: /News/
public ActionResult Index()
{
//Linq 语法 计算在likes 中ItemID文章的总like数目，也可用EF方法实现，比较麻烦
// int x = db.likes.Count(like => like.ItemId ==101);
/******************************
* 访问rss的地址，读取xml数据
******************************/
rss cars = null;
// System.Net.WebClient client = new WebClient();
// byte[] page = client.DownloadData("http://rss.nytimes.com/services/xml/rss/nyt/US.xml");
// string path = System.Text.Encoding.UTF8.GetString(page);
//string path = "cars.xml";
XmlSerializer serializer = new XmlSerializer(typeof(rss));
//HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create("http://rss.nytimes.com/services/xml/rss/nyt/US.xml");
//使用Cookie设置AllowAutoRedirect属性为false,是解决“尝试自动重定向的次数太多。”的核心
// request.CookieContainer = new CookieContainer();
// request.AllowAutoRedirect = false;
// WebResponse response = (WebResponse)request.GetResponse();
// Stream sm = response.GetResponseStream();
// System.IO.StreamReader streamReader = new System.IO.StreamReader(sm);
//将流转换为字符串
// string html = streamReader.ReadToEnd();
// streamReader.Close();
// TextReader reader = new StreamReader(path);
XmlReader reader = new XmlTextReader("http://rss.nytimes.com/services/xml/rss/nyt/US.xml");
cars = (rss)serializer.Deserialize(reader);
/*var serializer = new XmlSerializer(typeof(rss));
* using (TextReader reader = new StringReader(html))
* {
* cars = (rss)serializer.Deserialize(reader);
* }*/
// reader.Close();
/******************************
* 初始化最新时间newTime
******************************/
DateTime newTime;
if (db.sources.Find("NYTimes") == null)
{
//db.sources.Add(new Models.source("NYTimes", new DateTime(2000,1,1))); //Initialize database
db.sources.Add(new Models.source("NYTimes", DateTime.Parse("Sat, 07 Feb 2015 00:57:00 GMT")));
}
//db.sources.Add(new source { srcName = "NYTimes", newDate = DateTime.Parse("Sat, 07 Feb 2015 00:57:00 GMT") });
//db.SaveChanges();
if (db.sources.Find("NYTimes").newDate.Value < DateTime.Parse("Sat, 07 Feb 2015 00:57:00 GMT"))
{
string httpTime = cars.item[cars.item.Length - 1].pubDate;
newTime = DateTime.Parse(httpTime);
Models.source src = new Models.source("NYTimes", newTime);
db.sources.Add(src);
}
else
{
Models.source src = db.sources.Find("NYTimes");
newTime = src.newDate.Value;
}
/******************************
* 循环添加每一条新闻条目，只添加新条目
******************************/
for (var i = cars.item.Length - 1; i >= 0; i--) //old item store into database first
{
string httpTime = cars.item[i].pubDate;
DateTime time = DateTime.Parse(httpTime);
// 每次添加新条目前，先与source里的最新时间对比
if (time <= newTime) //time值小于最新时间，舍弃
{
continue;
}
else
{
Models.source src = db.sources.Find("NYTimes");
src.newDate = time; //更新时间
}
// description里面会带有<和> 之间的多余内容，例如广告，使用正则表达式可以消除掉
cars.item[i].description = Regex.Replace(cars.item[i].description, "<.*?>", string.Empty);
Models.item item = new Models.item(cars.item[i], time, "NYTimes", 0);
db.items.Add(item); //item include 4 elements
db.SaveChanges(); //save DB before calling other function !!
/**********************************
* 添加每篇文章同时对keyword表和artKey表进行统计
* ********************************/
KeywordAnalyzer ka = new KeywordAnalyzer();
ka.analyze(item); //这里保存的数据库结果，不会传到view的ToList里？TFIDF
ka.TFIDF(item.Id); //随着数据越多，TFIDF效果会越来越精确
/*****************************
* 把结果存进article表中。不能放在子函数，否则传不进View？
*****************************/
var query2 = db.artKeys
.Where(x => x.AId == item.Id)
.OrderByDescending(x => x.TFIDF)
.Take(3); //获得排序最高的三个关键词
string str = "";
foreach (var line in query2)
{
str = str + line.word + ",";
}
db.items.Find(item.Id).keyword = str;
db.SaveChanges();
}
//db.SaveChanges();
return(View(db.items.ToList()));
}
