B2C商城关键技术点总结（站内搜索、定时任务）

1.站内搜索

1.1Lucene.Net建立信息索引　　

             string indexPath = @"E:\xxx\xxx";//索引保存路径
             FSDirectory directory = FSDirectory.Open(new DirectoryInfo(indexPath), new NativeFSLockFactory());
             bool isUpdate = IndexReader.IndexExists(directory);
             if (isUpdate)
             {
                 //如果索引目录被锁定（比如索引过程中程序异常退出），则首先解锁
                 if (IndexWriter.IsLocked(directory))
                 {
                     IndexWriter.Unlock(directory);
                 }
             }
             IndexWriter writer = new IndexWriter(directory, new PanGuAnalyzer(), !isUpdate, Lucene.Net.Index.IndexWriter.MaxFieldLength.UNLIMITED);

             for (int i = ; i <= ; i++)
             {
                 //因为从服务器下载页面有可能失败，为了避免失败时程序终止，所以要处理异常，写入日志
                 //这里能预知的异常是服务器下载失败异常，WebException
                 try
                 {
                     WebClient wc = new WebClient();
                     wc.Encoding = Encoding.UTF8;
                     string url = "http://localhost:3448/Book.aspx?id=" + i;
                     string html = wc.DownloadString(url);

                     HTMLDocumentClass htmlDoc = new HTMLDocumentClass();
                     htmlDoc.designMode = "on"; //不让解析引擎去尝试运行javascript
                     htmlDoc.IHTMLDocument2_write(html);
                     htmlDoc.close();

                     string title = htmlDoc.title;
                     string content = "";
                     if (htmlDoc.getElementById("ctl00_ContentPlaceHolder1_DetailsView1_txtContent") != null)
                     {
                         if (htmlDoc.getElementById("ctl00_ContentPlaceHolder1_DetailsView1_txtContent").innerText != null)
                         {
                             content = htmlDoc.getElementById("ctl00_ContentPlaceHolder1_DetailsView1_txtContent").innerText;
                         }
                     }
                     //为避免重复索引，所以要先删除"url"=url的记录，再重新添加
                     writer.DeleteDocuments(new Term("url", url));

                     Document document = new Document();
                     document.Add(new Field("url", url, Field.Store.YES, Field.Index.NOT_ANALYZED));
                     document.Add(new Field("title", title, Field.Store.YES, Field.Index.ANALYZED, Lucene.Net.Documents.Field.TermVector.WITH_POSITIONS_OFFSETS));
                     document.Add(new Field("content", content, Field.Store.YES, Field.Index.ANALYZED, Lucene.Net.Documents.Field.TermVector.WITH_POSITIONS_OFFSETS));
                     writer.AddDocument(document);

                     logger.Debug("索引" + i + "完毕");
                 }
                 catch (WebException webe)
                 {
                     logger.Error(webe.Message);
                 }
             }
             writer.Close();
             directory.Close();//不要忘了Close，否则索引结果搜不到
             logger.Debug("全部索引完毕");            

1.2盘古分词并高亮

         public List<SearchContentResult> GetSearchContentResult(string kw, int startIndex,int pageSize,  out int count)
         {
             string indexPath = @"E:xxx\xxx\index";
             FSDirectory directory = FSDirectory.Open(new DirectoryInfo(indexPath), new NoLockFactory());
             IndexReader reader = IndexReader.Open(directory, true);
             IndexSearcher searcher = new IndexSearcher(reader);

             //将用户搜索的关键字进行分词
             string[] strs = CommonHelper.FenCi(kw.ToLower());
             PhraseQuery query = new PhraseQuery();
             foreach (string str in strs)
             {
                 query.Add(new Term("content", str));
             }
             query.SetSlop();

             TopScoreDocCollector collector = TopScoreDocCollector.create(, true);
             searcher.Search(query, null, collector);
             count = collector.GetTotalHits();
             ScoreDoc[] docs = collector.TopDocs(startIndex,pageSize).scoreDocs;
             List<SearchContentResult> scs = new List<SearchContentResult>();
             for (int i = ; i < docs.Length; i++)
             {
                 int docId = docs[i].doc;
                 Document doc = searcher.Doc(docId);
                 SearchContentResult sc = new SearchContentResult();
                 sc.Url = doc.Get("url");
                 sc.Title = doc.Get("title");
                 sc.Body = highLight(kw, doc.Get("content"));
                 scs.Add(sc);
             }
             return scs;
         }

         private static String highLight(string keyword, String content)
         {
             PanGu.HighLight.SimpleHTMLFormatter formatter = new PanGu.HighLight.SimpleHTMLFormatter("<font color='red'>", "</font>");
             PanGu.HighLight.Highlighter highlighter = new PanGu.HighLight.Highlighter(formatter, new Segment());
             highlighter.FragmentSize = ;
             string msg = highlighter.GetBestFragment(keyword, content);
             if (string.IsNullOrEmpty(msg))
             {
                 return content;
             }
             else
             {
                 return msg;
             }
         }

2.Quartz.Net定时任务

在Global类中声明一个静态变量

static IScheduler sched;

保证其在系统中是唯一的

             //建立一个Quartz任务
             ISchedulerFactory sf = new StdSchedulerFactory();
             sched = sf.GetScheduler();
             JobDetail job = new JobDetail("job1", "group1", typeof(IndexJob));//IndexJob为实现了IJob接口的类

             Trigger trigger = TriggerUtils.MakeDailyTrigger("trigger", , );
             trigger.JobGroup = "group1";
             trigger.JobName = "job1";

             sched.AddJob(job, true);
             sched.ScheduleJob(trigger);
             sched.Start();

添加任务类，并继承接口

     public class IndexJob : IJob
     {
         private static ILog logger = LogManager.GetLogger(typeof(IndexJob));
         public void Execute(JobExecutionContext context)
         {
             //此处写执行的代码
         }
     }