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:xxxxxx";//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 = 4939; i <= 6087; 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:xxxxxxindex";
            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(100);

            TopScoreDocCollector collector = TopScoreDocCollector.create(2000, 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 = 0; 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 = 500;
            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", 10, 46);
            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
        }
    }