實時索引管理類IndexManager · Lucene案例開發

轉載請注明出處：[http://blog.csdn.net/xiaojimanman/article/details/44015983](http://blog.csdn.net/xiaojimanman/article/details/44015983) [http://www.llwjy.com/blogdetail/5757ce8c007754704b563dd6a47ca1ca.html](http://www.llwjy.com/blogdetail/5757ce8c007754704b563dd6a47ca1ca.html) 個人的博客小站也搭建成功，網址：[www.llwjy.com](http://www.llwjy.com) ，歡迎大家來吐槽~ 在前一篇博客中，對實時索引的實現原理做了一些簡單的介紹，這里就介紹下，如何利用Lucene來實現索引的管理（Lucene中已經實現了大部分的功能，我們只需要對其再次封裝即可）。 **逐個擊破** 在Lucene4.3.1中，實現實時索引時，需要將IndexWrite的相關操作委托給TrackingIndexWriter來處理，具體代碼實現如下： ps:關于如何創建索引這里就不再介紹了，可以參照之前的博客或者該博客后面的完整代碼。 ~~~ this.trackingIndexWriter = new TrackingIndexWriter(this.indexWriter); ~~~ 同時初始化索引管理對象，代碼如下： ~~~ this.nrtManager = new NRTManager(this.trackingIndexWriter, new SearcherFactory()); ~~~ 到這里還需要開啟兩個守護線程：內存索引重讀線程和內存數據commit線程。內存索引重讀線程執行的頻率也就是實時索引的時差，由于內存中的數據不會太多，所以這個延時一般也就是在十幾毫秒左右；內存數據commit線程是將內存中的數據寫到磁盤上，不至于數據丟失，如果研究過Lucene源碼的童鞋也許會發現，即使你不執行commit操作，到內存中的數據達到一定的程度，也會將一部分數據寫到磁盤上，只不過重啟服務這部分數據就丟失了同時還會造成一系列的問題，[http://bbs.csdn.net/topics/390677902](http://bbs.csdn.net/topics/390677902) 這個地址下就是commit線程死掉之后造成的一系列問題，感興趣的童鞋可以了解下。內存重讀線程我們只需要配置下參數啟動即可，代碼如下： ~~~ this.nrtManagerReopenThread = new NRTManagerReopenThread(this.nrtManager, indexReopenMaxStaleSec, indexReopenMinStaleSec); this.nrtManagerReopenThread.setName("NRTManager Reopen Thread"); this.nrtManagerReopenThread.setPriority(Math.min(Thread.currentThread().getPriority()+2, Thread.MAX_PRIORITY)); this.nrtManagerReopenThread.setDaemon(true); this.nrtManagerReopenThread.start(); ~~~ 內存數據commit線程需要自己寫代碼實現，然后啟動該線程即可，代碼如下： ~~~ private class IndexCommitThread extends Thread{ private boolean flag; public IndexCommitThread(String name){ super(name); } @SuppressWarnings("deprecation") public void run(){ flag = true; while(flag) { try { indexWriter.commit(); if (bprint) { System.out.println(new Date().toLocaleString() + "\t" + IndexManagerName + "\tcommit"); } TimeUnit.SECONDS.sleep(indexCommitSeconds); } catch (IOException e) { e.printStackTrace(); } catch (InterruptedException e1) { e1.printStackTrace(); } } } } ~~~ ~~~ this.indexCommitThread = new IndexCommitThread(IndexManagerName + "Index Commit Thread"); this.indexCommitThread.setDaemon(true); this.indexCommitThread.start(); ~~~ 那又如何像普通的索引那樣使用IndexSearcher呢？當然NrtManager類也提供了相關的方法，可以獲取最新可用的IndexSearcher，代碼如下： ~~~ public IndexSearcher getIndexSearcher(){ try { return this.nrtManager.acquire(); } catch (IOException e) { e.printStackTrace(); return null; } } ~~~ 當然在使用之后別忘記釋放，代碼如下： ~~~ public void release(IndexSearcher searcher){ try { nrtManager.release(searcher); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } ~~~ **另類單例模式** 在之前的博客中，我也多次提到，加載索引是一個相當消耗資源的事情，所以我們不可能每一次索引操作都加載一次索引，所以我們就必須使用單例模式來實現IndexManager類。這里的單例模式又和我們常見的單例模式有所區別，普通的單例模式該類只有一個對象，這里的單例模式是該類有多個對象，下面就簡單的介紹下此處另類的單例模式。通過前一篇博客最后，你也許會注意到，系統中關于索引的配置信息是存在HashSet對象中，這也就是說這里IndexManager類會實例化多少次取決于HashSet對象，也就是你配置文件讓他實例化多少次就會實例化多少次。既然這樣，怎么還能叫單例模式呢？這里的單例是索引的單例，也就是說一個索引只有一個IndexManager對象，不會存在兩個IndexManager對象去操作同一個索引的情況。具體代碼實現如下： ~~~ /** * Initialization on Demand Holder式初始化IndexManager */ private static class LazyLoadIndexManager { private static final HashMap<String, IndexManager> indexManager = new HashMap<String, IndexManager>(); static { for (ConfigBean configBean : IndexConfig.getConfigBean()) { indexManager.put(configBean.getIndexName(), new IndexManager(configBean)); } } } /** *@Description: IndexManager私有構造方法 *@Author: lulei *@Version: 1.1.0 */ private IndexManager(ConfigBean configBean){ //... } public static IndexManager getIndexManager(String indexName){ return LazyLoadIndexManager.indexManager.get(indexName); } ~~~ 這樣我們就可以通過索引名獲取到該索引的IndexManager對象。 **廬山真面目** 說了這么多，下面就把IndexManager的源碼附在最后，感興趣的童鞋可以試試（里面還有一些其他的方法，相信不用介紹也都可以看的懂） ~~~ /** *@Description: 索引管理類 */ package com.lulei.lucene.index.manager; import java.io.File; import java.io.IOException; import java.util.Date; import java.util.HashMap; import java.util.concurrent.TimeUnit; import org.apache.lucene.analysis.Analyzer; import org.apache.lucene.index.IndexWriter; import org.apache.lucene.index.IndexWriterConfig; import org.apache.lucene.index.IndexWriterConfig.OpenMode; import org.apache.lucene.search.IndexSearcher; import org.apache.lucene.search.NRTManager; import org.apache.lucene.search.NRTManager.TrackingIndexWriter; import org.apache.lucene.search.NRTManagerReopenThread; import org.apache.lucene.search.SearcherFactory; import org.apache.lucene.store.Directory; import org.apache.lucene.store.NIOFSDirectory; import org.apache.lucene.util.Version; import com.lulei.lucene.index.model.ConfigBean; import com.lulei.lucene.index.model.IndexConfig; public class IndexManager { private IndexWriter indexWriter; //更新索引文件的IndexWriter private TrackingIndexWriter trackingIndexWriter; //索引文件采用的分詞器 private Analyzer analyzer; //索引管理對象 private NRTManager nrtManager; //索引重讀線程 private NRTManagerReopenThread nrtManagerReopenThread; //索引寫入磁盤線程 private IndexCommitThread indexCommitThread; //索引地址 private String indexPath; //索引重讀最大、最小時間間隔 private double indexReopenMaxStaleSec; private double indexReopenMinStaleSec; //索引commit時間 private int indexCommitSeconds; //索引名 private String IndexManagerName; //commit時是否輸出相關信息 private boolean bprint = true; /** * Initialization on Demand Holder式初始化IndexManager */ private static class LazyLoadIndexManager { private static final HashMap<String, IndexManager> indexManager = new HashMap<String, IndexManager>(); static { for (ConfigBean configBean : IndexConfig.getConfigBean()) { indexManager.put(configBean.getIndexName(), new IndexManager(configBean)); } } } /** *@Description: IndexManager私有構造方法 *@Author: lulei *@Version: 1.1.0 */ private IndexManager(ConfigBean configBean){ //設置相關屬性 analyzer = configBean.getAnalyzer(); indexPath = configBean.getIndexPath(); IndexManagerName = configBean.getIndexName(); indexReopenMaxStaleSec = configBean.getIndexReopenMaxStaleSec(); indexReopenMinStaleSec = configBean.getIndexReopenMinStaleSec(); indexCommitSeconds = configBean.getIndexCommitSeconds(); bprint = configBean.isBprint(); String indexFile = indexPath + IndexManagerName + "/"; //創建或打開索引 IndexWriterConfig indexWriterConfig = new IndexWriterConfig(Version.LUCENE_43, analyzer); indexWriterConfig.setOpenMode(OpenMode.CREATE_OR_APPEND); Directory directory = null; try { directory = NIOFSDirectory.open(new File(indexFile)); if (IndexWriter.isLocked(directory)){ IndexWriter.unlock(directory); } this.indexWriter = new IndexWriter(directory, indexWriterConfig); this.trackingIndexWriter = new TrackingIndexWriter(this.indexWriter); this.nrtManager = new NRTManager(this.trackingIndexWriter, new SearcherFactory()); } catch(IOException e){ e.printStackTrace(); } //開啟守護進程 this.setThread(); } /** * @Author: lulei * @Description: 創建索引管理線程 */ private void setThread(){ this.nrtManagerReopenThread = new NRTManagerReopenThread(this.nrtManager, indexReopenMaxStaleSec, indexReopenMinStaleSec); this.nrtManagerReopenThread.setName("NRTManager Reopen Thread"); this.nrtManagerReopenThread.setPriority(Math.min(Thread.currentThread().getPriority()+2, Thread.MAX_PRIORITY)); this.nrtManagerReopenThread.setDaemon(true); this.nrtManagerReopenThread.start(); this.indexCommitThread = new IndexCommitThread(IndexManagerName + "Index Commit Thread"); this.indexCommitThread.setDaemon(true); this.indexCommitThread.start(); } /** * @return * @Author:lulei * @Description: 重啟索引commit線程 */ public String setCommitThread() { try { if (this.indexCommitThread.isAlive()){ return "is alive"; } this.indexCommitThread = new IndexCommitThread(IndexManagerName + "Index Commit Thread"); this.indexCommitThread.setDaemon(true); this.indexCommitThread.start(); } catch (Exception e) { e.printStackTrace(); return "failed"; } return "reload"; } /** *@Description: 索引commit線程 *@Author: lulei *@Version: 1.1.0 */ private class IndexCommitThread extends Thread{ private boolean flag; public IndexCommitThread(String name){ super(name); } @SuppressWarnings("deprecation") public void run(){ flag = true; while(flag) { try { indexWriter.commit(); if (bprint) { System.out.println(new Date().toLocaleString() + "\t" + IndexManagerName + "\tcommit"); } TimeUnit.SECONDS.sleep(indexCommitSeconds); } catch (IOException e) { e.printStackTrace(); } catch (InterruptedException e1) { e1.printStackTrace(); } } } } /** * @return IndexManager * @Author: lulei * @Description: 獲取索引管理類 */ public static IndexManager getIndexManager(String indexName){ return LazyLoadIndexManager.indexManager.get(indexName); } /** * @@Description:釋放IndexSearcher資源 * @param searcher */ public void release(IndexSearcher searcher){ try { nrtManager.release(searcher); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } /** * @return IndexSearcher * @Author: lulei * @Description: 返回IndexSearcher對象，使用完之后，調用release方法進行釋放 */ public IndexSearcher getIndexSearcher(){ try { return this.nrtManager.acquire(); } catch (IOException e) { e.printStackTrace(); return null; } } public NRTManager getNRTManager(){ return this.nrtManager; } public IndexWriter getIndexWriter(){ return this.indexWriter; } public TrackingIndexWriter getTrackingIndexWriter(){ return this.trackingIndexWriter; } public Analyzer getAnalyzer(){ return analyzer; } /** * @return * @Author: lulei * @Description: 獲取索引中的記錄條數 */ public int getIndexNum(){ return indexWriter.numDocs(); } } ~~~ ps:最近發現其他網站可能會對博客轉載，上面并沒有源鏈接，如想查看更多關于 [基于lucene的案例開發](http://blog.csdn.net/xiaojimanman/article/category/2841877) 請[點擊這里](http://blog.csdn.net/xiaojimanman/article/category/2841877)。或訪問網址http://blog.csdn.net/xiaojimanman/article/category/2841877 或?[www.llwjy.com](http://www.llwjy.com)