lucene 4.6 为数据库建立增量索引

灰太狼 2022-09-19 15:28 229阅读 0赞

首先去官网下载lucene ， 地址：[http://www.apache.org/dyn/closer.cgi/lucene/java/4.6.0][http_www.apache.org_dyn_closer.cgi_lucene_java_4.6.0]  
  
下载IK分词源码,地址 : [ http://code.google.com/p/ik-analyzer/downloads/list][http_code.google.com_p_ik-analyzer_downloads_list]  
  
添加lucene jar包:  
![Center][]  
  
导入分词源码:  
  
![Center 1][]  
  
这里以一个商品表为例,对该表建立索引,并进行查询  
  
商品表对应的bean:

public class Goods implements java.io.Serializable {
    
    	// Fields
    
    	private Integer id;
    	private String name;
    	private String describe;
    	private Timestamp uploadTime;
    	private Double price;
    	private Integer newOld;
    	private String imageName;
    	private Integer userId;
    	private Integer specialGoodsId;
    	private Boolean state;
    	private Integer needSpecialGoodsId;
    	private String needName;
            //....省略getter和setter

为方便以后为数据库其他表建索引,采用模板模式,建一个抽象类,把建索引的方法和  
转化为bean的方法写成抽象方法,并使用泛型,方便子类继承,代码如下:

package com.sms.web.lucene;
    
    import java.io.File;
    import java.io.IOException;
    import java.io.StringReader;
    import java.util.List;
    import org.apache.lucene.analysis.Analyzer;
    import org.apache.lucene.analysis.TokenStream;
    import org.apache.lucene.document.Document;
    import org.apache.lucene.index.DirectoryReader;
    import org.apache.lucene.index.IndexReader;
    import org.apache.lucene.index.IndexWriter;
    import org.apache.lucene.index.IndexWriterConfig;
    import org.apache.lucene.queryparser.classic.QueryParser;
    import org.apache.lucene.search.IndexSearcher;
    import org.apache.lucene.search.Query;
    import org.apache.lucene.search.ScoreDoc;
    import org.apache.lucene.search.highlight.Highlighter;
    import org.apache.lucene.search.highlight.InvalidTokenOffsetsException;
    import org.apache.lucene.search.highlight.QueryScorer;
    import org.apache.lucene.search.highlight.SimpleHTMLFormatter;
    import org.apache.lucene.store.Directory;
    import org.apache.lucene.store.FSDirectory;
    import org.apache.lucene.util.Version;
    import org.wltea.analyzer.lucene.IKAnalyzer;
    
    public abstract class LuceneSearch<T> {
    	public File indexDir; // 存放索引文件的目录
    	protected static Analyzer analyzer = new IKAnalyzer(); // 分词器
    
    	public LuceneSearch(File indexDir) {
    		this.indexDir = indexDir;
    	}
    
    	/**
    	 * 为数据库检索数据创建索引
    	 * 
    	 * @param <T>
    	 */
    	public void createIndex(List<T> items) {
    
    		Directory directory = null;
    		IndexWriter indexWriter = null;
    		try {
    			directory = FSDirectory.open(indexDir);
    			IndexWriterConfig config = new IndexWriterConfig(Version.LUCENE_46, analyzer);
    			config.setOpenMode(IndexWriterConfig.OpenMode.CREATE_OR_APPEND);// 设置打开索引模式为创建或追加
    			indexWriter = new IndexWriter(directory, config);
    			// 装配成document
    			List<Document> docs = getDoc(items);
    			for (Document doc : docs) {
    				indexWriter.addDocument(doc);
    			}
    
    		} catch (IOException e) {
    			e.printStackTrace();
    		} finally {
    			if (indexWriter != null)
    				try {
    					indexWriter.close();
    				} catch (IOException e) {
    					e.printStackTrace();
    				}
    			if (directory != null) {
    				try {
    					directory.close();
    				} catch (IOException e) {
    					e.printStackTrace();
    				}
    			}
    		}
    	}
    
    	/**
    	 * 搜索索引
    	 * 
    	 * @param queryStr
    	 * @param queryField
    	 * @return
    	 */
    	public List<T> search(String queryStr, String queryField) {
    		List<T> hitItem = null;
    		IndexReader reader = null;
    		IndexSearcher indexSearcher = null;
    		try {
    			reader = DirectoryReader.open(FSDirectory.open(indexDir));
    			indexSearcher = new IndexSearcher(reader);
    			// analyzer = new IKAnalyzer();
    			QueryParser parser = new QueryParser(Version.LUCENE_46, queryField, analyzer);
    			Query query = parser.parse(queryStr);
    			ScoreDoc[] hits = indexSearcher.search(query, 100).scoreDocs;
    			hitItem = toBean(indexSearcher, query, hits);
    		} catch (Exception e) {
    			e.printStackTrace();
    		} finally {
    			if (reader != null)
    				try {
    					reader.close();
    				} catch (IOException e) {
    					e.printStackTrace();
    				}
    		}
    
    		return hitItem;
    	}
    
    	/**
    	 * 装配成document对象
    	 * 
    	 * @param goods
    	 * @return
    	 */
    	public abstract List<Document> getDoc(List<T> items);
    
    	/**
    	 * 将搜索结果还原成Bean
    	 * 
    	 * @param indexSearcher
    	 * @param query
    	 * @param hits
    	 * @return
    	 */
    	public abstract List<T> toBean(IndexSearcher indexSearcher, Query query, ScoreDoc[] hits);
    
    	/**
    	 * 高亮设置
    	 * 
    	 * @param query
    	 * @param doc
    	 * @param field
    	 * @return
    	 */
    	protected String toHighlighter(Query query, Document doc, String field) {
    		try {
    			SimpleHTMLFormatter simpleHtmlFormatter = new SimpleHTMLFormatter("<font color=\"blue\">", "</font>");
    			Highlighter highlighter = new Highlighter(simpleHtmlFormatter, new QueryScorer(query));
    			TokenStream tokenStream1 = analyzer.tokenStream("text", new StringReader(doc.get(field)));
    			String highlighterStr = highlighter.getBestFragment(tokenStream1, doc.get(field));
    			return highlighterStr == null ? doc.get(field) : highlighterStr;
    		} catch (IOException e) {
    			e.printStackTrace();
    		} catch (InvalidTokenOffsetsException e) {
    			e.printStackTrace();
    		}
    		return null;
    	}
    }

构建一个子类,继承上面的抽象类,实现器抽象方法:

package com.sms.web.lucene;
    
    import java.io.File;
    import java.io.IOException;
    import java.sql.Timestamp;
    import java.util.ArrayList;
    import java.util.List;
    import org.apache.lucene.document.Document;
    import org.apache.lucene.document.Field;
    import org.apache.lucene.document.FieldType;
    import org.apache.lucene.document.StoredField;
    import org.apache.lucene.search.IndexSearcher;
    import org.apache.lucene.search.Query;
    import org.apache.lucene.search.ScoreDoc;
    
    import com.sms.web.model.Goods;
    
    public class SearchGood extends LuceneSearch<Goods> {
    
    	public SearchGood(File indexDir) {
    		super(indexDir);
    	}
    
    	@Override
    	public List<Document> getDoc(List<Goods> goods) {
    		List<Document> docs = new ArrayList<Document>();
    		FieldType ftIndex = new FieldType(); // 索引类型
    		ftIndex.setIndexed(true); // 设置索引为true
    		ftIndex.setStored(true); // 设置保存为true
    		ftIndex.setTokenized(true); // 设置分词为true
    		for (Goods good : goods) {
    			Document doc = new Document();
    			Document docNeedName = new Document();
    			
    			Field name = new Field("name", good.getName(), ftIndex);
    			Field needName = new Field("needName", good.getNeedName(), ftIndex);
    			Field id = new StoredField("id", good.getId());
    			Field describe = new StoredField("describe", good.getDescribe());
    			Field uploadTime = new StoredField("uploadTime", good.getUploadTime().toString());
    			Field price = new StoredField("price", good.getPrice());
    			Field newOld = new StoredField("newOld", good.getNewOld());
    			Field imageName = new StoredField("imageName", good.getImageName());
    			Field userId = new StoredField("userId", good.getUserId());
    			Field specialGoodsId = new StoredField("specialGoodsId", good.getSpecialGoodsId());
    			Field state = new StoredField("state", good.getState().toString());
    			Field needSpecialGoodsId = new StoredField("needSpecialGoodsId", good.getNeedSpecialGoodsId());
    			//混合名
    			Field mixName1=new Field("mixName", good.getName(), ftIndex);
    			Field mixName2=new Field("mixName", good.getNeedName(), ftIndex);
    			
    			doc.add(name);
    			doc.add(needName);
    			doc.add(id);
    			doc.add(describe);
    			doc.add(uploadTime);
    			doc.add(price);
    			doc.add(newOld);
    			doc.add(imageName);
    			doc.add(userId);
    			doc.add(specialGoodsId);
    			doc.add(state);
    			doc.add(needSpecialGoodsId);
    			
    			doc.add(mixName1);
    			
    			docNeedName.add(mixName2);
    			
    			docs.add(doc);
    			docs.add(docNeedName);
    		}
    		return docs;
    	}
    
    	@Override
    	public List<Goods> toBean(IndexSearcher indexSearcher, Query query, ScoreDoc[] hits) {
    		List<Goods> hitGoods = new ArrayList<Goods>();
    		try {
    			for (int i = 0; i < hits.length; i++) {
    				Goods good = new Goods();
    				Document hitDoc = indexSearcher.doc(hits[i].doc);
    				String id = hitDoc.get("id");
    				// 高亮关键字
    				String name = toHighlighter(query, hitDoc, "name");
    				// 高亮关键字
    				String needName = toHighlighter(query, hitDoc, "needName");
    				String describe = hitDoc.get("describe");
    				String uploadTime = hitDoc.get("uploadTime");
    				String price = hitDoc.get("price");
    				String newOld = hitDoc.get("newOld");
    				String imageName = hitDoc.get("imageName");
    				String userId = hitDoc.get("userId");
    				String specialGoodsId = hitDoc.get("specialGoodsId");
    				String state = hitDoc.get("state");
    				String needSpecialGoodsId = hitDoc.get("needSpecialGoodsId");
    
    				good.setId(Integer.parseInt(id));
    				good.setName(name);
    				good.setDescribe(describe);
    				good.setUploadTime(Timestamp.valueOf(uploadTime));
    				good.setPrice(Double.parseDouble(price));
    				good.setNewOld(Integer.parseInt(newOld));
    				good.setImageName(imageName);
    				good.setUserId(Integer.parseInt(userId));
    				good.setSpecialGoodsId(Integer.parseInt(specialGoodsId));
    				good.setState(Boolean.parseBoolean(state));
    				good.setNeedSpecialGoodsId(Integer.parseInt(needSpecialGoodsId));
    				good.setNeedName(needName);
    				hitGoods.add(good);
    			}
    		} catch (IOException e) {
    			e.printStackTrace();
    		}
    		return hitGoods;
    	}
    
    }

对数据库建立索引:  
从数据库中查找出所有的商品记录,调用上面的createIndex方法进行建索引,  
建完索引后如何维护,也就是说以后数据库中记录发生变化后,索引如何进行更新?  
对于数据库记录只有增加的情况来说,我们可以在表中加1个flag字段,标志是否已  
为其建立了索引,建立索引时把其置为1,再把建索引的方法写成spring的定时任务  
下次建索引时,只为flag为0的建增量索引。  
但是对于数据库的更新，删除记录，如何使索引与其一致，我现在还没想到合适的  
方法（菜鸟一个，功力不够啊！），  
希望广大网友能够提点建议。。。这也是我写这篇博客最主要的目的。

[http_www.apache.org_dyn_closer.cgi_lucene_java_4.6.0]: http://www.apache.org/dyn/closer.cgi/lucene/java/4.6.0
[http_code.google.com_p_ik-analyzer_downloads_list]: http://code.google.com/p/ik-analyzer/downloads/list
[Center]: /images/20220828/cf699228efae40868e59c9c7cb06cce6.png
[Center 1]: /images/20220828/c1eb29d9f7834b3cadb2ac2b7c8e0cbf.png