lucene 在项目中的使用
开源全文搜索工具包Lucene3.0.1的使用。
项目环境Struts2 (2.18)+Hibernate(3.0)+Spring(2.5) JDK:1.6 IDE:myEclipse 8.5
项目需求：把站内发布的新闻进行全文解索
新闻实体News
public class News {
private int id;
/**标题*/
private String title;
/**内容*/
private String contents;
setters();
getters();
}新闻实体的luceneDaopackage com.hkrt.dao;
import com.hkrt.domain.LuceneSearchResult;
import com.hkrt.domain.News;
public interface NewsLuceneDao {
public static final String FIELD_ID="id";
public static final String FIELD_TITLE = "title";
public static final String FIELD_CONTENTS = "contents";
// 索引存放目录
public static final String INDEX_DIR = Thread.currentThread().getContextClassLoader().getResource("").getPath()+"index_dir";
/**
* 对所有文件进行重新索引
*/
public void rebuildAllIndex();
/**
* 对指定上传文件对象进行索引并追加到已有的索引文件中
* @param news
*/
public void doIndexSingle(News news);
/**
* 根据关键字搜索,返回符合条件的分页数据
* @param keyword 关键字
* @param pageNo 起始页
* @param pageSize 每页要显示的记录数
* @return LuceneSearchResult对象
*/
public LuceneSearchResult<News> doSeacher(String keyword, int pageNo,int pageSize);
/**
* 更新文件的索引
* @param news
*/
public void updateIndex(News news);
/**
* 根据文件id删除索引
* @param id
*/
public void deleteIndex(Integer id);
}新闻lucene dao的实现package com.hkrt.dao.impl;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.CorruptIndexException;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.Term;
import org.apache.lucene.queryParser.MultiFieldQueryParser;
import org.apache.lucene.queryParser.ParseException;
import org.apache.lucene.search.BooleanClause;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.TopDocs;
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.SimpleFragmenter;
import org.apache.lucene.search.highlight.SimpleHTMLFormatter;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.store.LockObtainFailedException;
import org.apache.lucene.util.Version;
import com.hkrt.dao.NewsDao;
import com.hkrt.dao.NewsLuceneDao;
import com.hkrt.domain.LuceneSearchResult;
import com.hkrt.domain.News;
public class NewsLuceneDaoImpl implements NewsLuceneDao {
private NewsDao newsDao;
/** 获取语法解析器 */
public Analyzer getAnalyzer() {
return new StandardAnalyzer(Version.LUCENE_30);
}
/** 打开索引的存放目录 */
public Directory openDirectory() {
try {
System.out.println(new File(INDEX_DIR) + "-------打开索引--------------");
return FSDirectory.open(new File(INDEX_DIR));
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
/** 对文件的指定属性映射成域,返回文件文档对象 */
public Document createForumuploadDocument(News news) {
Document doc = new Document(); // 创建一个文档对象
//id 域
Field field = new Field(FIELD_ID,String.valueOf(news.getId()),Field.Store.YES, Field.Index.NOT_ANALYZED);
doc.add(field);
// title域
Field field1 = new Field(FIELD_TITLE, String.valueOf(news.getTitle()),Field.Store.YES, Field.Index.ANALYZED);
doc.add(field1);
// content域
Field field2 = new Field(FIELD_CONTENTS, String.valueOf(news.getContents()), Field.Store.YES, Field.Index.ANALYZED);
doc.add(field2);
return doc;
}
public void deleteIndex(Integer id) {
IndexReader ir = null;
try {
ir = IndexReader.open(this.openDirectory(), false); //打开指定目录下索引文件的索引读取器
ir.deleteDocuments(new Term(FIELD_ID,String.valueOf(id))); //删除符合条件的Document
} catch (IOException e) {
e.printStackTrace();
}finally{
if(ir != null){
try {
ir.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
@Override
public void doIndexSingle(News news) {
//创建索引写入器
IndexWriter indexWriter = null;
try {
indexWriter = new IndexWriter(openDirectory(), getAnalyzer(),false, IndexWriter.MaxFieldLength.UNLIMITED);
Document doc = this.createForumuploadDocument(news);
indexWriter.addDocument(doc);
indexWriter.optimize(); // 对索引进行优化
} catch (CorruptIndexException e) {
e.printStackTrace();
} catch (LockObtainFailedException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (indexWriter != null) {
indexWriter.close(); // 关闭IndexWriter,把内存中的数据写到文件
}
} catch (CorruptIndexException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
@Override
public LuceneSearchResult<News> doSeacher(String keyword, int pageNo,int pageSize) {
LuceneSearchResult<News> lsr = new LuceneSearchResult<News>();
lsr.setPageNo(pageNo);
lsr.setPageSize(pageSize);
lsr.setKeyword(keyword);
IndexSearcher searcher = null;
try {
// 创建一个索引搜索器
searcher = new IndexSearcher(this.openDirectory(), true);
// 用多域查询解析器来创建一个查询器,
Query query = MultiFieldQueryParser.parse(Version.LUCENE_30,keyword, new String[] { FIELD_TITLE, FIELD_CONTENTS },
new BooleanClause.Occur[] {BooleanClause.Occur.SHOULD,BooleanClause.Occur.SHOULD }, this.getAnalyzer());
long begin = System.currentTimeMillis();
// 查询结集信息类
TopDocs ts = searcher.search(query, null, 100000);
// 获取命中的数量
lsr.setRecordCount(ts.totalHits);
// 用这个进行高亮显示，默认是<b>..</b>
SimpleHTMLFormatter simpleHTMLFormatter = new SimpleHTMLFormatter("<span style=color:red>", "</span>");
// 构造高亮:指定高亮的格式,指定查询评分
Highlighter highlighter = new Highlighter(simpleHTMLFormatter,new QueryScorer(query));highlighter.setTextFragmenter(new SimpleFragmenter(Integer.MAX_VALUE));
// 获取匹配到的结果集
ScoreDoc[] hits = ts.scoreDocs;
List<News> ais = new ArrayList<News>();
int pageCount = (lsr.getRecordCount() + pageSize - 1) / pageSize; // 总页数
int start = 0; // 要开始返回的文档编号
int end = 0; // 要结束返回的文档编号
if (pageCount > 0) {
start = (pageNo - 1) * pageSize;
end = start + pageSize;
if (pageNo == pageCount) { // 处理最后一页的结束文档的编号
end = start + (lsr.getRecordCount() % pageSize);
}
}
if (start < end) {
lsr.setStratNo(start + 1);
lsr.setEndNo(end);
}
for (int i = start; i < end; i++) { // 循环获取分页数据
// 通过内部编号从搜索器中得到对应的文档
Document doc = searcher.doc(hits[i].doc);
News news = new News();
news.setTitle(doc.getField(FIELD_TITLE).stringValue());
news.setContents(doc.getField(FIELD_CONTENTS).stringValue());
// 处理文件名称的高亮显示问题
String title = doc.getField(FIELD_TITLE).stringValue();
String title2 = highlighter.getBestFragment(this.getAnalyzer(),FIELD_TITLE, title);
if (title2 == null) {
news.setTitle(title);
} else {
news.setTitle(title2);
}
// 文件描述高亮显示
String contents1 = doc.getField(FIELD_CONTENTS).stringValue();
String contents2 = highlighter.getBestFragment(this.getAnalyzer(), FIELD_CONTENTS, contents1);
if (contents2 == null) {
news.setContents(contents1);
} else {
if (contents2.length() > 512) {
news.setContents(contents2.substring(0, 512) + "...");
} else {
news.setContents(contents2);
}
}
ais.add(news); // 把符合条件的数据添加到List
}
lsr.setTime((System.currentTimeMillis() - begin) / 1000.0); // 计算搜索耗时秒数
lsr.setDatas(ais); // 把查询到的数据添加到LuceneSearchResult
} catch (IOException e) {
e.printStackTrace();
} catch (ParseException e) {
e.printStackTrace();
} catch (InvalidTokenOffsetsException e) {
e.printStackTrace();
} finally {
if (searcher != null) {
try {
searcher.close(); // 关闭搜索器
} catch (Exception e) {
e.printStackTrace();
}
}
}
return lsr;
}
@Override
public void rebuildAllIndex() {
File file = new File(INDEX_DIR);
if (file.exists()) {
for (File subFile : file.listFiles()) {
subFile.delete();
}
} else {
file.mkdirs();
}
List<News> data = this.newsDao.findAll();
IndexWriter indexWriter = null;
try {
indexWriter = new IndexWriter(this.openDirectory(), getAnalyzer(),true, IndexWriter.MaxFieldLength.UNLIMITED);
// 设置打开使用复合文件
// indexWriter.setUseCompoundFile(true);
int size = data == null ? 0 : data.size();
for (int i = 0; i < size; i++) {
News news = data.get(i);
Document doc = createForumuploadDocument(news);
indexWriter.addDocument(doc);
if (i % 20 == 0) {
indexWriter.commit();
}
}
indexWriter.optimize(); // 对索引进行优化
} catch (CorruptIndexException e) {
e.printStackTrace();
} catch (LockObtainFailedException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (indexWriter != null) {
indexWriter.close();// 关闭IndexWriter,把内存中的数据写到文件
}
} catch (CorruptIndexException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
@Override
public void updateIndex(News news) {
this.deleteIndex(news.getId());
this.doIndexSingle(news);
}
public NewsDao getNewsDao() {
return newsDao;
}
public void setNewsDao(NewsDao newsDao) {
this.newsDao = newsDao;
}
}
对查询结果进行分页处理
package com.hkrt.domain;
import java.util.List;
public class LuceneSearchResult<T> {
private int pageNo = 1; //当前页
private int pageSize = 5; //每页显示记录数
private int recordCount; //总记录数
private double time; //耗时
private List<T> datas; //当前页的数据
private int stratNo; //开始记录数
private int endNo; //结束记录数
private String keyword; //关键字
public int getPageNo() {
return pageNo;
}
public void setPageNo(int pageNo) {
this.pageNo = pageNo;
}
public int getPageSize() {
return pageSize;
}
public void setPageSize(int pageSize) {
this.pageSize = pageSize;
}
public int getRecordCount() {
return recordCount;
}
public void setRecordCount(int recordCount) {
this.recordCount = recordCount;
}
public List<T> getDatas() {
return datas;
}
public void setDatas(List<T> datas) {
this.datas = datas;
}
public double getTime() {
return time;
}
public void setTime(double time) {
this.time = time;
}
public String getKeyword() {
return keyword;
}
public void setKeyword(String keyword) {
this.keyword = keyword;
}
public int getStratNo() {
return stratNo;
}
public void setStratNo(int stratNo) {
this.stratNo = stratNo;
}
public int getEndNo() {
return endNo;
}
public void setEndNo(int endNo) {
this.endNo = endNo;
}
}
代码已经实现对news 进行建立索引和对关键字进行索引lucene3.0.1 中需要的jar 包
建立索引：
搜索页面数据展示
<table width="100%" height="92" border="0" cellpadding="0" cellspacing="1">
<div class="title">搜索结果：搜索关键字【${lsr.keyword}】，共搜索到【${lsr.recordCount }】个文件，耗时：${lsr.time}秒，当前显示${lsr.stratNo}—${lsr.endNo}记录</div>
<c:forEach items="${request.lsr.datas}" var="news">
<tr>
<td height="30" colspan="6" align="left" bgcolor="#f2f2f2" class="left_txt">
${news.id}
</td>
<td height="30" colspan="6" align="left" bgcolor="#f2f2f2" class="left_txt">
${news.title}
</td>
<td height="30" colspan="6" align="left" bgcolor="#f2f2f2" class="left_txt">${news.contents}</td>
</tr>
</c:forEach>
</table> 最终搜索结果：
