Lucene搜索引擎例子demo

一.导入相应的jar包

KAnalyzer3.2.0Stable.jar

lucene-analyzers-3.0.1.jar

lucene-core-3.0.1.jar

lucene-highlighter-3.0.1.jar

lucene-memory-3.0.1.jar

二.写一个完整的demo

1.创建一个实体

DROP TABLE IF EXISTS `article`;

CREATE TABLE `article` (

  `id` int(11) NOT NULL AUTO_INCREMENT,

  `title` varchar(20) DEFAULT NULL,

  `content` varchar(5000) DEFAULT NULL,

  PRIMARY KEY (`id`)

) ENGINE=InnoDB DEFAULT CHARSET=utf8;

public class Article {
private int id;
private String title;
private String content;
get/set方法省略...
}

2.创建一个提供公共方法的类：

//提供封装分页数据的类：

@SuppressWarnings("rawtypes")
public class QueryResult {
private List list;
private int count;
get/set省略...
}

3.//提供创建索引，目录的类

public class LuceneUtils{
private static Directory directory;// 建立索引库存储目录
private static Analyzer analyzer;// 创建分词器
private static IndexWriter indexWriter; // 在程序启动是初始化,建立索引
private static IndexSearcher indexSearcher;// 查询
static {
try {
// 加载配置文件lucene.properties，该文件中是创建索引库的路径"path=D:\\IindexSearch
Properties prop = new Properties();
InputStream inStream = LuceneUtils.class.getClassLoader().getResourceAsStream("lucene.properties");
//InputStream inStream = ClassLoader.getSystemResourceAsStream("lucene.properties");
prop.load(inStream);
directory = FSDirectory.open(new File(prop.getProperty("path")));
analyzer = new StandardAnalyzer(Version.LUCENE_30);
// 在程序启动是初始化,建立索引
indexWriter = new IndexWriter(directory, analyzer, MaxFieldLength.LIMITED);
//程序退出时关闭资源
Runtime.getRuntime().addShutdownHook(new Thread(){
public void run(){
try {
indexWriter.close();
} catch (Exception e) {
e.printStackTrace();
} 
}
});
} catch (Exception e) {
e.printStackTrace();
}
}
public static Document objectToDocument(Object obj) {
Article article = (Article) obj;
// 将文档转为domcment
Document doc = new Document();
String idstr = NumericUtils.intToPrefixCoded(article.getId());
doc.add(new Field("id", idstr, Store.YES, Index.NOT_ANALYZED));
doc.add(new Field("title", article.getTitle(), Store.YES, Index.ANALYZED));
doc.add(new Field("content", article.getContent(), Store.YES, Index.ANALYZED));
return doc;
}
public static Object documentToObject(Document doc) {
Article article = new Article();
//将Document转为Article
//将字符串转化为数字
int id = NumericUtils.prefixCodedToInt(doc.get("id"));
article.setId(id);
article.setTitle(doc.get("title"));
article.setContent(doc.get("content"));
return article;
}
public static IndexWriter getIndexWriter() {
return indexWriter;
}
public static IndexSearcher getIndexSearch() {
// 执行查询
try {
indexSearcher = new IndexSearcher(directory);
} catch (Exception e) {
throw new RuntimeException(e);
}
return indexSearcher;
}
public static Directory getDirectory() {
return directory;
}
public static Analyzer getAnalyzer() {
return analyzer;
}
}

4.创建增删改查方法

public class IndexDao {
/**
* 
* @return
* @throws Exception
*/
public void save(Article article) {
try {
// 将Aritcle转为Documnet
Document doc = LuceneUtils.objectToDocument(article);
// 建立索引
IndexWriter indexWriter = LuceneUtils.getIndexWriter();
indexWriter.addDocument(doc);
indexWriter.commit();
} catch (Exception e) {
throw new RuntimeException(e);
}
}
/**
* 删除索引库 Term 表示制定列中包含的关键字
* 
* @return
* @throws Exception
*/
public void delete(Article article) {
String idStr = NumericUtils.intToPrefixCoded(article.getId());
Term term = new Term("id", idStr);
try {
// 建立索引
IndexWriter indexWriter = LuceneUtils.getIndexWriter();
indexWriter.deleteDocuments(term);// 删除指定Term总重的documnet数据
indexWriter.commit();
} catch (Exception e) {
throw new RuntimeException(e);
}
}
/**
* 修改索引库
* 
* @return
* @throws Exception
*/
public void update(Article article) {
// 创建Term
String idStr = NumericUtils.intToPrefixCoded(article.getId());
Term term = new Term("id", idStr);
// 准备document
Document doc = LuceneUtils.objectToDocument(article);
try {
// 建立索引
IndexWriter indexWriter = LuceneUtils.getIndexWriter();
indexWriter.updateDocument(term, doc);// 删除指定Term总重的documnet数据
indexWriter.commit();
// 先删除，在创建
// indexWriter.deleteDocuments(term);
// indexWriter.addDocument(doc);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
/**
* 查询索引库
* 
* @return
* @throws Exception
*/
public QueryResult query(String queryString, int first, int max) {
IndexSearcher indexSearcher = null;
try {
// MultiFieldQueryParser：表示可以根据多个字段查询
int totail = first + max;
// 1.把字符串转为Query对象
QueryParser parser = new MultiFieldQueryParser(Version.LUCENE_30, new String[] { "id", "title", "content" },
LuceneUtils.getAnalyzer());
Query query = parser.parse(queryString);
// 2.执行查询
indexSearcher = LuceneUtils.getIndexSearch();
// 指定排序条件
Sort sort = new Sort(new SortField("id", SortField.INT));// 按照id升序
TopDocs topDocs = indexSearcher.search(query, null, totail, sort);// 查询并返回最多的前n条数据
int count = topDocs.totalHits;// 总记录数
ScoreDoc[] scoreDoc = topDocs.scoreDocs;// 最多前n条结果数据
// 生成高亮显示器；设置前缀，后缀，摘要的大小
Formatter formatter = new SimpleHTMLFormatter("<font color='red'>", "</font>");
Scorer scorer = new QueryScorer(query);// 查询条件
Highlighter highlighter = new Highlighter(formatter, scorer);
highlighter.setTextFragmenter(new SimpleFragmenter(100));// 设置摘要的大小
// 3.取出数据
int endIndex = Math.min(totail, scoreDoc.length);
List<Article> list = new ArrayList<Article>();
for (int i = 0; i < endIndex; i++) {
// float score = scoreDoc[i].score;//平均得分
int docId = scoreDoc[i].doc;
Document doc = indexSearcher.doc(docId);
// 进行高亮操作,当没有找到关键词时，返回为null
String text = highlighter.getBestFragment(LuceneUtils.getAnalyzer(), "title", doc.get("title"));
if (text != null) {
doc.getField("title").setValue(text);
}
// 将Document转为Article
Article article = (Article) LuceneUtils.documentToObject(doc);
list.add(article);
}
QueryResult queryResult = new QueryResult(list, count);
return queryResult;
} catch (Exception e) {
throw new RuntimeException(e);
}
}

5.测试dao方法：

@Test
public void testSave() {
// 创建文档对象
Article article = new Article();
for (int i = 0; i < 20; i++) {
article.setId(i);
article.setTitle("Lucene搜索的方式");
article.setContent("全文检索是计算机程序通过扫描文章中的每一个词，对每一个词建立一个索引，指明该词在文章中出现的次数和位置。");
indexDao.save(article);
}
}
@Test
public void testDelete() {
Article article = new Article();
article.setId(1);
indexDao.delete(article);
}
@Test
public void testUpdate() {
// 创建文档对象
Article article = new Article();
article.setId(1);
article.setTitle("Lucene搜索的方式");
article.setContent("跟新索引库测试是否正确");
indexDao.update(article);
}
@Test
@SuppressWarnings("unchecked")
public void testQuery() {
String queryString = "Lucene";
QueryResult queryResult = indexDao.searchAndOrderBy(queryString, 0, 10);
System.out.println("count---------->" + queryResult.getCount());
List<Article> list = (List<Article>)queryResult.getList();
for(Article article:list){
System.err.println("list--------->" + article.toString());
}
}