[编程实例] Lucene Demo 小实例

首先是文件索引：

先用爬虫爬几个页面放在特定目录下，我挑取了 google,baidu,yahoo 的代码来做例子：）

Writer.java


public class Writer




...{


public static void main(String[] args) throws Exception




...{


//fileDir is the directory that contains the text files to be indexed


File fileDir = new File("D:/work/source");




//indexDir is the directory that hosts Lucene's index files


File indexDir = new File("D:/work/index");


Analyzer luceneAnalyzer = new StandardAnalyzer();


IndexWriter indexWriter = new IndexWriter(indexDir,luceneAnalyzer,true);


File[] textFiles = fileDir.listFiles();


System.out.println("Total indexed "" + textFiles.length + "" files ! ");





long startTime = new Date().getTime();




//Add documents to the index




for(int i = 0; i < textFiles.length; i++)...{




if (textFiles[i].isFile() && textFiles[i].getName().endsWith(".htm")) ...{


System.out.println("File " + textFiles[i].getCanonicalPath() + " is being indexed");


Reader textReader = new FileReader(textFiles[i]);


Document document = new Document();


document.add(new Field("content",textReader));


document.add(new Field("path",textFiles[i].getPath(),Field.Store.YES,Field.Index.TOKENIZED));


indexWriter.addDocument(document);


}


}




indexWriter.optimize();


indexWriter.close();


long endTime = new Date().getTime();




System.out.println(" It took " + (endTime - startTime)


+ " milliseconds to create an index for the files in the directory "


+ fileDir.getPath());


}


}

Searcher.java


public class Searcher




...{


public static final String path = "D:/work/index";





public static void main(String[] args) throws Exception




...{


IndexSearcher searcher = new IndexSearcher(path);


Hits hits = null;


Query query = null;


QueryParser qp = new QueryParser("content", new StandardAnalyzer());





String searchText = "yahoo job google baidu";





query = qp.parse(searchText);


hits = searcher.search(query);


System.out.println("Search "" + searchText + "" total " + hits.length() + " result ! ");




for (Iterator it = hits.iterator(); it.hasNext(); ) ...{


Hit hit = (Hit) it.next();


System.out.println(hit.getDocument().getField("path").stringValue());


}


}


}


以下是一个 DB 索引的例子，大家可以看看：

数据库环境：SQL Server 2005
数据库名称：mydb
数据库表：users
表结构：

Table users
PK	id
	name
	pass
	updatetime

DBIndexer.java


public class DBIndexer




...{


private String driver="com.microsoft.sqlserver.jdbc.SQLServerDriver";


private String url="jdbc:sqlserver://localhost:1433;databaseName=mydb;";


private String user="sa";


private String pass="123456";


private Connection conn=null;


private Statement st=null;


private ResultSet rs=null;


private String indexUrl="D:/work/index/mydb";






private ResultSet getResult() throws Exception...{




try ...{


Class.forName(driver);


conn = DriverManager.getConnection(url, user, pass);


String sql = "select * from users";


st = conn.createStatement();


rs = st.executeQuery(sql);


// while (rs.next()) {


// System.out.print(rs.getInt("id") + " ");


// System.out.print(rs.getString("name") + " ");


// System.out.print(rs.getString("pass") + " ");


// System.out.print(rs.getDate("updatetime") + " ");


// }


}




catch (Exception e) ...{


e.printStackTrace();


}


return rs;


}






private void executeIndex(ResultSet rs, IndexWriter indexWriter) throws Exception...{


int i=0;




while(rs.next())...{


int id = rs.getInt("id");


String name = rs.getString("name");


String time = rs.getString("updatetime");







Document doc = new Document();




Field idField=new Field("id", Integer.toString(id), Field.Store.YES, Field.Index.NO, Field.TermVector.NO);


Field nameField=new Field("name", name, Field.Store.YES, Field.Index.TOKENIZED, Field.TermVector.YES);


Field timeField=new Field("time", time, Field.Store.YES, Field.Index.TOKENIZED, Field.TermVector.YES);




doc.add(idField);


doc.add(nameField);


doc.add(timeField);




indexWriter.addDocument(doc);




i++;


}


this.close();


System.out.println("共处理记录："+i);


}






private void close() throws Exception...{


this.rs.close();


this.st.close();


this.conn.close();


}






public void createIndex() throws Exception...{


// get data ResultSet


ResultSet rs=this.getResult();




// Analyzer chineseAnalyzer = new ChineseAnalyzer();


Analyzer chineseAnalyzer = new StandardAnalyzer();


IndexWriter indexWriter = new IndexWriter(this.indexUrl, chineseAnalyzer, true);


indexWriter.setMergeFactor(100);


indexWriter.setMaxBufferedDocs(100);




java.util.Date startDate=new java.util.Date();




System.out.println("开始索引时间：" + startDate);




executeIndex(rs, indexWriter);




indexWriter.optimize();




indexWriter.close();




java.util.Date endDate=new java.util.Date();




System.out.println("索引结束时间：" + endDate);


System.out.println("共花费：" + (endDate.getTime()-startDate.getTime()) + "ms");


}







public static void main (String args[]) throws Exception ...{


DBIndexer oIndexer = new DBIndexer();


oIndexer.createIndex();


}


}

DBSearcher.java




public class DBSearcher ...{





private static final String indexUrl="D:/work/index/mydb";






public static void main(String[] args) throws Exception ...{







/**//*建立索引代码，查找时注释*/


//Index index=new Index();


//index.createIndex();




File indexDir = new File(indexUrl);


FSDirectory fdir = FSDirectory.getDirectory(indexDir);




IndexSearcher searcher = new IndexSearcher(fdir);




//对中文建立解析（必须）


// Analyzer chineseAnalyzer = new ChineseAnalyzer();


Analyzer chineseAnalyzer = new StandardAnalyzer();


QueryParser parser = new QueryParser("name", chineseAnalyzer);


Query query = parser.parse("石头");




Date startDate = new Date();


System.out.println("检索开始时间："+startDate);




Hits result = searcher.search(query);






for(int i=0; i<result.length(); i++)...{


Document doc = result.doc(i);


System.out.println("用户ID：" + doc.get("id") + " 更新时间：" + doc.get("time"));


}




Date endDate=new Date();




System.out.println("共有记录：" + result.length());


System.out.println("共花费：" + (endDate.getTime()-startDate.getTime()) + "ms");


}




}