Lucene入门例子(转裁）

http://sourceforge.net/projects/regain/files/ 

http://sourceforge.jp/projects/sfnet_regain/releases/?file_id=2419546 

http://code.google.com/p/paoding/downloads/list 







lucene3.0入门实例2009-12-07 21:33lucene3.0已于2009-11-25发布啦，但网上的入门实例都是针对lucene3.0以前的，相对于以前的版本，貌似改动不小。 

本人从零开始学习《lucene in action中文版》，并结合lucene3.0文档写了个入门实例，可供像我一样直接从lucene3.0开始学习的初学者参考！（变化大的地方用蓝字标出来了） 

入门实例： 

1.预处理：先把网上下载的一个《三国演义》电子书“三国演义.txt”（可用其他代替，呵呵）切割成多个小文件。 
/** 
* @author ht 
* 预处理 
* 
*/ 
public class FilePreprocess { 
public static void main(String[] arg){ 
String outputpath = "D:\\test\\small\\";//小文件存放路径 
String filename = "D:\\test\\三国演义.txt";//原文件存放路径 
if(!new File(outputpath).exists()){ 
new File(outputpath).mkdirs(); 
} 

splitToSmallFiles(new File(filename), outputpath); 
} 
/**大文件切割为小的 
* @param file 
* @param outputpath 
*/ 
public static void splitToSmallFiles(File file ,String outputpath){ 
int filePointer = 0; 
int MAX_SIZE = 10240;//小文件大小 
String filename = "output";//小文件的文件名前缀 

BufferedWriter writer = null; 
try { 
BufferedReader reader = new BufferedReader(new FileReader(file)); 
StringBuffer buffer = new StringBuffer(); 
String line = reader.readLine(); 
while(line != null){ 
buffer.append(line).append("\r\n"); 
if(buffer.toString().getBytes().length>=MAX_SIZE){ 
writer = new BufferedWriter(new FileWriter(outputpath+filename+filePointer+".txt")); 
writer.write(buffer.toString()); 
writer.close(); 
filePointer++; 
buffer=new StringBuffer(); 
} 
line = reader.readLine();                
} 
writer = new BufferedWriter(new FileWriter(outputpath+filename+filePointer+".txt")); 
writer.write(buffer.toString()); 
writer.close(); 
System.out.println("The file hava splited to small files !"); 
} catch (FileNotFoundException e) { 
System.out.println("file not found !"); 
e.printStackTrace(); 
} catch (IOException e) { 
e.printStackTrace(); 
}        
} 

2.用lucene3.0生成索引类:用lencene3.0对生成的多个小文件进行索引，中文分词用的是lucene3.0自带的StandardAnalyzer. 
/** 
* @author ht 
* 索引生成 
* 
*/ 
public class Indexer { 
private static String INDEX_DIR = "D:\\test\\index";//索引存放目录 
private static String DATA_DIR = "D:\\test\\small\\";//小文件存放的目录 

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

long start = new Date().getTime(); 
int numIndexed = index(new File(INDEX_DIR), new File(DATA_DIR));//调用index方法 
long end = new Date().getTime(); 
System.out.println("Indexing " + numIndexed + " files took " + (end - start) + " milliseconds"); 
} 

/**索引dataDir下的.txt文件，并储存在indexDir下，返回索引的文件数量 
* @param indexDir 
* @param dataDir 
* @return int 
* @throws IOException 
*/ 
public static int index(File indexDir, File dataDir) throws IOException { 

if (!dataDir.exists() || !dataDir.isDirectory()) { 
throw new IOException(dataDir + " does not exist or is not a directory"); 
} 

IndexWriter writer = new IndexWriter(FSDirectory.open(indexDir), new  StandardAnalyzer(Version.LUCENE_CURRENT), true,    
IndexWriter.MaxFieldLength.LIMITED); 

indexDirectory(writer, dataDir);//调用indexDirectory方法 
int numIndexed = writer.numDocs(); 
writer.optimize(); 
writer.close(); 
return numIndexed; 
} 

/**循环遍历目录下的所有.txt文件并进行索引 
* @param writer 
* @param dir 
* @throws IOException 
*/ 
private static void indexDirectory(IndexWriter writer, File dir) 
throws IOException { 

File[] files = dir.listFiles(); 

for (int i = 0; i < files.length; i++) { 
File f = files[i]; 
if (f.isDirectory()) { 
indexDirectory(writer, f);  // recurse 
} else if (f.getName().endsWith(".txt")) { 
indexFile(writer, f); 
} 
} 
} 

/**对单个txt文件进行索引 
* @param writer 
* @param f 
* @throws IOException 
*/ 
private static void indexFile(IndexWriter writer, File f) 
throws IOException { 

if (f.isHidden() || !f.exists() || !f.canRead()) { 
return; 
} 

System.out.println("Indexing " + f.getCanonicalPath()); 
Document doc = new Document(); 
doc.add(new Field("contents",new FileReader(f))); 
doc.add(new Field("filename",f.getCanonicalPath(),Field.Store.YES, Field.Index.ANALYZED)); 

writer.addDocument(doc); 
} 
} 


3.查询类：查询“玄德”！ 
/** 
* @author ht 
* 查询 
* 
*/ 
public class Searcher { 
private static String INDEX_DIR = "D:\\test\\index\\";//索引所在的路径 
private static String KEYWORD = "玄德";//关键词 
private static int TOP_NUM = 100;//显示前100条结果 

public static void main(String[] args) throws Exception { 
File indexDir = new File(INDEX_DIR); 
if (!indexDir.exists() || !indexDir.isDirectory()) { 
throw new Exception(indexDir + 
" does not exist or is not a directory."); 
} 
search(indexDir, KEYWORD);//调用search方法进行查询 
} 
/**查询 
* @param indexDir 
* @param q 
* @throws Exception 
*/ 
public static void search(File indexDir, String q) throws Exception { 
IndexSearcher is = new IndexSearcher(FSDirectory.open(indexDir),true);//read-only 
String field = "contents"; 

QueryParser parser = new QueryParser(Version.LUCENE_CURRENT, field, new  StandardAnalyzer(Version.LUCENE_CURRENT)); 
Query query = parser.parse(q); 

TopScoreDocCollector collector = TopScoreDocCollector.create(TOP_NUM , false); 

long start = new Date().getTime();// start time 

is.search(query, collector); 
ScoreDoc[] hits = collector.topDocs().scoreDocs; 

System.out.println(hits.length); 
for (int i = 0; i < hits.length; i++) { 
Document doc = is.doc(hits[i].doc);//new method is.doc() 
System.out.println(doc.getField("filename")+"   "+hits[i].toString()+"  "); 
} 
long end = new Date().getTime();//end time 

System.out.println("Found " + collector.getTotalHits() + 
" document(s) (in " + (end - start) + 
" milliseconds) that matched query '" + 
q + "':"); 
} 
}