indexmanager.java

基于lucene的搜索引

package sample.dw.paper.lucene.index;

import java.io.File;
import java.io.IOException;
import java.io.Reader;

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.IndexWriter;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;

import sample.dw.paper.lucene.util.HTMLDocParser;

/**
 * This class is used to create index for html files
 *
 */
public class IndexManager {
	
	//the directory that stores html files
    private final String dataDir  = "c:\\dataDir";
    
    //the directory that is used to store lucene index
    private final String indexDir = "c:\\indexDir";
    
    /**
     * create index
     */
    public boolean createIndex() throws IOException{
    	if(true == ifIndexExist()){
    	    return true;	
    	}
    	File dir = new File(dataDir);
    	if(!dir.exists()){
    		return false;
    	}
    	File[] htmls = dir.listFiles();
    	Directory fsDirectory = FSDirectory.getDirectory(indexDir, true);
    	Analyzer  analyzer    = new StandardAnalyzer();
    	IndexWriter indexWriter = new IndexWriter(fsDirectory, analyzer, true);
    	for(int i = 0; i < htmls.length; i++){
    		String htmlPath = htmls[i].getAbsolutePath();
   
    		if(htmlPath.endsWith(".html") || htmlPath.endsWith(".htm")|| htmlPath.endsWith(".txt")){
        		addDocument(htmlPath, indexWriter);
    		}
    	}
    	indexWriter.optimize();
    	indexWriter.close();
    	return true;
    	
    }
    
    /**
     * Add one document to the lucene index
     */
    public void addDocument(String htmlPath, IndexWriter indexWriter){
    	HTMLDocParser htmlParser = new HTMLDocParser(htmlPath);
    	String path    = htmlParser.getPath();
    	String title   = htmlParser.getTitle();
    	Reader content = htmlParser.getContent();
    	
    	Document document = new Document();
    	document.add(new Field("path",path,Field.Store.YES,Field.Index.NO));
    	document.add(new Field("title",title,Field.Store.YES,Field.Index.TOKENIZED));
    	document.add(new Field("content",content));
    	try {
			indexWriter.addDocument(document);
		} catch (IOException e) {
			e.printStackTrace();
		}
    }
    
    /**
     * judge if the index is already exist
     */
    public boolean ifIndexExist(){
        File directory = new File(indexDir);
        if(0 < directory.listFiles().length){
        	return true;
        }else{
        	return false;
        }
    }
    
    public String getDataDir(){
    	return this.dataDir;
    }
    
    public String getIndexDir(){
    	return this.indexDir;
    }
        
}