lucene的普通搜索(二)

首先得到索引:

package com.wp.util;

import java.io.File;
import java.io.FileReader;
import java.nio.file.Paths;

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.document.TextField;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;

public class Indexer {

    private IndexWriter writer; // 写索引实例

    /**
     * 构造方法 实例化IndexWriter
     * 
     * @param indexDir
     * @throws Exception
     */
    public Indexer(String indexDir) throws Exception {
        Directory dir = FSDirectory.open(Paths.get(indexDir));// 根据路径获取存储索引的目录
        Analyzer analyzer = new StandardAnalyzer(); // 这里用了多态，StandardAnalyzer是一个标准分词器,
        IndexWriterConfig iwc = new IndexWriterConfig(analyzer);//将分词器加入到索引中
        writer = new IndexWriter(dir, iwc);
    }

    /**
     * 关闭写索引
     * 
     * @throws Exception
     */
    public void close() throws Exception {
        writer.close();
    }

    /**
     * 索引指定目录的所有文件
     * 
     * @param dataDir
     * @throws Exception
     */
    public int index(String dataDir) throws Exception {
        File[] files = new File(dataDir).listFiles();//得到目录下的所有文件
        for (File f : files) {
            indexFile(f);
        }
        return writer.numDocs();
    }

    /**
     * 索引指定文件
     * 
     * @param f
     */
    private void indexFile(File f) throws Exception {
        // 关于f.getCanonicalPath()查看http://www.blogjava.net/dreamstone/archive/2007/08/08/134968.html
        System.out.println("索引文件：" + f.getCanonicalPath());//得到绝对路径
        Document doc = getDocument(f);
        writer.addDocument(doc);
    }

    /**
     * 获取文档，文档里再设置每个字段
     * 
     * @param f
     */
    private Document getDocument(File f) throws Exception {
        Document doc = new Document();//创建文档
        doc.add(new TextField("contents", new FileReader(f)));//以文件流的形式读取文件内容
        doc.add(new TextField("fileName", f.getName(), Field.Store.YES));//Field.Store.YES表示将属性存入内存中
        doc.add(new TextField("fullPath", f.getCanonicalPath(),Field.Store.YES));//存入内存中
        return doc;
    }

    public static void main(String[] args) {
        String indexDir = "D:\lucene\luceneIndex";
        String dataDir = "D:\lucene\data";
        Indexer indexer = null;
        int numIndexed = 0;
        long start = System.currentTimeMillis();
        try {
            indexer = new Indexer(indexDir);//创建索引
            numIndexed = indexer.index(dataDir);//索引指定目录的所有文件
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                indexer.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        long end = System.currentTimeMillis();
        System.out.println("索引：" + numIndexed + " 个文件 花费了" + (end - start)
                + " 毫秒");
    }
}

 增加的知识：

getPath():

返回的是定义时的路径，可能是相对路径，也可能是绝对路径，这个取决于定义时用的是相对路径还是绝对路径。如果定义时用的是绝对路径，那么使用getPath()返回的结果跟用getAbsolutePath()返回的结果一样

getAbsolutePath():

返回的是定义时的路径对应的相对路径，但不会处理“.”和“..”的情况

getCanonicalPath():

返回的是规范化的绝对路径，相当于将getAbsolutePath()中的“.”和“..”解析成对应的正确的路径

搜索：

package com.wp.util;

import java.nio.file.Paths;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.Term;
import org.apache.lucene.queryparser.classic.QueryParser;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

public class SearchTest {

    private Directory dir;
    private IndexReader reader;
    private IndexSearcher is;

    @Before
    public void setUp() throws Exception {
        dir = FSDirectory.open(Paths.get("D:\lucene\luceneIndex"));// 得到存储索引的目录
        reader = DirectoryReader.open(dir);// 读取索引
        is = new IndexSearcher(reader);// //创建索引搜索
    }

    @After
    public void tearDown() throws Exception {
        reader.close();
    }

    /**
     * 对特定项搜索(只能是指定的字符串，而不是其中的字母)
     * 
     * @throws Exception
     */
    @Test
    public void testTermQuery() throws Exception {
        String searchField = "contents";
        String q = "particular";
        Term t = new Term(searchField, q);// 查询contents中的particular字符
        Query query = new TermQuery(t);// 对特定字符查询
        TopDocs hits = is.search(query, 10);// 得到查询的最前面10条数据
        System.out.println("匹配 '" + q + "'，总共查询到" + hits.totalHits + "个文档");
        for (ScoreDoc scoreDoc : hits.scoreDocs) {
            Document doc = is.doc(scoreDoc.doc);// 得到查询到的得分文档个数
            System.out.println(doc.get("fullPath"));
        }
    }

    /**
     * 解析查询表达式
     * 
     * @throws Exception
     */
    @Test
    public void testQueryParser() throws Exception {
        Analyzer analyzer = new StandardAnalyzer(); // 标准分词器
        String searchField = "contents";
        // String q = "particular AND SA";//表示查询都： 注意AND要大写
        // String q = "particular or a";// 表示查询或者
        String q = "particular~";// ~符号表示查询相近的
        QueryParser parser = new QueryParser(searchField, analyzer);
        Query query = parser.parse(q);// 进行解析
        TopDocs hits = is.search(query, 100);
        System.out.println("匹配 " + q + "查询到" + hits.totalHits + "个记录");
        for (ScoreDoc scoreDoc : hits.scoreDocs) {
            Document doc = is.doc(scoreDoc.doc);
            System.out.println(doc.get("fullPath"));
        }
    }
}