lucene中FSDirectory、RAMDirectory的用法
package com.ljq.one; import java.io.BufferedReader; import java.io.File; import java.io.FileInputStream; import java.io.InputStreamReader; 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.NumberTools; import org.apache.lucene.document.Field.Index; import org.apache.lucene.document.Field.Store; import org.apache.lucene.index.IndexWriter; import org.apache.lucene.index.IndexWriter.MaxFieldLength; import org.apache.lucene.queryParser.MultiFieldQueryParser; import org.apache.lucene.queryParser.QueryParser; import org.apache.lucene.search.Filter; import org.apache.lucene.search.IndexSearcher; import org.apache.lucene.search.Query; import org.apache.lucene.search.ScoreDoc; import org.apache.lucene.search.TopDocs; import org.apache.lucene.store.Directory; import org.apache.lucene.store.FSDirectory; import org.apache.lucene.store.RAMDirectory; import org.junit.Test; public class DirectoryTest { // 数据源路径 String dspath = "E:/workspace/mylucene/lucenes/IndexWriter addDocument's a javadoc .txt"; //存放索引文件的位置,即索引库 String indexpath = "E:/workspace/mylucene/luceneIndex"; //分词器 Analyzer analyzer = new StandardAnalyzer(); /** * 创建索引,会抛异常,因为没对索引库进行保存 * * IndexWriter 用来操作(增、删、改)索引库的 */ @Test public void createIndex() throws Exception { //Directory dir=FSDirectory.getDirectory(indexpath); //内存存储:优点速度快,缺点程序退出数据就没了,所以记得程序退出时保存索引库,已FSDirectory结合使用 //由于此处只暂时保存在内存中,程序退出时没进行索引库保存,因此在搜索时程序会报错 Directory dir=new RAMDirectory(); File file = new File(dspath); //Document存放经过组织后的数据源,只有转换为Document对象才可以被索引和搜索到 Document doc = new Document(); //文件名称 doc.add(new Field("name", file.getName(), Store.YES, Index.ANALYZED)); //检索到的内容 doc.add(new Field("content", readFileContent(file), Store.YES, Index.ANALYZED)); //文件大小 doc.add(new Field("size", NumberTools.longToString(file.length()), Store.YES, Index.NOT_ANALYZED)); //检索到的文件位置 doc.add(new Field("path", file.getAbsolutePath(), Store.YES, Index.NOT_ANALYZED)); // 建立索引 //第一种方式 //IndexWriter indexWriter = new IndexWriter(indexpath, analyzer, MaxFieldLength.LIMITED); //第二种方式 IndexWriter indexWriter = new IndexWriter(dir, analyzer, MaxFieldLength.LIMITED); indexWriter.addDocument(doc); indexWriter.close(); } /** * 创建索引(推荐) * * IndexWriter 用来操作(增、删、改)索引库的 */ @Test public void createIndex2() throws Exception { Directory fsDir = FSDirectory.getDirectory(indexpath); //1、启动时读取 Directory ramDir = new RAMDirectory(fsDir); // 运行程序时操作ramDir IndexWriter ramIndexWriter = new IndexWriter(ramDir, analyzer, MaxFieldLength.LIMITED); //数据源 File file = new File(dspath); // 添加 Document Document doc = new Document(); //文件名称 doc.add(new Field("name", file.getName(), Store.YES, Index.ANALYZED)); //检索到的内容 doc.add(new Field("content", readFileContent(file), Store.YES, Index.ANALYZED)); //文件大小 doc.add(new Field("size", NumberTools.longToString(file.length()), Store.YES, Index.NOT_ANALYZED)); //检索到的文件位置 doc.add(new Field("path", file.getAbsolutePath(), Store.YES, Index.NOT_ANALYZED)); ramIndexWriter.addDocument(doc); ramIndexWriter.close(); //2、退出时保存 IndexWriter fsIndexWriter = new IndexWriter(fsDir, analyzer, true, MaxFieldLength.LIMITED); fsIndexWriter.addIndexesNoOptimize(new Directory[]{ramDir}); // 优化操作 fsIndexWriter.commit(); fsIndexWriter.optimize(); fsIndexWriter.close(); } /** * 优化操作 * * @throws Exception */ @Test public void createIndex3() throws Exception{ Directory fsDir = FSDirectory.getDirectory(indexpath); IndexWriter fsIndexWriter = new IndexWriter(fsDir, analyzer, MaxFieldLength.LIMITED); fsIndexWriter.optimize(); fsIndexWriter.close(); } /** * 搜索 * * IndexSearcher 用来在索引库中进行查询 */ @Test public void search() throws Exception { //请求字段 //String queryString = "document"; String queryString = "adddocument"; // 1,把要搜索的文本解析为 Query String[] fields = { "name", "content" }; QueryParser queryParser = new MultiFieldQueryParser(fields, analyzer); Query query = queryParser.parse(queryString); // 2,进行查询,从索引库中查找 IndexSearcher indexSearcher = new IndexSearcher(indexpath); Filter filter = null; TopDocs topDocs = indexSearcher.search(query, filter, 10000); System.out.println("总共有【" + topDocs.totalHits + "】条匹配结果"); // 3,打印结果 for (ScoreDoc scoreDoc : topDocs.scoreDocs) { // 文档内部编号 int index = scoreDoc.doc; // 根据编号取出相应的文档 Document doc = indexSearcher.doc(index); System.out.println("------------------------------"); System.out.println("name = " + doc.get("name")); System.out.println("content = " + doc.get("content")); System.out.println("size = " + NumberTools.stringToLong(doc.get("size"))); System.out.println("path = " + doc.get("path")); } } /** * 读取文件内容 */ public static String readFileContent(File file) { try { BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(file))); StringBuffer content = new StringBuffer(); for (String line = null; (line = reader.readLine()) != null;) { content.append(line).append("\n"); } reader.close(); return content.toString(); } catch (Exception e) { throw new RuntimeException(e); } } }