lucene5.0建立索引并进行查找

说白了就是两个函数一个建立索引（写），另一个来查找（读），所以涉及到java IO的一些知识。

import java.io.*; import java.nio.file.Paths;import java.util.Date; 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.Field.Store;import org.apache.lucene.document.LongField;import org.apache.lucene.document.StringField;import org.apache.lucene.document.TextField;import org.apache.lucene.index.*; import org.apache.lucene.store.Directory;import org.apache.lucene.store.FSDirectory;/** * This class demonstrate the process of creating index with Lucene * for text files */ public class TxtFileIndexer {      public static void main(String[] args) throws Exception{      //indexDir is the directory that hosts Lucene's index files      Directory indexDir = FSDirectory.open(Paths.get("G:\\luceneout"));     //dataDir is the directory that hosts the text files that to be indexed      File   dataDir  = new File("G:\\downloads\\LJParser_release\\LJParser_Packet\\训练分类用文本\\交通");      Analyzer luceneAnalyzer = new StandardAnalyzer(); //新建一个分词器实例     IndexWriterConfig config = new IndexWriterConfig(luceneAnalyzer);     File[] dataFiles  = dataDir.listFiles(); //所有训练样本文件     IndexWriter indexWriter = new IndexWriter(indexDir,config);//构造一个索引写入器      long startTime = new Date().getTime();      for(int i = 0; i < dataFiles.length; i++){           if(dataFiles[i].isFile() && dataFiles[i].getName().endsWith(".txt")){               System.out.println("Indexing file " + dataFiles[i].getCanonicalPath()); //返回绝对路径               Document document = new Document();//每一个文件都变成一个document对象                Reader txtReader = new FileReader(dataFiles[i]);                Field field1 = new StringField("path",dataFiles[i].getPath(),Store.YES);               Field field2 = new TextField("content",txtReader);               Field field3 = new LongField("fileSize", dataFiles[i].length(), Store.YES);                Field field4 = new TextField("filename",dataFiles[i].getName(),Store.YES);               document.add(field1);               document.add(field2);               document.add(field3);               document.add(field4);               indexWriter.addDocument(document); //写进一个索引          }      }      //indexWriter.optimize();      indexWriter.close();      long endTime = new Date().getTime();              System.out.println("It takes " + (endTime - startTime)          + " milliseconds to create index for the files in directory "         + dataDir.getPath());             } }

读取索引并查找

import java.io.File; import java.nio.file.Paths;import org.apache.lucene.analysis.standard.StandardAnalyzer;import org.apache.lucene.document.Document; import org.apache.lucene.index.DirectoryReader;  import org.apache.lucene.queryparser.classic.QueryParser;import org.apache.lucene.search.*; import org.apache.lucene.store.*; /**  * This class is used to demonstrate the  * process of searching on an existing  * Lucene index  *  */  public class TxtFileSearcher {  public static void main(String[] args) throws Exception{  //存储了索引文件 Directory indexDir = FSDirectory.open(Paths.get("G:\\luceneout")); //读取器读取索引文件 DirectoryReader ireader = DirectoryReader.open(indexDir); //查找 IndexSearcher searcher = new IndexSearcher(ireader); //目的查找字符串 String queryStr = "大数据挖掘"; //构造一个词法分析器，并将查询结果返回到一个队列 QueryParser parser = new QueryParser("content",new StandardAnalyzer()); Query query = parser.parse(queryStr); TopDocs docs = searcher.search(query, 100); System.out.print("一共搜索到结果："+docs.totalHits+"条"); //输出查询结果信息 for(ScoreDoc scoreDoc:docs.scoreDocs){ System.out.print("序号为:"+scoreDoc.doc); System.out.print("评分为:"+scoreDoc.score); Document document = searcher.doc(scoreDoc.doc); System.out.print("路径为:"+document.get("path")); System.out.print("内容为"+document.get("content")); System.out.print("文件大小为"+document.get("fileSize")); System.out.print("文件名为"+document.get("filename")); System.out.println(); }  }  }

运行结果

下面是文件目录

两个函数都需要用到分词器，前者是为了配置写入，后者则是为了配置词法分析器来查找