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。
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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());
}
}
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
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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();
}
}
}
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