我正在尝试从Lucene获取术语文档矩阵。似乎大多数SO问题都针对具有不同类的过时API。我尝试将这两个问题的见解相结合,以从每个文档中获取术语向量:
Term Vector Frequency in Lucene 4.0
Is it possible to iterate through documents stored in Lucene Index?
相关代码,但在当前API中无法识别DocEnum
。如何获得每个文档的术语向量或所有术语的计数?
IndexReader reader = DirectoryReader.open(index);
for (int i = 0; i < reader.maxDoc(); i++) {
Document doc = reader.document(i);
Terms terms = reader.getTermVector(i, "country_text");
if (terms != null && terms.size() > 0) {
// access the terms for this field
TermsEnum termsEnum = terms.iterator();
BytesRef term = null;
// explore the terms for this field
while ((term = termsEnum.next()) != null) {
// enumerate through documents, in this case only one
DocsEnum docsEnum = termsEnum.docs(null, null);
int docIdEnum;
while ((docIdEnum = docsEnum.nextDoc()) != DocIdSetIterator.NO_MORE_DOCS) {
// get the term frequency in the document
System.out.println(term.utf8ToString()+ " " + docIdEnum + " " + docsEnum.freq());
}
}
}
}
完整代码:
import java.io.*;
import java.util.Iterator;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.StringField;
import org.apache.lucene.document.TextField;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.index.Term;
import org.apache.lucene.index.Terms;
import org.apache.lucene.index.TermsEnum;
import org.apache.lucene.queryparser.classic.ParseException;
import org.apache.lucene.queryparser.classic.QueryParser;
import org.apache.lucene.search.BooleanClause;
import org.apache.lucene.search.BooleanQuery;
import org.apache.lucene.search.FuzzyQuery;
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.RAMDirectory;
import org.apache.lucene.util.BytesRef;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.JSONValue;
import org.json.simple.parser.JSONParser;
public class LuceneIndex {
public static void main(String[] args) throws IOException, ParseException {
String jsonFilePath = "wiki_data.json";
JSONParser parser = new JSONParser();
// Specify the analyzer for tokenizing text.
StandardAnalyzer analyzer = new StandardAnalyzer();
// create the index
Directory index = new RAMDirectory();
IndexWriterConfig config = new IndexWriterConfig(analyzer);
IndexWriter w = new IndexWriter(index, config);
try {
JSONArray a = (JSONArray) parser.parse(new FileReader(jsonFilePath));
for (Object o : a) {
JSONObject country = (JSONObject) o;
String countryName = (String) country.get("country_name");
String cityName = (String) country.get("city_name");
String countryText = (String) country.get("country_text");
String cityText = (String) country.get("city_text");
System.out.println(cityName);
addDoc(w, countryName, cityName, countryText, cityText);
}
w.close();
IndexReader reader = DirectoryReader.open(index);
for (int i = 0; i < reader.maxDoc(); i++) {
Document doc = reader.document(i);
Terms terms = reader.getTermVector(i, "country_text");
if (terms != null && terms.size() > 0) {
// access the terms for this field
TermsEnum termsEnum = terms.iterator();
BytesRef term = null;
// explore the terms for this field
while ((term = termsEnum.next()) != null) {
// enumerate through documents, in this case only one
DocsEnum docsEnum = termsEnum.docs(null, null);
int docIdEnum;
while ((docIdEnum = docsEnum.nextDoc()) != DocIdSetIterator.NO_MORE_DOCS) {
// get the term frequency in the document
System.out.println(term.utf8ToString()+ " " + docIdEnum + " " + docsEnum.freq());
}
}
}
}
// reader can be closed when there
// is no need to access the documents any more.
reader.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (org.json.simple.parser.ParseException e) {
e.printStackTrace();
}
}
private static void addDoc(IndexWriter w, String countryName, String cityName,
String countryText, String cityText) throws IOException {
Document doc = new Document();
doc.add(new StringField("country_name", countryName, Field.Store.YES));
doc.add(new StringField("city_name", cityName, Field.Store.YES));
doc.add(new TextField("country_text", countryText, Field.Store.YES));
doc.add(new TextField("city_text", cityText, Field.Store.YES));
w.addDocument(doc);
}
}
最佳答案
根据此question,您不应将TextField用于词频。因为它不计算。
使用“字段”。
关于java - Lucene中的术语文档矩阵,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/47321816/