We Keep Coding

Lucene issues in indexing processus

I have a problem with lucene indexing, my documments conains TEXT and FIELD and DocNO. AND my queries containt Title and description. I have a Judgment of relevance. the problem is when i have calculating the MAP, it is very small (0.017). however my frieds have fiding a value of 0.13. I think that i have a problrm with IndexFiles class?? can you help me ? ^-^
public class IndexFiles {
public IndexFiles() {}
public static void main(String[] args) throws IOException, ParseException {
ReadDocuments t = new ReadDocuments();
List<DocumentsParser> docs = new ArrayList<>();
t.readXml(docs, "documents");
final String FIELD_PATH = "path";
final String FIELD_CONTENTS = "contents";
String indexPath = "index1";
Directory dir = FSDirectory.open(new File(indexPath));
Reader r=new FileReader(new File("stopwords.txt"));
StandardAnalyzer analyzer=new StandardAnalyzer(Version.LUCENE_40,r);
IndexWriterConfig iwc = new IndexWriterConfig(Version.LUCENE_40,analyzer);
/* use BM25 similarity*/
Similarity bm25similarity = new BM25Similarity();
iwc.setSimilarity(bm25similarity);
IndexWriter indexWriter = new IndexWriter(dir, iwc);
for (DocumentsParser doc : docs){
Document document = new Document();
document.add(new StringField("DocNo", doc.getDOCNO(), Field.Store.YES));
document.add(new TextField("TEXT", doc.getTEXT()+" "+doc.getHEAD(),Field.Store.YES));
indexWriter.addDocument(document); }
indexWriter.close();}}
/class SearchFiles/
public class SearchFiles {
public static void main(String[] args) throws Exception {
SearchFiles ch=new SearchFiles();
searchStemTfidfQLong();
}
SearchFiles() {}
public static void searchStemTfidfQLong() throws ParseException, IOException{
String index = "index1";
String field = "TEXT";
int hitsPerPage = 1000;
IndexReader reader = DirectoryReader.open(FSDirectory.open(new File(index)));
IndexSearcher searcher = new IndexSearcher(reader);
/* use BM25 similarity*/
Similarity bm25similarity = new BM25Similarity();
searcher.setSimilarity(bm25similarity);
Reader r=new FileReader(new File("stopwords.txt"));
StandardAnalyzer analyzer=new StandardAnalyzer(Version.LUCENE_40,r);
QueryParser parser = new QueryParser(Version.LUCENE_40,field,analyzer);
int i=0;
File file = new File("fichier.txt");
FileWriter writere=new FileWriter(file.getAbsoluteFile(), true);
for(Topic topic : Parser.getQuerysTopics(Parser.filename)){
/*query chort*/
String queryChort=topic.getTitle();
queryChort=queryChort.replaceAll("([<>\\(\\):/\\\\',\\s\"])", " ").trim();
i++;
//writere.write(queryChort+"\n");
Query query = parser.parse(queryChort);
System.out.println("Query number : "+(i));
searcher.search(query,1000);
doSearch(i, searcher, query, hitsPerPage);
}
reader.close();
writere.close();
}
public static void doSearch(int idReq, IndexSearcher searcher, Query query, int hitsPerPage) throws IOException {
TopDocs results = searcher.search(query, null, hitsPerPage);
System.out.println(query);
ScoreDoc[] hits = results.scoreDocs;
int numTotalHits = results.totalHits;
System.out.println(numTotalHits + " total matching documents");
int start = 1;
int end = Math.min(numTotalHits, hitsPerPage);
File file = new File("file.txt");
FileWriter writer=new FileWriter(file.getAbsoluteFile(), true);
File file1 = new File("fichier.txt");
FileWriter writere=new FileWriter(file1.getAbsoluteFile(), true);
for (int i = start; i < end; i++) {
Document doc = searcher.doc(hits[i].doc);
String DocNo = doc.get("DocNo");
writere.write(DocNo+"\n");
if (DocNo != null) {
writer.write(idReq+" 0 "+DocNo+" "+String.format("%.6f", new Double(hits[i].score))+" "+ i + " "+"ScoreID"+"\n");
} else {
System.out.println((i + 1) + ". " + "No DocNo for this document"); } }
writer.close();
writere.close();}}

How does regex query work on lucene?

I am trying to implement luecene search engine in my application.
I am using lucene 5.4.1
I have successfully implemented wildequeries and normal queries of lucene.
But my main focus is to search specific text in a text file with regex patterns.
Index Writer code:
public IndexWriter generateIndex(String docsPath) throws IOException {
String indexPath = System.getProperty("java.io.tmpdir") +File.separator+"indexDirectory";
if (indexPath == null) {
throw new IOException("System property 'java.io.tmpdir' does not specify a tmp dir");
}
File tmpDir = new File(indexPath);
if (!tmpDir.exists()) {
boolean created = tmpDir.mkdirs();
if (!created) {
throw new IOException("Unable to create tmp dir " + tmpDir);
}
}
boolean create = true;
final Path docDir = Paths.get(docsPath);
if (!Files.isReadable(docDir)) {
System.out.println("Document directory '" + docDir.toAbsolutePath()
+ "' does not exist or is not readable, please check the path");
System.exit(1);
}
Date start = new Date();
try {
System.out.println("Indexing to directory '" + indexPath + "'...");
Directory dir = FSDirectory.open(Paths.get(indexPath));
Analyzer analyzer = new StandardAnalyzer();
IndexWriterConfig iwc = new IndexWriterConfig(analyzer);
if (create) {
iwc.setOpenMode(OpenMode.CREATE);
} else {
iwc.setOpenMode(OpenMode.CREATE_OR_APPEND);
}
IndexWriter writer = new IndexWriter(dir, iwc);
indexDocs(writer, docDir);
setIndexWriter(writer);
Date end = new Date();
System.out.println(end.getTime() - start.getTime() + " total milliseconds");
writer.close();
} catch (IOException e) {
System.out.println(" caught a " + e.getClass() + "\n with message: " + e.getMessage());
}
return getIndexWriter();
}
static void indexDocs(final IndexWriter writer, Path path) throws IOException {
if (Files.isDirectory(path)) {
Files.walkFileTree(path, new SimpleFileVisitor<Path>() {
#Override
public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
try {
indexDoc(writer, file, attrs.lastModifiedTime().toMillis());
} catch (IOException ignore) {
// don't index files that can't be read.
}
return FileVisitResult.CONTINUE;
}
});
} else {
indexDoc(writer, path, Files.getLastModifiedTime(path).toMillis());
}
}
static void indexDoc(IndexWriter writer, Path file, long lastModified) throws IOException {
try (InputStream stream = Files.newInputStream(file)) {
Document doc = new Document();
Field pathField = new StringField("path", file.toString(), Field.Store.NO);
doc.add(pathField);
doc.add(new LongField("modified", lastModified, Field.Store.NO));
doc.add(new TextField("contents",
new BufferedReader(new InputStreamReader(stream, StandardCharsets.UTF_8))));
if (writer.getConfig().getOpenMode() == OpenMode.CREATE) {
System.out.println("adding " + file);
writer.addDocument(doc);
} else {
System.out.println("updating " + file);
writer.updateDocument(new Term("path", file.toString()), doc);
}
}
}
Index Searching Code:
public IndexReader searchExecutor(String index, String queryString, RegexCapabilities capability) throws Exception {
String field = "contents";
String queries = null;
boolean raw = false;
int hitsPerPage = Integer.MAX_VALUE;
IndexReader reader = DirectoryReader.open(FSDirectory.open(Paths.get(index)));
IndexSearcher searcher = new IndexSearcher(reader);
Analyzer analyzer = new StandardAnalyzer();
BufferedReader in = null;
Query q = new RegexpQuery(new Term("text", queryString));
q = q.rewrite(reader);
RegexQuery query = new RegexQuery(new Term("\\s*(FIND|find)"));
if (capability != null)
query.setRegexImplementation(capability);
System.out.println("Searching for: " + query.toString(field));
searcher.search(query, null, 1000);
doSearch(in, searcher, query, hitsPerPage, raw, queries == null && queryString == null);
//reader.close();
return reader;
}
public static void doSearch(BufferedReader in, IndexSearcher searcher, Query query, int hitsPerPage, boolean raw,
boolean interactive)
throws IOException {
TopDocs results = searcher.search(query, 5 * hitsPerPage);
ScoreDoc[] hits = results.scoreDocs;
//generateIndex.deleteDocuments(query);
//generateIndex.getDirectory();
// TermsEnum.totalTermFreq();
int numTotalHits = results.totalHits;
System.out.println(numTotalHits + " total matching documents");
int start = 0;
int end = Math.min(numTotalHits, hitsPerPage);
for (int i = start; i < end; i++) {
Document doc = searcher.doc(hits[i].doc);
String path = doc.get("path");
File file = new File(path);
if (path != null) {
System.out.println((i + 1) + ". " + path);
String title = doc.get("title");
if (title != null) {
System.out.println(" Title: " + doc.get("title"));
}
} else {
System.out.println((i + 1) + ". " + "No path for this document");
}
}
}
Please help.

Your question is about search with regular expressions in lucene.
You are using RegexQuery which is deprecated so try RegexpQuery
Your regEx-example starts with \s* but you do not use KeywordTokenizer. Most other tokenizer will remove (aka "split at") whitespace
Your regEx-example is not purely lower case. But standard analyzer contains LowerCaseFilter. Be aware: your regEx will go directly against the tokens of your index (not against the original text)
--> read Supported RegExp syntax and syntax in ES and TestRegexpRandom (test class) and play with https://github.com/DmitryKey/luke on your index.

Why indexer doesn't search Persian files?

I use lucene 3 for indexing some txt file like this.
public static void main(String[] args) throws Exception {
String indexDir = "file input";
String dataDir = "file input";
long start = System.currentTimeMillis();
indexer indexer = new indexer(indexDir);
int numIndexed, cnt;
try {
numIndexed = indexer.index(dataDir, new TextFilesFilter());
cnt = indexer.getHitCount("mycontents", "شهردار");
System.out.println("count of search in contents: " + cnt);
} finally {
indexer.close();
}
long end = System.currentTimeMillis();
System.out.println("Indexing " + numIndexed + " files took "
+ (end - start) + " milliseconds");
}
getHitCount function returns number of hits by an English word but by Persian word, it returns zero!
public int getHitCount(String fieldName, String searchString)
throws IOException, ParseException {
IndexSearcher searcher = new IndexSearcher(directory);
Term t = new Term(fieldName, searchString);
Query query = new TermQuery(t);
int hitCount = searcher.search(query, 1).totalHits;
searcher.close();
return hitCount;
}
How to set utf-8 in my project? I use netbeans and create a simple java project.
I just need a simple search in files!
It's my indexer class:
private IndexWriter writer;
private Directory directory;
public indexer(String indexDir) throws IOException {
directory = FSDirectory.open(new File(indexDir));
writer = new IndexWriter(directory,
new StandardAnalyzer(
Version.LUCENE_30),
true,
IndexWriter.MaxFieldLength.UNLIMITED);
}
public void close() throws IOException {
writer.close();
}
public int index(String dataDir, FileFilter filter)
throws Exception {
File[] files = new File(dataDir).listFiles();
for (File f : files) {
if (!f.isDirectory()
&& !f.isHidden()
&& f.exists()
&& f.canRead()
&& (filter == null || filter.accept(f))) {
indexFile(f);
}
}
return writer.numDocs();
}
private static class TextFilesFilter implements FileFilter {
public boolean accept(File path) {
return path.getName().toLowerCase()
.endsWith(".txt");
}
}
protected Document getDocument(File f) throws Exception {
Document doc = new Document();
doc.add(new Field("mycontents", new FileReader(f)));
doc.add(new Field("filename", f.getName(),
Field.Store.YES, Field.Index.NOT_ANALYZED));
doc.add(new Field("fullpath", f.getCanonicalPath(),
Field.Store.YES, Field.Index.NOT_ANALYZED));
return doc;
}
private void indexFile(File f) throws Exception {
System.out.println("Indexing " + f.getCanonicalPath());
Document doc = getDocument(f);
writer.addDocument(doc);
}

I suspect that the issue isn't Lucene's encoding, per se, but the FileReader. From the FileReader docs:
The constructors of this class assume that the default character encoding and the default byte-buffer size are appropriate.
The default character encoding is probably not appropriate, in this case.
Instead of:
doc.add(new Field("mycontents", new FileReader(f)));
try (assuming the file to be indexed is UTF-8 encoded):
doc.add(new Field("mycontents", new InputStreamReader(new FileInputStream(f), "UTF8")));

Getting TF-IDF values from index

The below code is for getting tf-idf value from indexes. But I get an error while running it, on the line with Correct_ME.
Using Lucene 4.8.
DocIndexing.java
public class DocIndexing {
private DocIndexing() {}
/** Index all text files under a directory.
* #param args
* #throws java.io.IOException */
public static void main(String[] args) throws IOException {
String usage = "java org.apache.lucene.demo.IndexFiles"
+ " [-index INDEX_PATH] [-docs DOCS_PATH] [-update]\n\n"
+ "This indexes the documents in DOCS_PATH, creating a Lucene index"
+ "in INDEX_PATH that can be searched with Searching";
String indexPath = "C:/Users/dell/Documents/NetBeansProjects/IndexingSearching/Index";
String docsPath = "C:/Users/dell/Documents/NetBeansProjects/IndexingSearching/ToBeIndexed";
boolean create = true;
for(int i=0;i<args.length;i++) {
if (null != args[i]) switch (args[i]) {
case "-index":
indexPath = args[i+1];
i++;
break;
case "-docs":
docsPath = args[i+1];
i++;
break;
case "-update":
create = false;
break;
}
}
if (docsPath == null) {
System.err.println("Usage: " + usage);
System.exit(1);
}
final File docDir = new File(docsPath);
if (!docDir.canRead() && !docDir.isDirectory() &&
!docDir.isHidden() &&
!docDir.exists()) {
System.out.println("Document directory '" +docDir.getAbsolutePath()+ "' does not exist or is not readable, please check the path");
System.exit(1);
}
Date start = new Date();
try {
System.out.println("Indexing to directory '" + indexPath + "'...");
Directory dir = FSDirectory.open(new File(indexPath));
Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_48);
//Filter filter = new PorterStemFilter();
IndexWriterConfig iwc = new IndexWriterConfig(Version.LUCENE_48, analyzer);
if (create) {
iwc.setOpenMode(OpenMode.CREATE);
} else {
// Add new documents to an existing index:
iwc.setOpenMode(OpenMode.CREATE_OR_APPEND);
}
try (
IndexWriter writer = new IndexWriter(dir, iwc)) {
indexDocs(writer, docDir);
}
Date end = new Date();
System.out.println(end.getTime() - start.getTime() + " total milliseconds");
} catch (IOException e) {
System.out.println(" caught a " + e.getClass() +
"\n with message: " + e.getMessage());
}
Tf_Idf tfidf = new Tf_Idf();
String field = null,term = null;
tfidf.scoreCalculator(field, term);
}
/*
* #param writer Writer to the index where the given file/dir info will be stored
* #param file The file to index, or the directory to recurse into to find files to index
* #throws IOException If there is a low-level I/O error
*/
static void indexDocs(IndexWriter writer, File file)
throws IOException {
// do not try to index files that cannot be read
if (file.canRead()) {
if (file.isDirectory()) {
String[] files = file.list();
// an IO error could occur
if (files != null) {
for (int i = 0; i < files.length; i++) {
indexDocs(writer, new File(file, files[i]));
}
}
} else {
FileInputStream fis;
try {
fis = new FileInputStream(file);
} catch (FileNotFoundException fnfe) {
return;
}
try {
// make a new, empty document
Document doc = new Document();
// Field termV = new LongField("termVector", file.g)
Field pathField = new StringField("path", file.getPath(), Field.Store.YES);
doc.add(pathField);
Field modifiedField = new LongField("modified", file.lastModified(), Field.Store.NO);
doc.add(modifiedField);
Field titleField = new TextField("title", file.getName(), Field.Store.YES);
doc.add(titleField);
Field contentsField = new TextField("contents", new BufferedReader(new InputStreamReader(fis, StandardCharsets.UTF_8)));
doc.add(contentsField);
//contentsField.setBoost((float)0.5);
//titleField.setBoost((float)2.5);
/* doc.add(new LongField("modified", file.lastModified(), Field.Store.NO));
doc.add(new TextField("title", file.getName(), Field.Store.YES));
doc.add(new TextField("contents", new BufferedReader(new InputStreamReader(fis, StandardCharsets.UTF_8))));
*/
// StringField..setBoost(1.2F);
if (writer.getConfig().getOpenMode() == OpenMode.CREATE) {
// New index, so we just add the document (no old document can be there):
System.out.println("adding " + file);
writer.addDocument(doc);
} else {
// Existing index (an old copy of this document may have been indexed) so
// we use updateDocument instead to replace the old one matching the exact
// path, if present:
System.out.println("updating " + file);
writer.updateDocument(new Term("path", file.getPath()), doc);
}
} finally {
fis.close();
}
}
}
}
}
Tf-idf.java
public class Tf_Idf {
static float tf = 1;
static float idf = 0;
private float tfidf_score;
static float [] tfidf = null;
IndexReader indexReader;
public Tf_Idf() throws IOException {
this.indexReader = DirectoryReader.open(FSDirectory.open(new File("C:/Users/dell/Documents/NetBeansProjects/IndexingSearching/Index")));
}
public void scoreCalculator (String field, String term) throws IOException
{
TFIDFSimilarity tfidfSIM = new DefaultSimilarity();
Bits liveDocs = MultiFields.getLiveDocs(indexReader);
TermsEnum termEnum = MultiFields.getTerms(indexReader, field).iterator(null);
BytesRef bytesRef=null;
while ((bytesRef = termEnum.next()) != null) {
if(bytesRef.utf8ToString().trim().equals(term.trim())) {
if(termEnum.seekExact(bytesRef)) {
idf = tfidfSIM.idf(termEnum.docFreq(), indexReader.numDocs());
DocsEnum docsEnum = termEnum.docs(liveDocs, null);
if(docsEnum != null) {
int doc=0;
while((doc = docsEnum.nextDoc()) != DocIdSetIterator.NO_MORE_DOCS) {
tf = tfidfSIM.tf(docsEnum.freq());
tfidf_score = tf * idf ;
System.out.println(" -tfidf_score-" + tfidf_score);
}
}
}
}
}
}
}

It's obvious that you pass to MultiFields method a null IndexReader
IndexReader reader = null;
tfidf.scoreCalculator( reader, field,term);
You need to write something like this:
IndexReader reader = DirectoryReader.open(FSDirectory.open(new File(PATH_TO_LUCENE_INDEX)));
tfidf.scoreCalculator( reader, field,term);
You need to repalce PATH_TO_LUCENE_INDEX with real path, of course.
Another problem, that I see - you open IndexReader in Tf_Idf, but don't use it anywhere, may be it's a good idea to remove it or use it, inside of scoreCalculator method, e.g.
tfidf.scoreCalculator(field,term);
but in method use field of this class, - this.indexReader instead of just indexReader that you try to pass inside method scoreCalculator
UPD
public Tf_Idf() throws IOException {
this.reader = DirectoryReader.open(FSDirectory.open(new File("Index")));
}
In this code, you need to replace "Index" with real path to your Lucene index, e.g. - /home/user/index or C://index or wherever you have it.

Deleting Multiple Files Java (Android)

I'm new to programming Android, and I want to delete Files on the sd-card. This is my current (working) code...
File appvc = new File(Environment.getExternalStorageDirectory()
.getAbsolutePath(), "ApplifierVideoCache");
if (appvc.isDirectory()) {
String[] children = appvc.list();
for (int i = 0; i < children.length; i++) {
new File(appvc, children[i]).delete();
}
}
Now I want to delete multiple files, but dont want to mention each file with that big block. Am I able to combine all files in one variable? Thanks ;)

Make a recursive method:
/*
* NOTE: coded so as to work around File's misbehaviour with regards to .delete(),
* which does not throw an exception if it fails -- or why you should use Java 7's Files
*/
public void doDelete(final File base)
throws IOException
{
if (base.isDirectory()) {
for (final File entry: base.listFiles())
doDelete(entry);
return;
}
if (!file.delete())
throw new IOException ("Failed to delete " + file + '!');
}

Another possibility would be using the Apache commons-io library and calling
if (file.isDirectory())
FileUtils.deleteDirectory(File directory);
else {
if(!file.delete())
throw new IOException("Failed to delete " + file);
}

You should make a method out of this chunk of code, pass file name and call it whenever you like:
public void DeleteFile(String fileName) {
File appvc = new File(Environment.getExternalStorageDirectory()
.getAbsolutePath(), fileName);
if (appvc.isDirectory()) {
String[] children = appvc.list();
for (int i = 0; i < children.length; i++) {
new File(appvc, children[i]).delete();
}
}
}

File dir = new File(android.os.Environment.getExternalStorageDirectory(),"ApplifierVideoCache");
Then call
deletedir(dir);
public void deletedir(File dir) {
File listFile[] = dir.listFiles();
if (listFile != null) {
for (int i = 0; i < listFile.length; i++) {
listFile[i].delete();
}
}
}
or if your folder as sub folders then
public void walkdir(File dir) {
File listFile[] = dir.listFiles();
if (listFile != null) {
for (int i = 0; i < listFile.length; i++)
{
if (listFile[i].isDirectory())
{
walkdir(listFile[i]);
} else
{
listFile[i].delete();
}
}
}

For kotlin
Create a array of path list
val paths: MutableList<String> = ArrayList()
paths.add("Yor path")
paths.add("Yor path")
.
.
delete file for each path
try{
paths.forEach{
val file = File(it)
if(file.exists(){
file.delete()
}
}
}catch(e:IOException){
}