import java.io.IOException;

import javax.servlet.*;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.File;

import java.io.FileReader;

import java.util.ArrayList;

import java.util.List;

import org.apache.lucene.analysis.Analyzer;

import org.apache.lucene.analysis.util.WordlistLoader;

import org.apache.lucene.document.Document;

import org.apache.lucene.index.*;

import org.apache.lucene.queryparser.classic.MultiFieldQueryParser;

import org.apache.lucene.search.IndexSearcher;

import org.apache.lucene.search.Query;

import org.apache.lucene.search.ScoreDoc;

import org.apache.lucene.store.Directory;

import org.apache.lucene.store.FSDirectory;

import org.apache.lucene.util.Version;

/**

* Servlet implementation class HomePage

*/

public class Searcher extends HttpServlet {

private static final long serialVersionUID = 1L;

public static Document hitDoc;

public static IndexSearcher is;

public static ScoreDoc[] hits;

public static String indexDir = "C:\\Users\\stavros\\Documents\\SearchEngine\\index_directory";

/**

* @see HttpServlet#HttpServlet()

*/

/**

* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)

*/

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

// Set response content type

response.setContentType("text/html");

String searchTerm = "";

String[] actValues = request.getParameterValues("activities");

String[] sightValues = request.getParameterValues("sightseeing");

try{

for(int i=0;i<actValues.length;i++)

{

searchTerm = searchTerm + actValues[i] + " ";

}

for(int i=0;i<sightValues.length;i++)

{

searchTerm = searchTerm + sightValues[i] + " ";

}

}catch (NullPointerException e){

ServletContext sc = this.getServletContext();

RequestDispatcher rd = sc.getRequestDispatcher("/search.jsp");

return;

}

System.out.println(searchTerm);

searchTerm.substring(searchTerm.length() - 1, searchTerm.length());

if (searchTerm==null || searchTerm.isEmpty())

{

ServletContext sc = this.getServletContext();

RequestDispatcher rd = sc.getRequestDispatcher("/search.jsp");

rd.forward(request, response);

return;

}

/*Ορισμός καταλόγου που βρίσκεται το index (παράμετρος). Θα χρησιμοποιηθεί στην ανάκτηση. Ακόμα, ορίζουμε το αρχείο

*common words, προκειμένου να τις παραλήψουμε από το ερώτημα.*/

File path = new File(indexDir);

Directory dir = FSDirectory.open(path);

IndexReader dr = DirectoryReader.open(dir);

is = new IndexSearcher(dr);

File common = new File(indexDir.substring(0, indexDir.length()-15) + "common_words");

FileReader reader = new FileReader(common);

/*Ορίζουμε τα πεδία στα οποία θα εκτελέσουμε την αναζήτηση*/

String[] fields = {"title","description","activities", "sightseeing"};

Analyzer analyzer = new MyAnalyzer(Version.LUCENE_47, WordlistLoader.getWordSet(reader, Version.LUCENE_47));

MultiFieldQueryParser parser = new MultiFieldQueryParser(Version.LUCENE_47, fields, analyzer);

Query q = null;

try {

q = parser.parse(searchTerm);

} catch (Exception e) {

e.printStackTrace();

}

long start = System.currentTimeMillis();

hits = is.search(q, null, 30).scoreDocs;

long end = System.currentTimeMillis();

//System.err.println("Found " + hits.length + " document(s) (in " + (end - start) + " miliseconds) that match the query: '" + searchTerm + "'.");

List<String> results = new ArrayList<String>();

if (hits.length > 0)

{

/*Για κάθε ένα από τα ανακτημένα i συγγράμματα*/

for (int i=0; i < hits.length; i++){

hitDoc = is.doc(hits[i].doc);

results.add("#new#");

/*Εμφάνιση τίτλου συγγράμματος και αριθμού στην διεπαφή.*/

results.add(hitDoc.get("title"));

/*Εμφάνιση συγγραφέα συγγράμματος στην διεπαφή.*/

results.add(hitDoc.get("description"));

/*Εμφάνιση περιγραφής συγγράμματος στην διεπαφή.*/

results.add(hitDoc.get("activities"));

results.add(hitDoc.get("sightseeing"));

/*Εμφάνιση γενικών πληροφοριών ανάκτησης, όπως αριθμό κειμένων και διάρκεια.*/

//System.out.println("Found " + hits.length + " document(s) (in " + (end - start) + " miliseconds) that match the query: '" + searchTerm + "'.");

}

}

else

results.add("No document(s) found (in " + (end - start) + " miliseconds) that match the query: '" + searchTerm + "'.");

ServletContext sc = this.getServletContext();

request.setAttribute("searcher", results);

RequestDispatcher rd = sc.getRequestDispatcher("/results.jsp");

rd.forward(request, response);

}

/**

* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)

*/

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

doGet(request, response);

}

}