mypackage.DownloadColl.java Source code

Introduction

Here is the source code for mypackage.DownloadColl.java

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/*
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 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package mypackage;

import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.DBObject;
import com.mongodb.MongoClient;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Iterator;
import java.util.Set;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.json.JSONArray;
import org.json.JSONObject;

/**
 *
 * @author Kapil Gehlot
 */
public class DownloadColl extends HttpServlet {

    String dir = "C:\\Users\\Kapil Gehlot\\Documents";

    private File checkExist(String fileName) {

        File f = new File(dir + "\\" + fileName);
        if (f.exists()) {
            f.delete();
        }
        return f;
    }

    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        try (PrintWriter out = response.getWriter()) {
            /* TODO output your page here. You may use following sample code. */
            try {
                String dbname = request.getParameter("dbname");
                String collname = request.getParameter("collname");
                MongoClient mongoClient = new MongoClient("localhost", 27017);
                DB db = mongoClient.getDB(dbname);
                // out.print(dbname+collname);

                JSONObject jSONObject_coll = new JSONObject();
                JSONArray jSONObject_doc = new JSONArray();
                DBCollection dBCollection = db.getCollection(collname);

                DBCursor dBCursor = dBCollection.find();
                while (dBCursor.hasNext()) {
                    DBObject next1 = dBCursor.next();
                    jSONObject_doc.put(next1);

                }
                //out.print(dbname+collname);
                String filename = dbname + "_" + collname + ".json";

                jSONObject_coll.put(collname, jSONObject_doc);
                //out.print(jSONObject_coll);
                File file = checkExist("mongocollection.json");
                FileWriter fileWriter = new FileWriter(file);
                fileWriter.write(jSONObject_coll.toString());
                fileWriter.close();
                response.setContentType("APPLICATION/OCTET-STREAM");
                response.setHeader("Content-Disposition", "attachment;filename=\"" + filename + "\"");
                FileInputStream fis = new FileInputStream(dir + "\\" + "mongocollection.json");
                int i;
                while ((i = fis.read()) != -1) {
                    out.write(i);

                }
                fis.close();
                out.close();
            } catch (Exception e) {

            }
        }
    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /**
     * Handles the HTTP <code>GET</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Handles the HTTP <code>POST</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Returns a short description of the servlet.
     *
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>

}