Java servlet upload csv

package doLoad;

import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemFactory;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import javax.servlet.Servlet;

@WebServlet("/uploadcsv")
public class UploadCsv  extends HttpServlet implements Servlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

         response.setContentType("text/html");
         PrintWriter out=response.getWriter();
        try {

                 String category = "";
                 InputStream csvfile = null;

                 FileItemFactory factory = new DiskFileItemFactory();

                 boolean isMultipart = ServletFileUpload.isMultipartContent(request);

                 ServletFileUpload upload = new ServletFileUpload(factory);
                 Map<String, List<FileItem>> file = upload.parseParameterMap(request);

                 Iterator entries = file.entrySet().iterator();
                 while (entries.hasNext()) {
                      Entry thisEntry = (Entry) entries.next();
                      List<FileItem> value = (List) thisEntry.getValue();
                        for (FileItem uploadItem : value) {
                            csvfile = uploadItem.getInputStream();
                          }  // end of for loop
                 }//while

                InputStreamReader isr = new InputStreamReader(csvfile);
                BufferedReader reader = new BufferedReader(isr);

                String text = "";
                reader.readLine();

                    // We read the file line by line and later will be displayed on the browser page.
                while ((text = reader.readLine()) != null) {
                    String[] columns = text.split(",");
                    System.out.println("count columns" + columns.length);
                    String rowdata = "";
                        for (String value : columns) {
                            rowdata += "'" + value + "',";
                        }
                       rowdata = rowdata.substring(0, rowdata.length() - 1);
                       String select = category;
                         try {
                               Class.forName("oracle.jdbc.driver.OracleDriver");
                               Connection  con=DriverManager.getConnection("jdbc:oracle:thin:@//10.250.193.103:1521/optunai", "TUNAIREPORT", "TUNAIREPORT#2015");
                               Statement stmt=con.createStatement();
                               String query = "insert into csvfile(name,mail) values(" + rowdata + ")";
                               stmt.executeUpdate(query);
                                out.println("Successfully uploaded");
                              }//try
                              catch (Exception e) {
                               out.println("Error Try Again"+e.getMessage());
                               } //catch
                     }

           }// try
          catch (Exception e) {
              out.println("Error Try Again"+e.getMessage());
        }
    }


}


<form action="uploadcsv" enctype="multipart/form-data" method="post">
<input name="file" type="file">
<input type="submit" value="submit">
</form>