Java + Oracle(export)+PostgreSQL

package DBTransfer;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.ResultSet;
import java.sql.PreparedStatement;
import java.sql.Connection;
import java.sql.*;
import java.lang.*;
 
public class MainFrame extends JFrame {
  JPanel contentPane;
  BorderLayout borderLayout1 = new BorderLayout();
  java.sql.Connection oraclecon=null;
  java.sql.Connection postgrecon=null;
  sun.jdbc.odbc.ee.DataSource ds = new sun.jdbc.odbc.ee.DataSource();
  public MainFrame() {
    enableEvents(AWTEvent.WINDOW_EVENT_MASK);
    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }
  //Component initialization
  private void jbInit() throws Exception  {
//--------- Database Oracle -----------------------------------------------------
//Inicializacija oracle
    try {
        Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();
        System.out.println("Instance initialized - ORACLE .");
    } catch (Exception ex) {
        System.out.println("Can't initialize instance : "+ex.getMessage());
    }
    try {
oraclecon = DriverManager.getConnection("jdbc:oracle:thin:@10.20.100.240:1521:bill","mind","mind");
      System.out.println("Connection - ORACLE Database: " + oraclecon);
    } catch (SQLException ex) {
      System.out.println("SQLException: " + ex.getMessage());
      System.out.println("SQLState: " + ex.getSQLState());
      System.out.println("VendorError: " + ex.getErrorCode());
      System.exit(0);
    }
//------END Database Oracle -----------------------------------------------------
//------Database PostgreSQL -----------------------------------------------------
    try {
       Class.forName("org.postgresql.Driver").newInstance();
       System.out.println("Instance initialized.- PostgreSQL Database");
   } catch (Exception ex) {
       System.out.println("Can't initialize instance:"+ex.getMessage());
   }
   try {
postgrecon = DriverManager.getConnection("jdbc:postgresql://localhost/xxx", "agas", "agas");
     System.out.println("Connection - PostgreSQL : " + postgrecon);
   } catch (SQLException ex) {
     System.out.println("SQLException: " + ex.getMessage());
     System.out.println("SQLState: " + ex.getSQLState());
     System.out.println("VendorError: " + ex.getErrorCode());
     System.exit(0);
   }
//------END Database PostgreSQL     ---------------------------------------------
 
    String strSQL1, strSQL2;
    PreparedStatement pstmt = null;
    try {
      Statement stmt2 = null, stmt1 = null;
      stmt1 = postgrecon.createStatement();
      stmt2 = oraclecon.createStatement();
      strSQL1 = "SELECT *  FROM voipcdr";
      ResultSet rs = stmt1.executeQuery(strSQL1);
      int i = 0;
      while (rs.next()) {
        strSQL2  = "INSERT INTO voipcdr ( callid,regtrunkid) ";