Java Sqlite Inner Join returns something but I cannot print it

Question

I have database which has 3 tables, customers, products and Orders. Orders table has 2 foreign keys from the other tables. I want to operate a join operation with these tables. First, let me show you my try on Sqlite:

SELECT c.id, c.name, c.surname, o.productid, o.Datee 
FROM customers c INNER JOIN Orders o 
ON c.id = o.customerid;

And the result is here

So I used this code in Java as:

package autoparkautomation2;

import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class test {

    public static void main(String[] args) throws SQLException {
        Connection con = DriverManager.getConnection("jdbc:sqlite:" + DatabaseInfo.filePath);
        String query = "SELECT c.id, c.name, c.surname, o.productid, o.Datee FROM customer c" 
                     + "INNER JOIN Orders o ON c.id = o.customerid";
        PreparedStatement pstmt = con.prepareStatement(query);
        ResultSet rs = pstmt.executeQuery();
        System.out.println(rs == null); // the statement that checks if rs is null
        int i = 0;
        while(rs.next()) {
            ++i;
            System.out.println(rs.getString("name") + " " + rs.getString("surname") + 
                               rs.getString("productid") + " " + rs.getString("Datee"));
        }
        System.out.println(i);
        con.close();
    } 
}

But the while loop isn't executed, and value of the variable i isn't changing. So I thought that rs value is null because nothing returns from the query. However, the statement that checks if rs is null returns false, meaning that query returns something. Furthermore, I tried to print the values of rs just before the while loop without a loop, only a System.out.Println method, and program throws an error as

Exception in thread "main" java.sql.SQLException: ResultSet closed at org.sqlite.core.CoreResultSet.checkOpen(CoreResultSet.java:76) at org.sqlite.jdbc3.JDBC3ResultSet.findColumn(JDBC3ResultSet.java:39) at org.sqlite.jdbc3.JDBC3ResultSet.getString(JDBC3ResultSet.java:446) What's wrong with my code? I scanned a lot of solutions, but many of them were about Android whose codes seemed a little bit confusing and scary. I am newbie to JDBC and Sqlite. Thx in advance for your replies.