Question

I am having problem in connecting to mysql database when I am using this code.I have already checked that port number is 3128.So there is no issue about that.I checked it and I think problem is in

connection= DriverManager.getConnection("jdbc:mysql://localhost:3128/gcc","root", "root");

There is no error when compiling.Can someone help me with this?

import java.awt.*;
import java.applet.*;
import java.awt.event.*;
import java.sql.*;
//import java.net.*;

public class Main extends Applet implements ActionListener
{
 TextArea tarea;
 Button bsubmit;

 public void init()
 {
  setBackground(new Color(0,0,0));
  setForeground(Color.white);

  Label l1=new Label("Write your code : ");
  l1.setFont(new Font("lucida console",Font.PLAIN,25));
  l1.setSize(200,30);

  tarea=new TextArea();
  tarea.setFont(new Font("lucida console",Font.PLAIN,18));
  tarea.setForeground(new Color(0,0,0));
  tarea.setSize(600,250);

  bsubmit=new Button("Submit");
  bsubmit.setFont(new Font("lucida console",Font.PLAIN,15));
  bsubmit.setBackground(new Color(255,255,255));
  bsubmit.setForeground(new Color(0,0,0));
  bsubmit.setSize(100,30);

  add(l1);
  add(tarea);
  add(bsubmit);

  setLayout(null);
  l1.setLocation(40,40);
  tarea.setLocation(40,100);
  bsubmit.setLocation(40,400);

  bsubmit.addActionListener(this);
 }

 public void actionPerformed(ActionEvent ae)
 {
  if(ae.getSource()==bsubmit)
  {
   Connection connection=null;
   try 
   {
    Class.forName("com.mysql.jdbc.Driver");
    connection= DriverManager.getConnection("jdbc:mysql://localhost:3128/gcc","root", "root");
    Statement stmt = connection.createStatement();
    stmt.executeUpdate("CREATE TABLE test2 (code VARCHAR(254))");
   } 
   catch (Exception e) {}
  }  
 }
}

Answer 1

Java database drivers are the worst thing. I remember, I had my first JDBC driver (or let’s say: a working transaction;) to be installed within “only” 2 days, and I know a guy who had two weeks, lol.

In most of the time the very last issue is a SQL problem. Because you need to give the rights to the user as “username”@”IP”. You find the user information in the database information_schema in the table user_privileges. There exist enough tutorials how to handle them, but I like ‘username’@’%’ to get all privileges in a test environment. smile

This may help you: http://dev.mysql.com/doc/refman/5.1/de/adding-users.html

Yeah, those damn SQL rights… ;D

@Luiggi: That’s certainly no silly question! I had hours to find that out!! I mean, which beginner knows that the Java sql classes are only xxxxxxx interfaces with no implemented code?! %D

EDIT

And anyway:

Class.forName("...driverblabla...");

Does this code line look like Java? Nooo, its a xxxxxx compiler hack or whatever! But it works, it really DOES something!!

Oh, but for certain driver implementations this won’t work, you need this:

Class.forName("...driverblabla...").newInstance();

LMAO!

@Abhinav: Add this line above your getConnection-line:

Class.forName("com.mysql.jdbc.driver").newInstance();

And don’t think one second about what it exactly does (I know it, but…let’s screw it 😉