Problems with loading mySQL driver in Java

It doesn't work. I put the zip file in almost every directory in the c:/jbuilder6/

I don't know... Still get the 3 problems... Should I try an earlier version or maybey jbuilder 7 or 8?

Run this with the parameter 'java.ext.dirs' (no quotes) and tell me what you see:

public class Props {

  public static void main(String[] args){
    if(args.length > 0){
     for(int i = 0;i < args.length;i++){
      System.out.println(System.getProperty(args[0]));
     }
    }
    else {
      System.getProperties().list(System.out);
    }
  }
}

It says:

"Props.java": Error #: 302 : cannot access class java.ext.dirs; java.io.IOException: class not found: class java.ext.dirs at line 2, column 17

You're not compiling and/or running it properly.

Compile

javac Props.java

Run

java Props java.ext.dirs

Ducolo,
The problem you're seeing is because the driver file is not in the classpath.

In the windows console, type out the following
set CLASSPATH=%CLASSPATH%;directory_with_driver_zip\mysql-connector-java-3.0.4-gamma.zip

(replace 'directory_with_driver_zip' with the full path to the directory where you've kept the zip file)

then, execute your program with:
java opstarten

Hope this helps!

I executed the following:

1st:
c:\JBuilder6\jdk1.3.1\bin\javac c:\Quiztool\src\quiztool\props.java

2nd:
c:\JBuilder6\jdk1.3.1\bin\java c:\Quiztool\src\quiztool\props java.ext.dirs

Then went back to Jbuilder, running, error:
"Props.java": Error #: 302 : cannot access class java.ext.dirs; java.io.IOException: class not found: class java.ext.dirs at line 2, column 17

I still don't have a clue, do you?

reg.
Duco

Please do NOT duplicate my answers dronacharya!

The class is called 'Props', not 'props'

>>Please do NOT duplicate my answers dronacharya

My answer will solve the problem of 'classpaths' without using them - classpaths are inherently messy and should be avoided wherever possible. Personally, i *never* have a classpath set.

CEHJ,
Just because I've happened to reply to two separate questions after you've done so, it doesn't mean that I'm copying your answers. And I believe we're both here to solve problems, not bicker. I think I'll just avoid responding to anything else so that you'll cool off a bit :-).
Relax!
Thanks,
Dronacharya

I tried it exactly with the capitals:

is says:

cannot resolve symbol
symbol: class dirs
location: package ext
import java.ext.dirs;
                ^

I just wanted to say thanks for your help. I really appreciate it. If I make the deadline or not.

Please...be nice to each other. We're all here to help each other, right? Peace on Earth. Bless God

Amen

>>import java.ext.dirs;


Where has this come from? - it wasn't in my code

This was your message:
--------
Run this with the parameter 'java.ext.dirs' (no quotes) and tell me what you see:

public class Props {

 public static void main(String[] args){
   if(args.length > 0){
    for(int i = 0;i < args.length;i++){
     System.out.println(System.getProperty(args[0]));
    }
   }
   else {
     System.getProperties().list(System.out);
   }
 }
}
------
this means that i wrote:
import java.ext.dirs;

Or is that not right?

No. You don't have to import anything - all classes used are in java.lang package.

I have the following package:

package quiztool;

Should i use:

package com.mysql.jdbc.jdbc2;
or something like that?

Just run my code and tell me what you see.

C:\JBuilder6\jdk1.3.1\bin\javaw -classpath "C:\Quiztool\classes;C:\JBuilder6\jdk1.3.1\demo\jfc\Java2D\Java2Demo.jar;C:\JBuilder6\jdk1.3.1\jre\lib\i18n.jar;C:\JBuilder6\jdk1.3.1\jre\lib\jaws.jar;C:\JBuilder6\jdk1.3.1\jre\lib\rt.jar;C:\JBuilder6\jdk1.3.1\jre\lib\sunrsasign.jar;C:\JBuilder6\jdk1.3.1\lib\dt.jar;C:\JBuilder6\jdk1.3.1\lib\htmlconverter.jar;C:\JBuilder6\jdk1.3.1\lib\tools.jar"  quiztool.opstarten

That's showing the command line for running *your* code(?)

I added a class to "confige JDK". It now says:

C:\JBuilder6\jdk1.3.1\bin\javaw -classpath "C:\Quiztool\classes;C:\JBuilder6\jdk1.3.1\demo\jfc\Java2D\Java2Demo.jar;C:\JBuilder6\jdk1.3.1\jre\lib\i18n.jar;C:\JBuilder6\jdk1.3.1\jre\lib\jaws.jar;C:\JBuilder6\jdk1.3.1\jre\lib\rt.jar;C:\JBuilder6\jdk1.3.1\jre\lib\sunrsasign.jar;C:\JBuilder6\jdk1.3.1\lib\dt.jar;C:\JBuilder6\jdk1.3.1\lib\htmlconverter.jar;C:\JBuilder6\jdk1.3.1\lib\tools.jar;C:\JBuilder6\jdk1.3.1\jre\mysql-connector-java-3.0.4-gamma.zip"  quiztool.opstarten

That's the only thing i see then. The program runs just fine...

Just compile and run my code from a normal DOS Window.

It says:
Exception in thread "main" java.lang.NoClassFoundError: c:\Quiztool\src\quiztool\Props

In the JBuilder, have you addded this package using:

Project-->Add Files/Packages

If no try this. I had a similar problem with JBuilder5 and another JDBC driver.

I was simply trying to help you sort out that horrible mess of classpath you've just shown me. For one thing, windows has a habit of running out of environment variable space when things like this get too long.

If you wnat to keep your classpath then copy

mysql-connector-java-3.0.4-gamma.zip

to

C:\JBuilder6\jdk1.3.1\jre\lib\ext and change

C:\JBuilder6\jdk1.3.1\jre\mysql-connector-java-3.0.4-gamma.zip

to

C:\JBuilder6\jdk1.3.1\jre\lib\ext\mysql-connector-java-3.0.4-gamma.zip

Sorry, better in Project properties-->Paths-->Required lobraries-->Add

Try this.

The mysql-connector-java-3.0.4-gamma.zip contains the jar file(s) that you need to to place in your ext directory or your classpath.

You must extract the zip first (at least the mysql-connector-java-3.0.4-gamma-bin.jar file). Open the zip and read the "readme" file for installation instructions.

You also need to catch the ClassNotFoundException thrown by Class.forName().

I can load the driver now. It was a catch/try case...

Now i want to connect to an online database. Is the following possible?

"jdbc:mysql://ftp://neushoorn:Chris83@home.wanadoo.nl/Nathalie/Toets.db?user=dba&password=SQL");

or should it be this?

"jdbc:mysql://ftp://neushoorn:Chris83@home.wanadoo.nl/Nathalie/Toets.db","user=dba","password=SQL");
     

thankx....

>>I added a class to "confige JDK". It now says:...

That was what fixed the problem almost certainly.

>>or should it be this?

You shouldn't have more than one protocol, so just lose the ftp://

OK, but how must it be?

"jdbc:mysql://neushoorn:Chris83@home.wanadoo.nl/Nathalie/Toets.db?user=dba&password=SQL");

or should it be this?

"jdbc:mysql://neushoorn:Chris83@home.wanadoo.nl/Nathalie/Toets.db","user=dba","password=SQL");

it still doesn't connect...

I was wrong, it doesnt load the driver. This is the full script...

package quiztool;

import java.sql.Connection;
import java.sql.Statement;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.ResultSet;
import java.sql.Driver;
import java.io.*;


/**
 * Title:        QuizTool
 * Description:  Dit is de quiz tool die nodig is om de digitale quiz te beheren. Deze tool wordt gemaakt in opdracht voor dhr Berry.
 * Copyright:    Copyright (c) 2002
 * Company:      HHS
 * @author Nathalie Vrolijk, Christian Güde, Duco Risselada, Ronald van der Linden
 * @version 1.0
 */

public class opstarten {

  public opstarten() {
      //driver wordt geladen
      try {
        Class.forName ("com.mysql.jdbc.Driver");//.newInstance();
      } //end try

      catch (ClassNotFoundException classNotFound ) {
        System.err.println("Failed to load JDBC/ODBC driver.");
      }; //end catch

     java.sql.Connection conn;

      try {
      conn = DriverManager.getConnection(
      "jdbc:mysql://neushoorn:Chris83@home.wanadoo.nl/Nathalie/Toets.db?user=dba&password=SQL");
      } //end try

      catch (Exception e) {
      System.err.println("problems connecting");
      } //end catch


  } // end public opstarten
  public static void main(String[] args) {
    opstarten opstarten1 = new opstarten();
    FrameHoofdscherm FrameHoofdscherm1 = new FrameHoofdscherm();
  }
}
----

why can't i get this thing to work probably...

:(

I would recommend you try to connect from MySql itself until you get the string right. The first one looks better btw

yep...

I just wanna say: thankx for all the help, althoug i'm not finished, i respect you'r help a lot...

OK, so I live to solve the problem next day...

Does anybody has a clue why I can't load the driver??

I've given you two different ways to load the driver already, but here goes again:

classpaths are pretty grim, but since they are used by JBuilder, do the following:

1. mysql-connector-java-3.0.4-gamma.zip
 should be in C:\JBuilder6\jdk1.3.1\jre\lib\ext. If it's not in there, move it there and get rid of it elsewhere on the file system.
2. Add that package at that path to JBuilder

I did the following:

Database Drivers page of the Tools|Enterprise Setup dialog box

here i added the mysql driver...

the help function says:

"Click OK. JBuilder creates a new .library file in the JBuilder /lib directory with the name you specified (for example, InterClient.library). It also returns you to the Database Drivers page which displays the name of the corresponding .config file in the list which will be derived from the library file (for example, InterClient.config). Select the new .config file in the database driver list and click OK. This places the .config file in the JBuilder /lib/ext directory."

but still it doesn't work...

If you don't follow my advice i can't help you

Oh and remove the package mysql-connector-java-3.0.4-gamma.zip from JBuilder *first* if it's not at the path i said it should be

It works!!! With a little help from my teacher and you (CEHJ), i can load the driver.

Now, how do i connect to a mySQL database?

is it possible that the database is called: thema.MYD or something?

Not to say the same thing twice, but since it hasn't been attempted yet and my mailbox is filling up with messages from this question, Ill say it again (hopefully more clearly):

The "mysql-connector-java-3.0.4-gamma.zip" file is a zip file that CONTAINS the jar file that you need to place in your classpath or ext directory. The zip file itself placed in the classpath or ext directory WILL NOT WORK.

There are class files in the distribution. However they are NOT in the appropriate directories within the zip to work properly. You would have to unzip the whole file and put the directory "mysql-connector-java-3.0.4-gamma" in your classpath. (I don't recommend this).

Simply extract the "mysql-connector-java-3.0.4-gamma-bin.jar" file from the zip and place it in your classpath or ext directory.

View the readme included in the zip for more explicit instructions.

>>Now, how do i connect to a mySQL database?

OK - we've been through *that* before as well. This was my suggestion:

>>I would recommend you try to connect from MySql itself until you get the string right. The first one looks better btw

I can't tell you what the database is, but i recommend you get the connection parameters sorted out *in MySql* i.e. from the program independently of Java until you can connect. Then transfer the parameters into your Java program

OK, i will try it tommorrow. Another day, another JAVA-day....