Exception in thread "main" related to CLASSPATH and unable to load driver??

Question

Hi,
I am a JAVA beginner, I have met some problems cannot solve, can somebody help?
My OS is Windows2000
Java SDK in C:\j2sdk-1_4_2_04 and Java JRE in C:\Program Files\Java\j2re1.4.2_04 [Installation: j2sdk-1_4_2_04-windows-i586-p.exe]
MySQL in C:\mysql [Installation: mysql-4.0.18-win.zip]
MyODBC in C:\Download\MYODBC [Installation: MyODBC-3.51.06.exe]
MyJDBC in C:\mysql-connector-java-3.0.11-stable [Installation: mysql-connector-java-3.0.11-stable.zip]
Enviornment Variables Settings
PATH = C:\WINNT\system32;C:\WINNT;C:\WINNT\System32\Wbem;C:\j2sdk1.4.2_04\bin;C:\mysql\bin
JAVA_HOME = C:\j2sdk1.4.2_04
(CASE ONE) - While I didn't set a new Enviornment Variable for CLASSPATH
HelloWorld.class can work properly and LoadDriver.class cannot work due to Unable to load Driver (As below)
C:\JavaTry>javac HelloWorld.java
C:\JavaTry>java HelloWorld
Hello World!
C:\JavaTry>javac LoadDriver.java
C:\JavaTry>java LoadDriver
Unable to load driver.
java.lang.ClassNotFoundException: org.gjt.mm.mysql.Driver
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at LoadDriver.main(LoadDriver.java:7)
(CASE TWO) - While I set a new Enviornment Variable for CLASSPATH (No matter which settings as below)
CLASSPATH = C:\mysql-connector-java-3.0.11-stable\mysql-connector-java-3.0.11-stable-bin.jar
CLASSPATH = C:\mysql-connector-java-3.0.11-stable
CLASSPATH = C:\mysql-connector-java-3.0.11-stable\com;C:\mysql-connector-java-3.0.11-stable\org
Both the HelloWorld.class and LoadDriver cannot work properly due to Exception in thread "main" java.lang.NoClassDefFoundError (As below)
C:\JavaTry>javac HelloWorld.java
C:\JavaTry>java HelloWorld
Exception in thread "main" java.lang.NoClassDefFoundError: HelloWorld
C:\JavaTry>javac LoadDriver.java
C:\JavaTry>java LoadDriver
Exception in thread "main" java.lang.NoClassDefFoundError: LoadDriver
Below are the JAVA scripts which I used
-> HelloWorld.java
public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello World!");
-> LoadDriver.java
import java.sql.*;
public class LoadDriver {
public static void main(String[] Args) {
try {
Class.forName("org.gjt.mm.mysql.Driver").newInstance();
/* Class.forName("com.mysql.jdbc.Driver").newInstance(); <- either one try the same */
} catch (Exception E) {
System.err.println("Unable to load driver.");
E.printStackTrace();
Moreover, I saw some information only standalone application need to set CLASSPATH, right??

Answer 1

My problem "unable to load driver" have solved.
I set the CLASSPATH = C:\mysql-connector-java-3.0.11-stable\mysql-connector-java-3.0.11-stable-bin.jar
and try
java -cp ".";%CLASSPATH% LoadDriver
Thanks masnare again :> and who provided the link http://www.kevinboone.com/classpath.html in the forums others similar topics, actually I forgot which topic and who, so... :P no matter whom thanks very much :)