MySQL error NoClassDefFoundError

When i run my plugin while trying to use sql from http://forums.bukkit.org/threads/lib-tut-mysql-sqlite-bukkit-drivers.33849/ i get this error

Code:

2012-07-02 11:52:22 [SEVERE] Could not load 'plugins\SteelSecurity.jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: java.lang.NoClassDefFoundError: lib/PatPeter/SQLibrary/MySQL
	at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:149)
	at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:305)
	at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:230)
	at org.bukkit.craftbukkit.CraftServer.loadPlugins(CraftServer.java:213)
	at org.bukkit.craftbukkit.CraftServer.<init>(CraftServer.java:189)
	at net.minecraft.server.ServerConfigurationManager.<init>(ServerConfigurationManager.java:53)
	at net.minecraft.server.MinecraftServer.init(MinecraftServer.java:166)
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:432)
	at net.minecraft.server.ThreadServerApplication.run(SourceFile:492)
Caused by: java.lang.NoClassDefFoundError: lib/PatPeter/SQLibrary/MySQL
	at net.othercraft.steelsecurity.data.DatabaseManager.<init>(DatabaseManager.java:9)
	at net.othercraft.steelsecurity.Main.<init>(Main.java:40)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
	at java.lang.reflect.Constructor.newInstance(Unknown Source)
	at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:145)
	... 8 more
Caused by: java.lang.ClassNotFoundException: lib.PatPeter.SQLibrary.MySQL
	at java.net.URLClassLoader$1.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(Unknown Source)
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:41)
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:29)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	... 15 more

how do i fix this

 

did you include it ?

 

When you build a bukkit plugin and need external plugins , you should go to your build path -> configure build path -> add exteranal jars -> add l external plugins. If you've done that, then you should be sure to have the plugin is in your plugins folder.