Tomcat does not recognize the MySQL .jar library

I tried several different ways such that Tomcat loads the MySQL drivers when running my web application. I'm using Ubuntu 8.04, and the libraries come from the开发者_运维百科 libmysql-java package. They are located in the directory shown below:

~$ ls /usr/share/java/mysql*
/usr/share/java/mysql-connector-java-5.1.5.jar

My CLASSPATH includes this file:

~$ echo $CLASSPATH
.:/usr/lib/jvm/java-6-sun/bin:/usr/local/tomcat/lib/servlet-api.jar:/usr/share/java/mysql-connector-java-5.1.5.jar

I even put a copy of the .jar file in my WEB-INF/lib/ directory in my web app:

/usr/local/tomcat/webapps/ohms/WEB-INF/lib$ ls
mysql-connector-java-5.1.5.jar

After making these changes, I restart Tomcat, re-compile my classes, restart Tomcat again. Also, I am importing the necessary libraries using import java.sql.*;

However I am still getting the java.lang.ClassNotFoundException: com.mysql.jdbc.Driver error when it runs the line Class.forName("com.mysql.jdbc.Driver").newInstance();

What am I doing wrong here?

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Put it in TOMCAT_HOME/lib. (I seem to recall that on older versions of Tomcat, it's TOMCAT_HOME/server/lib?)

It's not going to work in WEB-INF/lib since the container needs access to the library, and, that is putting it in the classloader of one web app, not the container. While I would have imagined the CLASSPATH approach would work, it's not the standard way to do this. Perhaps there is some other snag that's preventing it from working.

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Tomcat ignores any CLASSPATH environment variable, as do all Java EE app servers and IDEs. That does you no good at all. I don't set one on any machine that I use.

The JAR needs to go in Tomcat server/lib for Tomcat 5.x and /lib for 6.x.

You don't need to call newInstance(); Class.forName("com.mysql.jdbc.Driver") is sufficient to register the driver class.

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Copy mysql connector to /usr/share/tomcat7/lib

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One other thing you might want to do, if you don't want to put a file into the Tomcat lib directory. It states in catalina.sh that it will check setenv.sh for a variable set to include outside jars. So for example, as I did it, you may create this file:

$CATALINA_HOME/bin/setenv.sh

with the contents:

CLASSPATH=lib/mysql-connector-java-5.1.33-bin.jar

The path to the jar will be relative to where you start up Tomcat, also known as your working directory. So, for example, in my case I start up Catalina from an Ant script two levels up from $CATALINA_HOME and my lib directory is directly underneath that point.