When you encounter exceptions like this, the most useful information is generally at the bottom of the stacktrace:
Caused by: java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
...
at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:246)
The problem is that Tomcat can't find com.mysql.jdbc.Driver
. This is usually caused by the JAR containing the MySQL driver not being where Tomcat expects to find it (namely in the webapps/<yourwebapp>/WEB-INF/lib
directory).