This message can also be displayed, if, like me, you run your application with the Maven plugin for Tomcat:
mvn clean install tomcat7:run
and you have a provided
scope element in your Maven dependency:
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.36</version>
<scope>provided</scope>
</dependency>
The provided
scope will prevent the connector from being part of the war
archive and the Tomcat plugin will find no connector to establish the database connection.
Simply removing the provided
scope from the dependency solves the issue.