Find out which JAR file contains the problematic Java class. For example, in the case of com.mysql.jdbc.driver, the JAR file that contains it is mysql-connector-java.jar.
Check whether this JAR is present in the application classpath. If not, the JAR should be added to the classpath in Java and the application should be recompiled.
f that JAR is already present in the classpath, make sure the classpath is not overridden (e.g. by a start-up script). After finding out the exact Java classpath used by the application, the JAR file should be added to it.
To fix the Java exception, the mysql-connector JAR should be included in the application classpath.