JDBC-Treiber sauber abmelden beim abmelden bei Tomcat.
30-Mar-2017 14:12:26.228 WARNING [Thread-5] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesJdbc The web application [ROOT] registered the JDBC driver [org.postgresql.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
Dieser Bug ist sehr Kritisch, weil er so den Projekteserver stoppt!