https://www.cnblogs.com/jcz1206/p/4344664.html

HTTP Status 500 - The absolute uri: http://java.sun.com/jsp/jstl/core cannot be resolved in either web.xml or the jar files deployed with this application

警告: com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@983b64 -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception: 

java.sql.SQLException: Acc?¨s refus?? pour l'utilisateur: 'root'@'@localhost' (mot de passe: OUI)