MySQL & NetBeans problems

Im doing for faculty some homeworks and have problem with one where I'm suppoused to run Tapestry application from NB and to input some values and then that values should be in DB and print in table on other page. I installed MySQL server and run it from NB but aplication still gives me response

"An unexpected application exception has occurred.

Error invoking service builder method org.apache.tapestry5.hibernate.HibernateModule.buildHibernateSessionManager(HibernateSessionSource, PerthreadManager) (at HibernateModule.java:87) (for service 'HibernateSessionManager'): Canno开发者_C百科t open connection"

If someone know whats the problem please feel free to share... Thanks in advance..

probably, the connection with your mysql database was not stablished, try to look in the configuration file and sure about the mysql user/password and mysql permissions to that user. Then try to re-connect.