exception when accessing application

exception when accessing application
resumid:

org.apache.jasper.JasperException: javax.servlet.ServletException: Error creating bean with name 'mBeanLogin': Invocation of init method failed; nested exception is org.springframework.transaction.CannotCreateTransa ctionException: Could not open JPA EntityManager for transaction; nested exception is javax.persistence.PersistenceException: org.hibernate.exception.GenericJDBCException: Cannot open connection
at org.apache.jasper.servlet.JspServletWrapper.handle JspException(JspServletWrapper.java:549)

...
Caused by: javax.servlet.ServletException: Error creating bean with name 'mBeanLogin': Invocation of init method failed; nested exception is org.springframework.transaction.CannotCreateTransa ctionException: Could not open JPA EntityManager for transaction; nested exception is javax.persistence.PersistenceException: org.hibernate.exception.GenericJDBCException: Cannot open connection
at javax.faces.webapp.FacesServlet.service(FacesServl et.java:606)
...

Caused by: org.springframework.beans.factory.BeanCreationExce ption: Error creating bean with name 'mBeanLogin': Invocation of init method failed; nested exception is org.springframework.transaction.CannotCreateTransa ctionException: Could not open JPA EntityManager for transaction; nested exception is javax.persistence.PersistenceException: org.hibernate.exception.GenericJDBCException: Cannot open connection
at org.springframework.beans.factory.annotation.InitD estroyAnnotationBeanPostProcessor.postProcessBefor eInitialization(InitDestroyAnnotationBeanPostProce ssor.java:135)
...

Caused by: org.springframework.transaction.CannotCreateTransa ctionException: Could not open JPA EntityManager for transaction; nested exception is javax.persistence.PersistenceException: org.hibernate.exception.GenericJDBCException: Cannot open connection
at org.springframework.orm.jpa.JpaTransactionManager. doBegin(JpaTransactionManager.java:427)
...

Caused by: javax.persistence.PersistenceException: org.hibernate.exception.GenericJDBCException: Cannot open connection
at org.hibernate.ejb.AbstractEntityManagerImpl.throwP ersistenceException(AbstractEntityManagerImpl.java :614)
at org.hibernate.ejb.TransactionImpl.begin(Transactio nImpl.java:41)
at org.springframework.orm.jpa.DefaultJpaDialect.begi nTransaction(DefaultJpaDialect.java:70)
at org.springframework.orm.jpa.vendor.HibernateJpaDia lect.beginTransaction(HibernateJpaDialect.java:59)
at org.springframework.orm.jpa.JpaTransactionManager. doBegin(JpaTransactionManager.java:377)
... 104 more
Caused by: org.hibernate.exception.GenericJDBCException: Cannot open connection
at org.hibernate.exception.SQLStateConverter.handledN onSpecificException(SQLStateConverter.java:126)
at
....

Caused by: java.sql.SQLException: com.mchange.v2.resourcepool.ResourcePoolException: Attempted to use a closed or broken resource pool
at com.mchange.v2.resourcepool.BasicResourcePool.ensu reNotBroken(BasicResourcePool.java:920)
at com.mchange.v2.resourcepool.BasicResourcePool.chec koutResource(BasicResourcePool.java:191)


what can this be?