Cannot Open Connection Exception: Generic JDBC Exception

Question

I thought I was getting this error because I didn't have the ojdbc14.jar deployed inside <jbossas.home>/common/lib . The issue still remains even after I did it.

Stacktrace

    HTTP Status 500 -

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

javax.persistence.PersistenceException: org.hibernate.exception.GenericJDBCException: Cannot open connection
    org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:614)
    org.hibernate.ejb.QueryImpl.getResultList(QueryImpl.java:76)
    gov.medicaid.services.impl.RegistrationServiceBean.findByUsername(RegistrationServiceBean.java:156)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

root cause

org.hibernate.exception.GenericJDBCException: Cannot open connection
    org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:126)
    org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:114)
    org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
    org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:52)
    org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:449)
    org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:167)
    org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:161)
    org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1573)
    org.hibernate.loader.Loader.doQuery(Loader.java:696)

root cause

org.jboss.util.NestedSQLException: Unable to get managed connection for MitaDS; - nested throwable: (javax.resource.ResourceException: Unable to get managed connection for MitaDS)
    org.jboss.resource.adapter.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:95)
    org.hibernate.ejb.connection.InjectedDataSourceConnectionProvider.getConnection(InjectedDataSourceConnectionProvider.java:46)
    org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:446)
    org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:167)
    org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:161)
    org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1573)

root cause

javax.resource.ResourceException: Unable to get managed connection for MitaDS
    org.jboss.resource.connectionmanager.BaseConnectionManager2.getManagedConnection(BaseConnectionManager2.java:441)
    org.jboss.resource.connectionmanager.TxConnectionManager.getManagedConnection(TxConnectionManager.java:381)
    org.jboss.resource.connectionmanager.BaseConnectionManager2.allocateConnection(BaseConnectionManager2.java:496)
    org.jboss.resource.connectionmanager.BaseConnectionManager2$ConnectionManagerProxy.allocateConnection(BaseConnectionManager2.java:941)
    org.jboss.resource.adapter.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:89)
    org.hibernate.ejb.connection.InjectedDataSourceConnectionProvider.getConnection(InjectedDataSourceConnectionProvider.java:46)
    org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:446)
    org.jboss.ejb3.ENCPropagationInterceptor.invoke(ENCPropagationInterceptor.java:41)
    org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
    org.jboss.ejb3.BlockContainerShutdownInterceptor.invoke(BlockContainerShutdownInterceptor.java:67)

root cause

org.jboss.resource.JBossResourceException: Could not create connection; - nested throwable: (java.sql.SQLException: Io exception: The Network Adapter could not establish the connection)
    org.jboss.resource.adapter.jdbc.local.LocalManagedConnectionFactory.getLocalManagedConnection(LocalManagedConnectionFactory.java:225)
    org.jboss.resource.adapter.jdbc.local.LocalManagedConnectionFactory.createManagedConnection(LocalManagedConnectionFactory.java:195)
    org.jboss.resource.connectionmanager.InternalManagedConnectionPool.createConnectionEventListener(InternalManagedConnectionPool.java:633)
    org.jboss.resource.connectionmanager.InternalManagedConnectionPool.getConnection(InternalManagedConnectionPool.java:267)
    org.jboss.resource.connectionmanager.JBossManagedConnectionPool$BasePool.getConnection(JBossManagedConnectionPool.java:622)
    org.jboss.resource.connectionmanager.BaseConnectionManager2.getManagedConnection(BaseConnectionManager2.java:404)
    org.jboss.resource.connectionmanager.TxConnectionManager.getManagedConnection(TxConnectionManager.java:381)
    org.jboss.resource.connectionmanager.BaseConnectionManager2.allocateConnection(BaseConnectionManager2.java:496)
    org.jboss.resource.connectionmanager.BaseConnectionManager2$ConnectionManagerProxy.allocateConnection(BaseConnectionManager2.java:941)
    org.jboss.resource.adapter.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:89)
    org.hibernate.ejb.connection.InjectedDataSourceConnectionProvider.getConnection(InjectedDataSourceConnectionProvider.java:46)
    org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:446)
    org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:167)
    org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:161)
    org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1573)
    org.hibernate.loader.Loader.doQuery(Loader.java:696)
    org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:259)
    org.hibernate.loader.Loader.doList(Loader.java:2228)
    org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2125)
    org.hibernate.loader.Loader.list(Loader.java:2120)
    org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:401)
    org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:361)
    org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:196)
    org.hibernate.impl.SessionImpl.list(SessionImpl.java:1148)

root cause

java.sql.SQLException: Io exception: The Network Adapter could not establish the connection
    oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112)
    oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:146)
    oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:255)
    oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:387)
    oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:414)
    oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:165)
    oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:35)
    oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:801)
    org.jboss.resource.adapter.jdbc.local.LocalManagedConnectionFactory.getLocalManagedConnection(LocalManagedConnectionFactory.java:207)
    org.jboss.resource.adapter.jdbc.local.LocalManagedConnectionFactory.createManagedConnection(LocalManagedConnectionFactory.java:195)
    org.jboss.resource.connectionmanager.InternalManagedConnectionPool.createConnectionEventListener(InternalManagedConnectionPool.java:633)
    org.jboss.resource.connectionmanager.InternalManagedConnectionPool.getConnection(InternalManagedConnectionPool.java:267)
    org.jboss.resource.connectionmanager.JBossManagedConnectionPool$BasePool.getConnection(JBossManagedConnectionPool.java:622)
    org.jboss.resource.connectionmanager.BaseConnectionManager2.getManagedConnection(BaseConnectionManager2.java:404)
    org.jboss.resource.connectionmanager.TxConnectionManager.getManagedConnection(TxConnectionManager.java:381)
    org.jboss.resource.connectionmanager.BaseConnectionManager2.allocateConnection(BaseConnectionManager2.java:496)
    org.jboss.resource.connectionmanager.BaseConnectionManager2$ConnectionManagerProxy.allocateConnection(BaseConnectionManager2.java:941)
    org.jboss.resource.adapter.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:89)
    org.hibernate.ejb.connection.InjectedDataSourceConnectionProvider.getConnection(InjectedDataSourceConnectionProvider.java:46)
    org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:446)
    org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:167)
    org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:161)
    org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1573)
    org.hibernate.loader.Loader.doQuery(Loader.java:696)
    org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:259)
    org.hibernate.loader.Loader.doList(Loader.java:2228)
    org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2125)
    org.hibernate.loader.Loader.list(Loader.java:2120)
    org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:401)
    org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:361)
    org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:196)
    org.hibernate.impl.SessionImpl.list(SessionImpl.java:1148)
    org.hibernate.impl.QueryImpl.list(QueryImpl.java:102)
    org.hibernate.ejb.QueryImpl.getResultList(QueryImpl.java:67)
    gov.medicaid.services.impl.RegistrationServiceBean.findByUsername(RegistrationServiceBean.java:156)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

note The full stack trace of the root cause is available in the JBoss Web/2.1.3.GA logs.

JBoss Web/2.1.3.GA

Answer 1

The issue here is:

org.jboss.resource.JBossResourceException: Could not create connection; - nested throwable: (java.sql.SQLException: Io exception: The Network Adapter could not establish the connection)

This generally means that you had database connection failure either due to database server being unavailable or an underlying network issue between your jboss server and the database server.

Answer 2

问题是你如何声明你的数据库配置，jdbc，url，用户，传递，驱动...因此服务器拒绝连接...

Answer 3

Kindly check your JBoss Server Configuration file in which you can find 'InUSeConnectionCount' which would be same as 'MaxConnectionPoolSize'. If this happens, this means that all your connections are used up and no connection is currently present which can process your request. Kindly flush your connection pool and try again. It will surely work :).

Answer 4

Generally this problem can appear, when your query preparation went wrong ie, when you are constructing the query programatically by concatenating strings of wrong datatypes (or) Database is down (or) if query failed execution with some exception then we used to get GenericJDBCException. First try to check your connection later verify whether your prepared query is correct or not. Alternately you can run the query in database client if its possible. Cheers...