Cannot open connection exception: JDBC general exception

Question

I thought I was getting this error because I did not have ojdbc14.jar deployed inside / common / lib. The question still remains even after I did this.

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 problem is here:

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

This usually means that your database connection failed due to inaccessibility of the database server or a major network problem between the jboss server and the database server.

Answer 2

the problem is how you declare your configuration db, jdbc, url, user, pass, driver ... for this reason the server refuses to connect ...

Answer 3

Please check the JBoss server configuration file, in which you can find "InUSeConnectionCount", which will be the same as "MaxConnectionPoolSize". If this happens, it means that all your connections are exhausted and there is currently no connection that can handle your request. Please flush your connection pool and try again. This will certainly work :).

Answer 4

As a rule, this problem may appear when your preparation of the request went wrong, i.e. when you randomly create a query by combining rows of incorrect data types (or) The database does not work (or), if the query fails with some exception, then we used to get a GenericJDBCException. First try to check your connection, then check whether the prepared request is correct or not. Alternatively, you can run the query in the database client, if possible. Greetings ...