Monday, 25 July 2011

Error: PersistenceExceptionorg.hibernate.exception.GenericJDBCException: Cannot open connection

This problem has been causing me headaches, lately. After some heavy googling, I came across the following explanation.

The biggest problem here is that at first glance in my stacktrace it totally looked like a transaction/sqlserver problem.

Here's the stacktrace:

2011-07-23 22:23:46,805 WARN [org.hibernate.util.JDBCExceptionReporter] [ ] SQL Error: 0, SQLState: null 2011-07-23 22:23:46,805 ERROR [org.hibernate.util.JDBCExceptionReporter] [ ] Transaction is not active: tx=TransactionImple < ac, BasicAction: 53f73f9b:8b5:4e26e1da:501d3a status: ActionStatus.ABORT_ONLY >; - nested throwable: (javax.resource.ResourceException: Transaction is not active: tx=TransactionImple < ac, BasicAction: 53f73f9b:8b5:4e26e1da:501d3a status: ActionStatus.ABORT_ONLY >) 2011-07-23 22:23:46,805 ERROR [nl.isaac.youw8.ejb.StorageServiceBean] [ ] Error: PersistenceExceptionorg.hibernate.exception.GenericJDBCException: Cannot open connection searching an DashboardUser Query: from DashboardUser WHERE id = :id ORDER BY ID DESC javax.persistence.PersistenceException: org.hibernate.exception.GenericJDBCException: Cannot open connection at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:629) at org.hibernate.ejb.QueryImpl.getSingleResult(QueryImpl.java:99) at nl.isaac.youw8.ejb.StorageServiceBean.findSingle(StorageServiceBean.java:673) at nl.isaac.youw8.ejb.StorageServiceBean.findSingleObjectLike(StorageServiceBean.java:136) at sun.reflect.GeneratedMethodAccessor778.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:112) at org.jboss.ejb3.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:166) at youw8.interceptors.DefaultInterceptor.intercept(DefaultInterceptor.java:140) at sun.reflect.GeneratedMethodAccessor220.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.jboss.ejb3.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:118) at org.jboss.ejb3.interceptor.EJB3InterceptorsInterceptor.invoke(EJB3InterceptorsInterceptor.java:63) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.entity.TransactionScopedEntityManagerInterceptor.invoke(TransactionScopedEntityManagerInterceptor.java:54) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.AllowedOperationsInterceptor.invoke(AllowedOperationsInterceptor.java:47) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.tx.TxPolicy.invokeInCallerTx(TxPolicy.java:126) at org.jboss.aspects.tx.TxInterceptor$Required.invoke(TxInterceptor.java:195) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.tx.TxPropagationInterceptor.invoke(TxPropagationInterceptor.java:95) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.stateless.StatelessInstanceInterceptor.invoke(StatelessInstanceInterceptor.java:62) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.security.RoleBasedAuthorizationInterceptor.invoke(RoleBasedAuthorizationInterceptor.java:166) at org.jboss.ejb3.security.RoleBasedAuthorizationInterceptor.invoke(RoleBasedAuthorizationInterceptor.java:115) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.security.AuthenticationInterceptor.invoke(AuthenticationInterceptor.java:77) at org.jboss.ejb3.security.Ejb3AuthenticationInterceptor.invoke(Ejb3AuthenticationInterceptor.java:110) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.ENCPropagationInterceptor.invoke(ENCPropagationInterceptor.java:46) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.asynchronous.AsynchronousInterceptor.invoke(AsynchronousInterceptor.java:106) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.stateless.StatelessContainer.localInvoke(StatelessContainer.java:240) at org.jboss.ejb3.stateless.StatelessContainer.localInvoke(StatelessContainer.java:210) at org.jboss.ejb3.stateless.StatelessLocalProxy.invoke(StatelessLocalProxy.java:84) at $Proxy157.findSingleObjectLike(Unknown Source) at youw8.services.exposed.webservices.rest.MeasurementsResource.addActivityMeasurement(MeasurementsResource.java:486) at sun.reflect.GeneratedMethodAccessor1608.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$ResponseOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:184) at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:67) at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:276) at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:133) at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:83) at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:133) at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:71) at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1171) at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1103) at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1053) at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1043) at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:406) at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:477) at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:662) at javax.servlet.http.HttpServlet.service(HttpServlet.java:803) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at youw8.services.exposed.oauth.provider.servlets.AuthorizationServlet.doFilter(AuthorizationServlet.java:259) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175) at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:182) at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:262) at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:856) at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:566) at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1508) at java.lang.Thread.run(Thread.java:619) Caused by: org.hibernate.exception.GenericJDBCException: Cannot open connection at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:103) at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:91) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:29) at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:426) at org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:144) at org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:139) at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1547) at org.hibernate.loader.Loader.doQuery(Loader.java:673) at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:236) at org.hibernate.loader.Loader.doList(Loader.java:2220) at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2104) at org.hibernate.loader.Loader.list(Loader.java:2099) at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:378) at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:338) at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:172) at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1121) at org.hibernate.impl.QueryImpl.list(QueryImpl.java:79) at org.hibernate.ejb.QueryImpl.getSingleResult(QueryImpl.java:80) ... 75 more Caused by: org.jboss.util.NestedSQLException: Transaction is not active: tx=TransactionImple < ac, BasicAction: 53f73f9b:8b5:4e26e1da:501d3a status: ActionStatus.ABORT_ONLY >; - nested throwable: (javax.resource.ResourceException: Transaction is not active: tx=TransactionImple < ac, BasicAction: 53f73f9b:8b5:4e26e1da:501d3a status: ActionStatus.ABORT_ONLY >) at org.jboss.resource.adapter.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:95) at org.hibernate.ejb.connection.InjectedDataSourceConnectionProvider.getConnection(InjectedDataSourceConnectionProvider.java:47) at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:423) ... 89 more Caused by: javax.resource.ResourceException: Transaction is not active: tx=TransactionImple < ac, BasicAction: 53f73f9b:8b5:4e26e1da:501d3a status: ActionStatus.ABORT_ONLY > at org.jboss.resource.connectionmanager.TxConnectionManager.getManagedConnection(TxConnectionManager.java:319) at org.jboss.resource.connectionmanager.BaseConnectionManager2.allocateConnection(BaseConnectionManager2.java:402) at org.jboss.resource.connectionmanager.BaseConnectionManager2$ConnectionManagerProxy.allocateConnection(BaseConnectionManager2.java:849) at org.jboss.resource.adapter.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:89) ... 91 more 2011-07-23 22:23:46,805 WARN [org.hibernate.util.JDBCExceptionReporter] [ ] SQL Error: 0, SQLState: null 2011-07-23 22:23:46,805 ERROR [org.hibernate.util.JDBCExceptionReporter] [ ] Transaction is not active: tx=TransactionImple < ac, BasicAction: 53f73f9b:8b5:4e26e1da:501d3a status: ActionStatus.ABORT_ONLY >; - nested throwable: (javax.resource.ResourceException: Transaction is not active: tx=TransactionImple < ac, BasicAction: 53f73f9b:8b5:4e26e1da:501d3a status: ActionStatus.ABORT_ONLY >) 2011-07-23 22:23:46,805 ERROR [nl.isaac.youw8.ejb.StorageServiceBean] [ ] Error: PersistenceExceptionorg.hibernate.exception.GenericJDBCException: Cannot open connection searching an Activity Query: from Activity WHERE id = :id ORDER BY ID DESC javax.persistence.PersistenceException: org.hibernate.exception.GenericJDBCException: Cannot open connection at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:629) at org.hibernate.ejb.QueryImpl.getSingleResult(QueryImpl.java:99) at nl.isaac.youw8.ejb.StorageServiceBean.findSingle(StorageServiceBean.java:673) at nl.isaac.youw8.ejb.StorageServiceBean.findSingleObjectLike(StorageServiceBean.java:136) at sun.reflect.GeneratedMethodAccessor778.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:112) at org.jboss.ejb3.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:166) at youw8.interceptors.DefaultInterceptor.intercept(DefaultInterceptor.java:140) at sun.reflect.GeneratedMethodAccessor220.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.jboss.ejb3.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:118) at org.jboss.ejb3.interceptor.EJB3InterceptorsInterceptor.invoke(EJB3InterceptorsInterceptor.java:63) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.entity.TransactionScopedEntityManagerInterceptor.invoke(TransactionScopedEntityManagerInterceptor.java:54) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.AllowedOperationsInterceptor.invoke(AllowedOperationsInterceptor.java:47) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.tx.TxPolicy.invokeInCallerTx(TxPolicy.java:126) at org.jboss.aspects.tx.TxInterceptor$Required.invoke(TxInterceptor.java:195) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.tx.TxPropagationInterceptor.invoke(TxPropagationInterceptor.java:95) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.stateless.StatelessInstanceInterceptor.invoke(StatelessInstanceInterceptor.java:62) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.security.RoleBasedAuthorizationInterceptor.invoke(RoleBasedAuthorizationInterceptor.java:166) at org.jboss.ejb3.security.RoleBasedAuthorizationInterceptor.invoke(RoleBasedAuthorizationInterceptor.java:115) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.security.AuthenticationInterceptor.invoke(AuthenticationInterceptor.java:77) at org.jboss.ejb3.security.Ejb3AuthenticationInterceptor.invoke(Ejb3AuthenticationInterceptor.java:110) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.ENCPropagationInterceptor.invoke(ENCPropagationInterceptor.java:46) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.asynchronous.AsynchronousInterceptor.invoke(AsynchronousInterceptor.java:106) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.stateless.StatelessContainer.localInvoke(StatelessContainer.java:240) at org.jboss.ejb3.stateless.StatelessContainer.localInvoke(StatelessContainer.java:210) at org.jboss.ejb3.stateless.StatelessLocalProxy.invoke(StatelessLocalProxy.java:84) at $Proxy157.findSingleObjectLike(Unknown Source) at youw8.services.exposed.webservices.rest.MeasurementsResource.addActivityMeasurement(MeasurementsResource.java:490) at sun.reflect.GeneratedMethodAccessor1608.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$ResponseOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:184) at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:67) at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:276) at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:133) at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:83) at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:133) at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:71) at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1171) at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1103) at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1053) at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1043) at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:406) at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:477) at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:662) at javax.servlet.http.HttpServlet.service(HttpServlet.java:803) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at youw8.services.exposed.oauth.provider.servlets.AuthorizationServlet.doFilter(AuthorizationServlet.java:259) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175) at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:182) at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:262) at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:856) at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:566) at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1508) at java.lang.Thread.run(Thread.java:619) Caused by: org.hibernate.exception.GenericJDBCException: Cannot open connection at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:103) at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:91) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:29) at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:426) at org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:144) at org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:139) at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1547) at org.hibernate.loader.Loader.doQuery(Loader.java:673) at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:236) at org.hibernate.loader.Loader.doList(Loader.java:2220) at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2104) at org.hibernate.loader.Loader.list(Loader.java:2099) at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:378) at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:338) at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:172) at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1121) at org.hibernate.impl.QueryImpl.list(QueryImpl.java:79) at org.hibernate.ejb.QueryImpl.getSingleResult(QueryImpl.java:80) ... 75 more Caused by: org.jboss.util.NestedSQLException: Transaction is not active: tx=TransactionImple < ac, BasicAction: 53f73f9b:8b5:4e26e1da:501d3a status: ActionStatus.ABORT_ONLY >; - nested throwable: (javax.resource.ResourceException: Transaction is not active: tx=TransactionImple < ac, BasicAction: 53f73f9b:8b5:4e26e1da:501d3a status: ActionStatus.ABORT_ONLY >) at org.jboss.resource.adapter.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:95) at org.hibernate.ejb.connection.InjectedDataSourceConnectionProvider.getConnection(InjectedDataSourceConnectionProvider.java:47) at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:423) ... 89 more Caused by: javax.resource.ResourceException: Transaction is not active: tx=TransactionImple < ac, BasicAction: 53f73f9b:8b5:4e26e1da:501d3a status: ActionStatus.ABORT_ONLY > at org.jboss.resource.connectionmanager.TxConnectionManager.getManagedConnection(TxConnectionManager.java:319) at org.jboss.resource.connectionmanager.BaseConnectionManager2.allocateConnection(BaseConnectionManager2.java:402) at org.jboss.resource.connectionmanager.BaseConnectionManager2$ConnectionManagerProxy.allocateConnection(BaseConnectionManager2.java:849) at org.jboss.resource.adapter.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:89) ... 91 more 2011-07-23 22:23:46,805 ERROR [youw8.services.exposed.webservices.rest.MeasurementsResource] [ ] error occured:null

The important part in the stack trace is: org.hibernate.exception.SQLStateConverter.handledNonSpecificException. This indicates that an exception occurred that was not handled correctly and somewhere along the line the problem was caught, the transaction was rolled back, and then the rest of the business logic started performing without having any longer a transaction context.

At least, it's probably something like that.

It turned out to be a NullPointerException.

Friday, 22 July 2011

Senior Java Developer Test

Found the following test on http://thedailywtf.com. It tickled my fancy. An interesting use for recursion.

Question 1
(a) What does the following function do?
(b) How could the function be improved?
(c) Rewrite the function with your suggested improvements.
public String funcX (String s) {
  if (s == null || s.length() == 1 || s.length() == 0) {
    return s;
  } else {
    return funcX(s.substring(1)) + s.substring(0, 1);
  }
}

Just a small javadoc addendum to clarify things:

public String substring(int beginIndex, int endIndex)
Returns a new string that is a substring of this string. The substring begins at the specified beginIndex and extends to the character at index endIndex - 1. Thus the length of the substring is endIndex-beginIndex.