Hi, I was trying to obtain javax.persistence.EntityManager in a web application as follows.
1. Created persistence.xml in META-INF folder. __________________ <?xml version="1.0" encoding="UTF-8"?> <persistence xmlns="http://java.sun.com/xml/ns/persistence"; xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"; version="1.0" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd";> <persistence-unit name="CurrencyRateUnit"> <description>JPA JSF Sample</description> <provider>org.apache.openjpa.persistence.PersistenceProviderImpl</provider> <class>sample.jpa.currency.Currency</class> <properties> <property name="openjpa.ConnectionURL" value="jdbc:derby:CurrencyDB" /> <property name="openjpa.ConnectionDriverName" value="org.apache.derby.jdbc.EmbeddedDriver" /> <property name="ConnectionUserName" value="app" /> <property name="openjpa.jdbc.SynchronizeMappings" value="false" /> </properties> </persistence-unit> </persistence> ______________________________________________________________________ 2. I have a utility class in the web application which tries to obtain EntityManager as follows. ________________ public class CurrencyUtil { //@PersistenceContext(unitName="CurrencyRateUnit") private EntityManager em; private Collection currencies; public CurrencyUtil() { EntityManagerFactory emf = Persistence.createEntityManagerFactory("CurrencyRateUnit"); if(emf == null) System.out.println("emf is null!!!"); em = emf.createEntityManager(); if(em == null) System.out.println("em is null!!!"); } ________________________________________ I have also tried with the above code in a servlet. In all the cases I get the following error. __________________________________________________________________________________________ 18:02:36,328 ERROR [[Test]] Servlet.service() for servlet Test threw exception <openjpa-1.0.1-r420667:592145 fatal user error> org.apache.openjpa.persistence.ArgumentException: A JDBC Driver or DataSource class name must be specified in the ConnectionDriverName property. at org.apache.openjpa.jdbc.schema.DataSourceFactory.newDataSource(DataSourceFactory.java:72) at org.apache.openjpa.jdbc.conf.JDBCConfigurationImpl.createConnectionFactory(JDBCConfigurationImpl.java:803) at org.apache.openjpa.jdbc.conf.JDBCConfigurationImpl.getDBDictionaryInstance(JDBCConfigurationImpl.java:568) at org.apache.openjpa.jdbc.meta.MappingRepository.endConfiguration(MappingRepository.java:1221) at org.apache.openjpa.lib.conf.Configurations.configureInstance(Configurations.java:476) at org.apache.openjpa.lib.conf.Configurations.configureInstance(Configurations.java:401) at org.apache.openjpa.lib.conf.PluginValue.instantiate(PluginValue.java:102) at org.apache.openjpa.lib.conf.ObjectValue.instantiate(ObjectValue.java:82) at org.apache.openjpa.conf.OpenJPAConfigurationImpl.newMetaDataRepositoryInstance(OpenJPAConfigurationImpl.java:861) at org.apache.openjpa.conf.OpenJPAConfigurationImpl.getMetaDataRepositoryInstance(OpenJPAConfigurationImpl.java:852) at org.apache.openjpa.kernel.AbstractBrokerFactory.makeReadOnly(AbstractBrokerFactory.java:630) at org.apache.openjpa.kernel.AbstractBrokerFactory.newBroker(AbstractBrokerFactory.java:169) at org.apache.openjpa.kernel.DelegatingBrokerFactory.newBroker(DelegatingBrokerFactory.java:142) at org.apache.openjpa.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:192) at org.apache.openjpa.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:145) at org.apache.openjpa.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:56) at sample.jpa.currency.Test.doGet(Test.java:33) at javax.servlet.http.HttpServlet.service(HttpServlet.java:693) at javax.servlet.http.HttpServlet.service(HttpServlet.java:806) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175) at org.apache.geronimo.tomcat.valve.DefaultSubjectValve.invoke(DefaultSubjectValve.java:56) at org.apache.geronimo.tomcat.GeronimoStandardContext$SystemMethodValve.invoke(GeronimoStandardContext.java:406) at org.apache.geronimo.tomcat.valve.GeronimoBeforeAfterValve.invoke(GeronimoBeforeAfterValve.java:47) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128) at org.apache.catalina.ha.session.JvmRouteBinderValve.invoke(JvmRouteBinderValve.java:209) at org.apache.catalina.ha.tcp.ReplicationValve.invoke(ReplicationValve.java:347) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:563) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:263) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:584) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447) at java.lang.Thread.run(Thread.java:803) _______________________________________________________________________________________________ Looks like, JPA is not able to find persistence.xml and read the value of "ConnectionDriverName" property. I have also tried to use @PersistenceContext(unitName="CurrencyRateUnit") annotation but failed. It throws the below exception ____________________ javax.faces.FacesException: java.lang.InstantiationException: Some objects to be injected were not found in jndi: [javax.naming.NotContextException: sample.jpa.currency.CurrencyUtil/em] _________________________ How do we get the proper EntityManager Instance in the web application?? Thanks in advance!! Phani
