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>
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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!!!");
}
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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)
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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
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javax.faces.FacesException: java.lang.InstantiationException: Some objects
to be injected were not found in jndi: [javax.naming.NotContextException:
sample.jpa.currency.CurrencyUtil/em]
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How do we get the proper EntityManager Instance in the web application??
Thanks in advance!!
Phani
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