[FIXED] JPA: java.lang.IllegalArgumentException: Not an entity

Issue

I wrote a simple Java that uses POJOs, servlets, JSPs. I am using:

• Tomcat 7.0.16
• Oracle 11g
• Oracle Java build 1.6.0_26-b03

I use ivy to resolve my dependencies:

    <dependency org="oracle" name="ojdbc6" rev="11g" conf="default -> default" />

    <dependency org="org.hibernate" name="hibernate-commons-annotations" rev="3.2.0.Final" conf="compile -> runtime" />
    <dependency org="org.hibernate" name="hibernate-annotations" rev="3.5.6-Final" conf="default -> runtime" />
    <dependency org="org.hibernate" name="hibernate-core" rev="3.6.5.Final" conf="default -> runtime" />
    <dependency org="org.hibernate" name="hibernate-validator" rev="4.0.2.GA" conf="runtime -> runtime" />
    <dependency org="org.hibernate.javax.persistence" name="hibernate-jpa-2.0-api" rev="1.0.1.Final" conf="compile -> default" />
    <dependency org="org.hibernate" name="hibernate-entitymanager" rev="3.6.5.Final" conf="compile -> default" />

My POJO Vehicle contains the following annotations:

import java.io.Serializable;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Version;

@Entity
public class Vehicle implements Serializable{


    /**
     * 
     */
    private static final long serialVersionUID = 8560417193012227968L;

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private Long identifier;

    private String serialNumber;
    private String model;
    private String manufacturer;
    private int year;
    private String condition;

    @Version
    private long version;

    public Vehicle(){
    }

When I run my code, I get the following:

2013-10-28 11:40:50 ERROR SqlVehicleService:42 - java.lang.IllegalArgumentException: Not an entity: class com.foo.demos.car.model.Vehicle
java.lang.IllegalArgumentException: Not an entity: class com.foo.demos.car.model.Vehicle
    at org.hibernate.ejb.metamodel.MetamodelImpl.entity(MetamodelImpl.java:160)
    at org.hibernate.ejb.criteria.QueryStructure.from(QueryStructure.java:138)
    at org.hibernate.ejb.criteria.CriteriaQueryImpl.from(CriteriaQueryImpl.java:179)
    at com.foo.demos.car.impl.SqlVehicleService.getVehicles(SqlVehicleService.java:37)
    at org.apache.jsp.secured.vehicles_jsp._jspService(vehicles_jsp.java:194)
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:419)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:389)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:333)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:572)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:563)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:403)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:301)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:162)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:309)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:662)

My persistence.xml does not contain any information about Vehicle. My understanding is that annotations are enough. Is that correct?

<?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"
 xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"
 version="1.0">

 <persistence-unit name="cardemo">
  <provider>org.hibernate.ejb.HibernatePersistence</provider>
  <!-- the JNDI data source -->
  <non-jta-data-source>java:comp/env/jdbc/cardemo</non-jta-data-source>
  <properties>
 <property name="javax.persistence.validation.mode" value="NONE" />
   <!-- if this is true, hibernate will print (to stdout) the SQL it executes, 
    so you can check it to ensure it"s not doing anything crazy -->
   <property name="hibernate.show_sql" value="true" />
   <property name="hibernate.format_sql" value="true" />
   <!-- since most database servers have slightly different versions of the 
    SQL, Hibernate needs you to choose a dialect so it knows the subtleties of 
    talking to that server -->
   <property name="hibernate.dialect" value="org.hibernate.dialect.Oracle10gDialect" />
   <!-- this tell Hibernate to update the DDL when it starts, very useful 
    for development, dangerous in production -->
   <property name="hibernate.hbm2ddl.auto" value="update" />
  </properties>
 </persistence-unit>
</persistence>

I obviously overlooked something. What's that? What am I missing?

Solution

My persistence.xml does not contain any information about Vehicle. My understanding is that annotations are enough. Is that correct?

No, it's not. The entities must be listed in the persistence.xml file, under the persistence-unit element:

<class>com.foo.demos.car.model.Vehicle</class>

Answered By - JB Nizet
Answer Checked By - Gilberto Lyons (JavaFixing Admin)