title: Predeployment of PersistenceUnit failed with EclipseLink
body: <p>Am new to JPA and starting out with EclipseLink. Taking help from tutorial I started creating my first JPA project consiting of an Entity (automatically created using JPA tools), a simple main class firing the most basic select query. However when i try running the main class I get a Predeployment of PersistenceUnit failed exception. Am using SQL server express 2008 and querying sample AdventureWorks database. Am able to connect to database (using Database Development Perspective). Detailed error log and Code snippets below:</p>
  
  <p><strong>Main class</strong></p>
  
  <pre><code>    import java.util.List;
      import javax.persistence.EntityManager;
      import javax.persistence.Persistence;
      import model.Employee;
  
      public class Main {
      public static void main(String[] args) {
  EntityManager em =    Persistence.createEntityManagerFactory("JPA2").createEntityManager();
      List&lt;Employee&gt; list = em.createQuery("Select * from humanresources.Employee", Employee.class).getResultList();
      for(Employee e : list)
      {
          System.out.println(e.getBirthDate());
      }
  }
   }
  </code></pre>
  
  <p><strong>Entity</strong></p>
  
  <pre><code>         package model;
  
           import java.io.Serializable;
           import javax.persistence.*;
           import java.sql.Timestamp;
  
          @Entity
          public class Employee implements Serializable { 
      private static final long serialVersionUID = 1L;
  
      @Id 
          @Column(name="BusinessEntityID")
      private int businessEntityID;
  
      @Column(name="BirthDate")
      private Object birthDate;
  
      @Column(name="Gender")
      private Object gender; 
  
      @Column(name="HireDate")
      private Object hireDate;
  
      @Column(name="JobTitle")
      private Object jobTitle;
  
    @Column(name="MaritalStatus");
      private Object maritalStatus;
  
  @Column(name="ModifiedDate")
  private Timestamp modifiedDate;
  
  @Column(name="NationalIDNumber")
  private Object nationalIDNumber;
  
  @Column(name="OrganizationLevel")
  private short organizationLevel;
  
  @Column(name="OrganizationNode")
  private String organizationNode;
  
  private String rowguid;
  
  @Column(name="SickLeaveHours")
  private short sickLeaveHours;
  
  @Column(name="VacationHours")
  private short vacationHours;
  
  public Employee() {
  }
  
  public int getBusinessEntityID() {
      return this.businessEntityID;
  }
  
  public void setBusinessEntityID(int businessEntityID) {
      this.businessEntityID = businessEntityID;
  }
  
  public Object getBirthDate() {
      return this.birthDate;
  }
  
  public void setBirthDate(Object birthDate) {
      this.birthDate = birthDate;
  }
  
  public Object getGender() {
      return this.gender;
  }
  
  public void setGender(Object gender) {
      this.gender = gender;
  }
  
  public Object getHireDate() {
      return this.hireDate;
  }
  
  public void setHireDate(Object hireDate) {
      this.hireDate = hireDate;
  }
  
  public Object getJobTitle() {
      return this.jobTitle;
  }
  
  public void setJobTitle(Object jobTitle) {
      this.jobTitle = jobTitle;
  }
  
  
  public Object getMaritalStatus() {
      return this.maritalStatus;
  }
  
  public void setMaritalStatus(Object maritalStatus) {
      this.maritalStatus = maritalStatus;
  }
  
  public Timestamp getModifiedDate() {
      return this.modifiedDate;
  }
  
  public void setModifiedDate(Timestamp modifiedDate) {
      this.modifiedDate = modifiedDate;
  }
  
  public Object getNationalIDNumber() {
      return this.nationalIDNumber;
  }
  
  public void setNationalIDNumber(Object nationalIDNumber) {
      this.nationalIDNumber = nationalIDNumber;
  }
  
  public short getOrganizationLevel() {
      return this.organizationLevel;
  }
  
  public void setOrganizationLevel(short organizationLevel) {
      this.organizationLevel = organizationLevel;
  }
  
  public String getOrganizationNode() {
      return this.organizationNode;
  }
  
  public void setOrganizationNode(String organizationNode) {
      this.organizationNode = organizationNode;
  }
  
  public String getRowguid() {
      return this.rowguid;
  }
  
  public void setRowguid(String rowguid) {
      this.rowguid = rowguid;
  }
  
  public short getSickLeaveHours() {
      return this.sickLeaveHours;
  }
  
  public void setSickLeaveHours(short sickLeaveHours) {
      this.sickLeaveHours = sickLeaveHours;
  }
  
  public short getVacationHours() {
      return this.vacationHours;
  }
  
  public void setVacationHours(short vacationHours) {
      this.vacationHours = vacationHours;
  }
  
   }
  </code></pre>
  
  <p><strong>Persistence.XML (under Meta-INF folder)</strong></p>
  
  <pre><code>       &lt;?xml version="1.0" encoding="UTF-8"?&gt;
         &lt;persistence version="2.0" 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_2_0.xsd"&gt;
  &lt;persistence-unit name="JPA2" transaction-type="RESOURCE_LOCAL"&gt;
      &lt;provider&gt;org.eclipse.persistence.jpa.PersistenceProvider&lt;/provider&gt;
      &lt;class&gt;model.Employee&lt;/class&gt;
      &lt;properties&gt;
          &lt;property name="eclipselink.target-database" value="SQLServer"/&gt;
          &lt;property name="javax.persistence.jdbc.url" value="jdbc:sqlserver://localhost:1433;databaseName=AdventureWorks2008"/&gt;
          &lt;property name="javax.persistence.jdbc.user" value="Username"/&gt;
          &lt;property name="javax.persistence.jdbc.password" value="Username"/&gt;
          &lt;property name="javax.persistence.jdbc.driver" value="com.microsoft.sqlserver.jdbc.SQLServerDriver"/&gt;
      &lt;/properties&gt;
  &lt;/persistence-unit&gt;
  </code></pre>
  
  <p></p>
  
  <p><strong>Exception</strong></p>
  
  <pre><code>Exception in thread "main" Local Exception Stack: 
             Exception [EclipseLink-30005] (Eclipse Persistence Services - 2.4.2.v20130514-                  5956486): org.eclipse.persistence.exceptions.PersistenceUnitLoadingException
             Exception Description: An exception was thrown while searching for persistence        archives with ClassLoader: sun.misc.Launcher$AppClassLoader@1ac04e8
             Internal Exception: javax.persistence.PersistenceException: Exception   [EclipseLink-28018] (Eclipse Persistence Services - 2.4.2.v20130514-5956486):          org.eclipse.persistence.exceptions.EntityManagerSetupException
             Exception Description: Predeployment of PersistenceUnit [JPA2] failed.
             Internal Exception: Exception [EclipseLink-7155] (Eclipse Persistence Services -  2.4.2.v20130514-5956486): org.eclipse.persistence.exceptions.ValidationException
             Exception Description: The type [class java.lang.Object] for the attribute  [hireDate] on the entity class [class model.Employee] is not a valid type for a serialized  mapping. The attribute type must implement the Serializable interface.
              at   org.eclipse.persistence.exceptions.PersistenceUnitLoadingException.exceptionSearchingForPer sistenceResources(PersistenceUnitLoadingException.java:127)
              at  org.eclipse.persistence.jpa.PersistenceProvider.createEntityManagerFactory(PersistenceProvi der.java:118)
              at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:78)
      at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:54)
      at Main.main(Main.java:20)
             Caused by: javax.persistence.PersistenceException: Exception [EclipseLink-28018]  (Eclipse Persistence Services - 2.4.2.v20130514-5956486):  org.eclipse.persistence.exceptions.EntityManagerSetupException
             Exception Description: Predeployment of PersistenceUnit [JPA2] failed.
             Internal Exception: Exception [EclipseLink-7155] (Eclipse Persistence Services -  2.4.2.v20130514-5956486): org.eclipse.persistence.exceptions.ValidationException
             Exception Description: The type [class java.lang.Object] for the attribute   [hireDate] on the entity class [class model.Employee] is not a valid type for a serialized  mapping. The attribute type must implement the Serializable interface.
              at  org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.createPredeployFailedPersistenc eException(EntityManagerSetupImpl.java:1556)
              at  org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.predeploy(EntityManagerSetupImp l.java:1547)
              at  org.eclipse.persistence.internal.jpa.deployment.JPAInitializer.callPredeploy(JPAInitializer .java:98)
              at  org.eclipse.persistence.jpa.PersistenceProvider.createEntityManagerFactory(PersistenceProvi der.java:108)
      ... 3 more
             Caused by: Exception [EclipseLink-28018] (Eclipse Persistence Services -  2.4.2.v20130514-5956486): org.eclipse.persistence.exceptions.EntityManagerSetupException
             Exception Description: Predeployment of PersistenceUnit [JPA2] failed.
             Internal Exception: Exception [EclipseLink-7155] (Eclipse Persistence Services -             2.4.2.v20130514-5956486): org.eclipse.persistence.exceptions.ValidationException
             Exception Description: The type [class java.lang.Object] for the attribute  [hireDate] on the entity class [class model.Employee] is not a valid type for a serialized   mapping. The attribute type must implement the Serializable interface.
              at  org.eclipse.persistence.exceptions.EntityManagerSetupException.predeployFailed(EntityManage rSetupException.java:221)
                  ... 7 more
             Caused by: Exception [EclipseLink-7155] (Eclipse Persistence Services -  2.4.2.v20130514-5956486): org.eclipse.persistence.exceptions.ValidationException
             Exception Description: The type [class java.lang.Object] for the attribute  [hireDate] on the entity class [class model.Employee] is not a valid type for a serialized mapping. The attribute type must implement the Serializable interface.
              at  org.eclipse.persistence.exceptions.ValidationException.invalidTypeForSerializedAttribute(ValidationException.java:1121)
      at org.eclipse.persistence.internal.jpa.metadata.converters.SerializedMetadata.process(SerializedMetadata.java:99)
      at org.eclipse.persistence.internal.jpa.metadata.accessors.mappings.MappingAccessor.processSerialized(MappingAccessor.java:1807)
      at org.eclipse.persistence.internal.jpa.metadata.accessors.mappings.MappingAccessor.processJPA Converters(MappingAccessor.java:1586)
      at org.eclipse.persistence.internal.jpa.metadata.accessors.mappings.MappingAccessor.processMappingConverter(MappingAccessor.java:1652)
      at org.eclipse.persistence.internal.jpa.metadata.accessors.mappings.MappingAccessor.processMap pingValueConverter(MappingAccessor.java:1670)
      at org.eclipse.persistence.internal.jpa.metadata.accessors.mappings.BasicAccessor.process(BasicAccessor.java:414)
      at org.eclipse.persistence.internal.jpa.metadata.MetadataDescriptor.processMappingAccessors(MetadataDescriptor.java:1461)
      at org.eclipse.persistence.internal.jpa.metadata.accessors.classes.ClassAccessor.processMappingAccessors(ClassAccessor.java:1526)
      at org.eclipse.persistence.internal.jpa.metadata.accessors.classes.EntityAccessor.processMappingAccessors(EntityAccessor.java:1085)
      at org.eclipse.persistence.internal.jpa.metadata.accessors.classes.EntityAccessor.process(EntityAccessor.java:645)
      at org.eclipse.persistence.internal.jpa.metadata.MetadataProject.processStage2(MetadataProject.java:1718)
      at org.eclipse.persistence.internal.jpa.metadata.MetadataProcessor.processORMMetadata(MetadataProcessor.java:536)
      at org.eclipse.persistence.internal.jpa.deployment.PersistenceUnitProcessor.processORMetadata(PersistenceUnitProcessor.java:550)
      at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.predeploy(EntityManagerSetupImpl.java:1484)
      ... 5 more
  </code></pre>