public abstract class Generic<T, ID extends Serializable> {
  private Class<T>        persistenceClass;
  private EntityManager em;

  @PersistenceContext
  public void setEntityManager(EntityManager em) {
    this.em = em;
  }
  public EntityManager getEntityManager() {
    return em;
  }
  public void save(T entity) {
    getEntityManager().persist(entity);
  }
  public void delete(T entity) {
    getEntityManager().remove(getEntityManager().merge(entity));
  }
  public T getById(Object id) {
    return(getEntityManager.find(persistenceClass, id));
  }
}

public interface GenericService<T> {
  T create(T entity);
  void delete(T entity);
  T update(T entity);
  T getById(Object id);
  List<T>  list(int page, int size);
}

public User create(User entity) {
  authorDAO.save(entity);
  return(entity);
}

public T findById(Object id) {
  return(getEntityManager().find(clazz, id));
}

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="
    http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
    http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd
    http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.0.xsd">

   <!--
      This is the BeanPostProcessor object that processes PersistenceUnit
      and PersistenceContext annotations, for injection of the corresponding
      JPA resources EntityManager and EntityManagerFactory.  Any SPring managed
      objects with these annotations will be injected.
      
      Did not see this referenced here
      http://www.springbyexample.org/examples/one-to-many-jpa-template-config.html
    -->
    <bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />
   
    <!-- Import -->
   <import resource="sampleappContext.xml"/>
   
   <!--
       Many references here have pointed to using 
       org.springframework.orm.hibernate3.LocalSessionFactoryBean
       
       But examples located here
       http://www.springbyexample.org/examples/one-to-many-jpa-template-config.html
       recommend that you use the LocalContainerEntityManagerFactoryBean object
       instead.
     -->
    <bean   id="entityManagerFactory"
           class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
           <property name="dataSource" ref="dataSource" />
           <!-- <property name="persistenceUnitName" value="simple-jpa-template"/> -->
           <property name="jpaVendorAdapter">
               <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
                      <property name="database" value="MYSQL" />
                      <!-- <property name="database" value="SQL_SERVER" /> -->
                      <property name="showSql" value="true" />
                      <property name="generateDdl" value="true" />
               </bean>
           </property>
    </bean>
   
   <!--  Local MySQL Installation -->
    <bean id="dataSource"
        class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver" />
        <property name="url" value="jdbc:mysql://localhost:3308/sampleapp2" />
        <property name="username" value="root" />
        <property name="password" value="w3bl0g1c" />
    </bean>       
     
   <!--
      Some examples have shown for the transactionManager to reference class
      org.springframework.orm.hibernate3.HibernateTransactionManager
      
      But it appears that JPA/Hibernate have been integrated and the following
      definition is expected for this framework to work.
    -->
   <bean    id="transactionManager"
         class="org.springframework.orm.jpa.JpaTransactionManager">
         <property name="entityManagerFactory" ref="entityManagerFactory" />
   </bean>
           
   
   <!--  Defines our transaction manager for transaction annotated objects -->
   <tx:annotation-driven transaction-manager="transactionManager" />
   
</beans>