クラシックJ2EEアーキテクチャーからの脱却

import javax.persistence.*;
...

@Entity
public class Customer {
  private Integer id;
  private String name;
  Set<Order> orders = new HashSet<Order>();
  
  @Id(generate=GeneratorType.AUTO)    
  public Integer getId() {
      return id;
  }
  public void setId(int id) {
      this.id = id;
  }
  public String getName() {
      return name;
  }
  public void setName(String name) {
      this.name = name;
  }

  @OneToMany(mappedBy="customer", cascade=CascadeType.ALL,
             fetch=FetchType.EAGER)
  public Set<Order> getOrders() {
      return orders;
  }
  
  public void setOrders(Set<Order> orders) {
      this.orders = orders;
  }

public class AppServiceImpl implements AppService {
  CustomerDao customerDao = new CustomerDaoImpl();
  ....

public class AppServiceImpl implements AppService {
  CustomerDao customerDao = AdHocFactory.getCustomerDao();
  ....

public class AppServiceImpl implements AppService {
  CustomerDao customerDao;
  ....
  public void setCustomerDao(CustomerDao customerDao) {
      this.customerDao = customerDao;
  }

DataSource dataSource = .....;
SessionFactory sessionFactory = .... // dataSourceを使用;

CustomerDaoImpl customerDao = new CustomerDaoImpl();
customerDao.setSessionFactory(sessionFactory);

OrderDaoImpl orderDao = new OrderDaoImpl();
orderDao.setSessionFactory(sessionFactory);

AppServiceImpl appServiceTarget = new AppServiceImpl();
appServiceTarget.setCustomerDao(customerDao);
appServiceTarget.setOrderDao(orderDao);

<beans>
  <bean id="myDataSource"
        class="org.apache.commons.dbcp.BasicDataSource" 
        destroy-method="close">
      <property name="driverClassName" 
                value="org.hsqldb.jdbcDriver"/>
      ...
  </bean>

  <bean id="mySessionFactory"
        class=".....AnnotationSessionFactoryBean">
      ....
      <property name="dataSource" ref="myDataSource"/>
      ....
  </bean>

  <bean id="myAbstractDao" abstract="true">
      <property name="sessionFactory" ref="mySessionFactory"/>
  </bean>

  <bean id="myCustomerDao" 
        class="com.example.CustomerDaoImpl"
        parent="myAbstractDao"/>

  <bean id="myOrderDao" class="com.example.OrderDaoImpl"
        parent="myAbstractDao"/>

  <bean id="myAppServiceTarget" 
        class="com.example.AppServiceImpl">
      <property name="customerDao" ref="myCustomerDao"/>
      <property name="orderDao" ref="myOrderDao"/>
  </bean>

<beans>

  <bean id="myTxManager" 
        class="org.springframework.orm.hibernate3.
               HibernateTransactionManager">
      <property name="sessionFactory" ref="mySessionFactory"/>
  </bean>

  <bean id="myAppService" 
        class="org.springframework.transaction.interceptor.
               TransactionProxyFactoryBean">
      <property name="transactionManager" ref="myTxManager"/>
      <property name="target" ref="myAppServiceTarget"/>

      <property name="transactionAttributes">
          <props>
              <prop key="*">PROPAGATION_REQUIRED</prop>
          </props>
      </property>

  </bean>

ApplicationContext context = ...
AppService appService = (AppService) context.getBean("myAppService");
// call business logic
....