Spring整合JPA与Hibernate流程详解

/* applicationContext.xml */
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns=…>
  <!-- 配置属性文件的文件路径 -->
  <context:property-placeholder 
       location="classpath:jdbc.properties"/>
  <!-- 配置C3P0数据库连接池 -->
  <bean id="dataSource" 
     class="com.mchange.v2.c3p0.ComboPooledDataSource">
    <property name="jdbcUrl" value="${jdbc.url}"/>
    <property name="driverClass" value="${jdbc.driver.class}"/>
    <property name="user" value="${jdbc.username}"/>
    <property name="password" value="${jdbc.password}"/>
  </bean>
  <!-- Spring 整合 JPA，配置 EntityManagerFactory-->
  <bean id="entityManagerFactory"
      class="org.springframework.orm.jpa
             .LocalContainerEntityManagerFactoryBean">
     <property name="dataSource" ref="dataSource"/>
 
     <property name="jpaVendorAdapter">
        <bean class="org.springframework.orm.jpa.vendor
            .HibernateJpaVendorAdapter">
          <!-- Hibernate 相关的属性 -->
          <!-- 配置数据库类型 -->
         <property name="database" value="MYSQL"/>
         <!-- 显示执行的 SQL -->
         <property name="showSql" value="true"/>
      </bean>
    </property>
    <!-- 配置Spring所扫描的实体类所在的包 -->
    <property name="packagesToScan">
      <list>
        <value>mypack</value>
      </list>
    </property>
  </bean>
  <!-- 配置事务管理器 -->
  <bean id="transactionManager"
    class="org.springframework.orm.jpa.JpaTransactionManager">
    <property name="entityManagerFactory"
                      ref="entityManagerFactory"/>
   </bean>
   <bean id="CustomerService"  class="mypack.CustomerServiceImpl" />
   <bean id="CustomerDao"  class="mypack.CustomerDaoImpl" />
    <!-- 配置开启由注解驱动的事务处理 -->
    <tx:annotation-driven transaction-manager="transactionManager"/>
     <!-- 配置Spring需要扫描的包，
         Spring会扫描这些包以及子包中类的Spring注解 -->
     <context:component-scan base-package="mypack"/>
</beans>

/* Customer.java */
@Entity
@Table(name="CUSTOMERS")
public class Customer implements java.io.Serializable {
  @Id
  @GeneratedValue(generator="increment")
  @GenericGenerator(name="increment", strategy = "increment")
  @Column(name="ID")
  private Long id;
  @Column(name="NAME")
  private String name;
  @Column(name="AGE")
  private int age;
  //此处省略Customer类的构造方法、set方法和get方法
  …
}

/* CustomerDao.java */
public interface CustomerDao {
  public void insertCustomer(Customer customer);
  public void updateCustomer(Customer customer);
  public void deleteCustomer(Customer customer);
  public Customer findCustomerById(Long customerId);
  public List<Customer>findCustomerByName(String name);
}

/* CustomerDaoImpl.java */
package mypack;
import org.springframework.stereotype.Repository;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import java.util.List;
@Repository("CustomerDao")
public class CustomerDaoImpl implements CustomerDao {
    @PersistenceContext(name="entityManagerFactory")
    private EntityManager entityManager;
    public void insertCustomer(Customer customer) {
        entityManager.persist(customer);
    }
    public void updateCustomer(Customer customer) {
        entityManager.merge(customer);
    }
    public void deleteCustomer(Customer customer) {
        Customer c = findCustomerById(customer.getId());
        entityManager.remove(c);
    }
    public Customer findCustomerById(Long customerId) {
        return entityManager.find(Customer.class, customerId);
    }
    public List<Customer> findCustomerByName(String name) {
        return entityManager
                .createQuery("from Customer c where c.name = :name",
                                 Customer.class)
                .setParameter("name", name)
                .getResultList();
    }
}

<bean id="CustomerDao"class="mypack.CustomerDaoImpl"/>

/* CustomerService.java */
public interface CustomerService {
  public void insertCustomer(Customer customer);
  public void updateCustomer(Customer customer);
  public Customer findCustomerById(Long customerId);
  public void deleteCustomer(Customer customer);
  public List<Customer> findCustomerByName(String name);
}

/* CustomerServiceImpl.java */
package mypack;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import java.util.List;
@Service("CustomerService")
public class CustomerServiceImpl implements CustomerService{
  @Autowired
  private CustomerDao customerDao;
  @Transactional
  public void insertCustomer(Customer customer){
    customerDao.insertCustomer(customer);
  }
  @Transactional
  public void updateCustomer(Customer customer){
    customerDao.updateCustomer(customer);
  }
  @Transactional
  public Customer findCustomerById(Long customerId){
    return customerDao.findCustomerById(customerId);
  }
  @Transactional
  public void deleteCustomer(Customer customer){
    customerDao.deleteCustomer(customer);
  }
  @Transactional
  public List<Customer> findCustomerByName(String name){
    return customerDao.findCustomerByName(name);
  }
}

<bean id="CustomerService"class="mypack.CustomerServiceImpl"/>

/* Tester.java */
package mypack;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support
                      .ClassPathXmlApplicationContext;
import java.util.List;
public class Tester{
  private ApplicationContext ctx = null;
  private CustomerService customerService = null;
  public Tester(){
    ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
    customerService = ctx.getBean(CustomerService.class);
  }
  public void test(){
     Customer customer=new Customer("Tom",25);
     customerService.insertCustomer(customer);
     customer.setAge(36);
     customerService.updateCustomer(customer);
     Customer c=customerService.findCustomerById(customer.getId());
     System.out.println(c.getName()+": "+c.getAge()+"岁");
     List<Customer> customers=
               customerService.findCustomerByName(c.getName());
     for(Customer cc:customers)
         System.out.println(cc.getName()+": "+cc.getAge()+"岁");
     customerService.deleteCustomer(customer);
  } 
  public static void main(String args[]) throws Exception {
    new Tester().test();
  }
}