Spring_Hibernate

Spring与Hiberante整合

通过hibernate的学习，我们知道，hibernate主要在hibernate.cfg.xml配置文件中

接下来我们看一下hibernate的一个配置文件

hibernate配置文件

hibernate.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
  "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
  "http://hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
  <session-factory>
    <!-- 指定连接数据库所用的驱动 -->
    <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
    <!-- 指定连接数据库的url，其中hibernate是本应用连接的数据库名 -->
    <property name="connection.url">jdbc:mysql://localhost/hibernate_test</property>
    <!-- 指定连接数据库的用户名 -->
    <property name="connection.username">root</property>
    <!-- 指定连接数据库的密码 -->
    <property name="connection.password">cheng</property>
    <!-- 指定连接池里最大连接数 -->
    <property name="hibernate.c3p0.max_size">20</property>
    <!-- 指定连接池里最小连接数 -->
    <property name="hibernate.c3p0.min_size">1</property>
    <!-- 指定连接池里连接的超时时长 -->
    <property name="hibernate.c3p0.timeout">5000</property>
    <!-- 指定连接池里最大缓存多少个Statement对象 -->
    <property name="hibernate.c3p0.max_statements">100</property>
    <property name="hibernate.c3p0.idle_test_period">3000</property>
    <property name="hibernate.c3p0.acquire_increment">2</property>
    <property name="hibernate.c3p0.validate">true</property>
    <!-- 指定数据库方言 -->
    <property name="dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>
    <!-- 根据需要自动创建数据表 -->
    <property name="hbm2ddl.auto">update</property><!--①-->
    <!-- 显示Hibernate持久化操作所生成的SQL -->
    <property name="show_sql">true</property>
    <!-- 将SQL脚本进行格式化后再输出 -->
    <property name="hibernate.format_sql">true</property>
    <!-- 避免这个错误信息Disabling contextual LOB creation as createClob() method threw error :java.lang.reflect.InvocationTargetException -->
    <property name="hibernate.temp.use_jdbc_metadata_defaults">false</property>
    <!-- 罗列所有持久化类的类名 -->
    <mapping class="com.wechat.entity.po.User"/>
    <mapping class="com.wechat.entity.po.Person"/>
  </session-factory>
</hibernate-configuration>

配置文件的作用

hibernate.cfg.xml文件的主要作用就是配置了一个session-factory

1. 在session-factory中主要通过property配置一些数据库的连接信息，我们知道，spring通常会将这种数据库连接用dataSource来表示，这样一来，hibernate.cfg.xml文件中的所有跟数据库连接的都可以干掉了，直接用spring的dataSource，而dataSource也可以用c3p0、dbcp等。
2. 在session-factory中通过property除了配置一些数据库的连接信息之外，还有一些hibernate的配置，比如方言、自动创建表机制、格式化sql等，这些信息也需要配置起来。
3. 还有最关键的一个持久化类所在路径的配置

当不采用spring整合的时候，我们使用hibernate时主要是用hibernate从sessionFactory中去的session，然后用session来操作持久化对象，而sessionFactory来自于配置文件。像下面这样：

StandardServiceRegistry registry = null;
SessionFactory sessionFactory = null;
Session session = null;
Transaction transaction = null;
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

@Before
public void init() {

  registry = new StandardServiceRegistryBuilder()
      .configure() // configures settings from hibernate.cfg.xml
      .build();
  sessionFactory = new MetadataSources( registry ).buildMetadata().buildSessionFactory();
  session = sessionFactory.openSession();
  //开始事务
  transaction = session.getTransaction();
  transaction.begin();
}

@Test
public void testSaveUser() {
  User user = new User();
  user.setUsername("张学友");
  user.setPassword("jacky");
  user.setRegistDate(sdf.format(new Date()));
  File file = new File("D:"+File.separator+"ubuntu.png");
  String fileName = file.getName();
  String prefix=fileName.substring(fileName.lastIndexOf(".")+1);
  System.out.println(prefix);
  InputStream input = null;
  try {
    input = new FileInputStream(file);

  } catch (FileNotFoundException e) {
    e.printStackTrace();
  }

  Blob image = null;
  try {
    image = Hibernate.getLobCreator(session).createBlob(input,input.available());
  } catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
  }
  user.setUserPic(image);
  session.save(user);
}

@After
public void destroy(){
  transaction.commit();
  session.close();
  sessionFactory.close();
  StandardServiceRegistryBuilder.destroy( registry 

Spring对hibernate的整合就是将上述三点通过spring配置起来，而hibernate最关键的sessionFactroy就是spring的一个bean

这些理解了整合就简单了，

SessionFactoryBean

spring的sessionFactroy像下面这样配置：

<!-- 加载配置文件 -->
  <context:property-placeholder location="classpath:jdbc.properties"
    file-encoding="utf-8" ignore-unresolvable="true" />

  <bean id="sessionFactory"
    class="org.springframework.orm.hibernate5.LocalSessionFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="packagesToScan">
      <list>
        <!-- 可以加多个包 -->
        <value>com.wechat.entity.po</value>
      </list>
    </property>
    <property name="hibernateProperties">
      <props>
        <prop key="hibernate.hbm2ddl.auto">${hibernate.hbm2ddl.auto}</prop>
        <prop key="hibernate.dialect">${hibernate.dialect}</prop>
        <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
        <prop key="hibernate.format_sql">${hibernate.format_sql}</prop>
        <prop key="hibernate.temp.use_jdbc_metadata_defaults">false</prop>
      </props>
    </property>
  </bean>

通过bean的配置可以看出该bean就是hibernate的sessionFactroy

因为它指向了org.springframework.orm.hibernate5.LocalSessionFactoryBean

在这个bean中主要配置了上面说的三点：

1. 数据源dataSource
2. hibernate的配置，包括方言，输出sql等
3. 持久化类的位置，通过包进行扫描

下面给出数据源dataSource的配置

dataSource

<!-- 配置数据源 -->
  <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
    destroy-method="close" p:driverClass="${jdbc.driverClassName}"
    p:jdbcUrl="${jdbc.url}" p:user="${jdbc.username}" p:password="${jdbc.password}"
    p:testConnectionOnCheckout="${jdbc.c3p0.testConnectionOnCheckout}"
    p:testConnectionOnCheckin="${jdbc.c3p0.testConnectionOnCheckin}"
    p:idleConnectionTestPeriod="${jdbc.c3p0.idleConnectionTestPeriod}"
    p:initialPoolSize="${jdbc.c3p0.initialPoolSize}" p:minPoolSize="${jdbc.c3p0.minPoolSize}"
    p:maxPoolSize="${jdbc.c3p0.maxPoolSize}" p:maxIdleTime="${jdbc.c3p0.maxIdleTime}" />

还有数据库的连接信息

jdbc.properties

#-----------------------------------------------------
# 数据库配置
#-----------------------------------------------------
#服务器地址
host=127.0.0.1
jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://${host}:3306/hibernate_test
jdbc.username=root
jdbc.password=cheng

#-----------------------------------------------------
# 适用于c3p0的配置
#-----------------------------------------------------
#-----------------------------------------------------
# c3p0反空闲设置，防止8小时失效问题28800
#-----------------------------------------------------
#idleConnectionTestPeriod要小于MySQL的wait_timeout
jdbc.c3p0.testConnectionOnCheckout=false
jdbc.c3p0.testConnectionOnCheckin=true
jdbc.c3p0.idleConnectionTestPeriod=3600
#-----------------------------------------------------
# c3p0连接池配置
#-----------------------------------------------------
#initialPoolSize, minPoolSize, maxPoolSize define the number of Connections that will be pooled.
#Please ensure that minPoolSize <= maxPoolSize.
#Unreasonable values of initialPoolSize will be ignored, and minPoolSize will be used instead.
jdbc.c3p0.initialPoolSize=10
jdbc.c3p0.minPoolSize=10
jdbc.c3p0.maxPoolSize=100
#maxIdleTime defines how many seconds a Connection should be permitted to go unused before being culled from the pool.
jdbc.c3p0.maxIdleTime=3600
#-----------------------------------------------------
# hibernate连接池配置
#-----------------------------------------------------
hibernate.connection.driverClass=com.mysql.jdbc.Driver
hibernate.connection.url=jdbc:mysql://${host}:3306/${dbName}
hibernate.dialect=org.hibernate.dialect.MySQL5Dialect
hibernate.show_sql=true
hibernate.format_sql=true
hibernate.hbm2ddl.auto=update

配置完这些还有spring强大的事务管理

<!-- 配置Hibernate事务管理器 -->
  <bean id="transactionManager"
    class="org.springframework.orm.hibernate5.HibernateTransactionManager">
    <property name="sessionFactory" ref="sessionFactory" />
  </bean>

  <!-- 配置事务异常封装 -->
  <bean id="persistenceExceptionTranslationPostProcessor"
    class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor" />

  <!-- 基于数据源的事务管理器 -->
  <!-- <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"
    p:dataSource-ref="dataSource" /> -->

  <!-- 配合<tx:advice>和<aop:advisor>完成了事务切面的定义 -->
  <!-- 使用强大的切点表达式是语言轻松定义目标方法 -->
  <aop:config proxy-target-class="true">
    <!-- 通过aop定义事务增强切面 -->
    <aop:pointcut expression=" execution(* com.wechat.service..*(..))"
      id="serviceMethod" />
    <!-- 引用事务增强 -->
    <aop:advisor advice-ref="txAdvice" pointcut-ref="serviceMethod" />
  </aop:config>
  <!-- 事务增强 -->
  <tx:advice id="txAdvice" transaction-manager="transactionManager">
    <!-- 事务属性定义 -->
    <tx:attributes>
      <tx:method name="*" />
    </tx:attributes>
  </tx:advice>

好了，这些配置好之后就可以使用在spring中配置的sessionFactroy了

UserDao

package com.wechat.dao;

import java.util.List;

import com.wechat.entity.po.User;

public interface UserDao {
  // 得到所有用户
  public List<User> getAllUser();

  // 检测用户名是否存在
  public boolean isExists(String username);

}

实现类

package com.wechat.dao.impl;

import java.util.ArrayList;
import java.util.List;

import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

import com.wechat.dao.UserDao;
import com.wechat.entity.po.User;
@Repository
public class UserDaoImpl implements UserDao {
  //注入sessionFactory
  @Autowired
  private SessionFactory sessionFactory;

  @SuppressWarnings("unchecked")
  @Override
  public List<User> getAllUser() {
    List<User> userList = new ArrayList<User>();
    String hsql="from User";
    Session session = sessionFactory.getCurrentSession();
    Query query = session.createQuery(hsql);
    userList = query.list();
    return userList;
  }

  @Override
  public boolean isExists(String username) {
    Query query = sessionFactory.openSession()
        .createQuery("from User u where u.username = :username").setParameter("username", username);
    System.out.println(query.list().size());
    return query.list().size()>0?true:false;
  }

}

UserService

package com.wechat.service.user;

import java.util.List;

import com.wechat.entity.po.User;

public interface UserService {
  public List<User> getAllUser();
  public boolean isExists(String username);

}

实现类

package com.wechat.service.user.impl;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Service;

import com.wechat.dao.UserDao;
import com.wechat.entity.po.User;
import com.wechat.service.user.UserService;
@Service
public class UserServiceImpl implements UserService {
  @Autowired
  private UserDao userDao;
  @Override
  public List<User> getAllUser() {
    return userDao.getAllUser();
  }
  @Override
  @Cacheable(cacheNames="isExists", key="#username")
  public boolean isExists(String username) {
    return userDao.isExists(username);
  }

}

因为事务管理是配置在service层，所以用service来测试

测试

package com.wechat.dao;

import java.util.List;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import com.wechat.entity.po.User;
import com.wechat.service.user.UserService;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = { "classpath:spring/spring-core.xml" })
public class UserServiceTest {
  @Autowired
  private UserService userService;

  @Test
  public void test() {
    List<User> userList = userService.getAllUser();
    for(User user:userList){
      System.out.println(user.getUsername());
    }

  }

}