hibernate(xml方式)

https://www.tutorialspoint.com/hibernate/hibernate_examples.htm

https://www.journaldev.com/3524/spring-hibernate-integration-example-tutorial

Spring 5.2.2.RELEASE + Hibernate 5.4.18.Final + MySQL 8.0.20

查询数据库

feat: Hibernate查询数据库

我这方式应该是直接耦合了Hibernate，因为是直接使用了sessionFactory，如果用JPA的话应该使用EntityManager。

https://www.javatpoint.com/jpa-vs-hibernate

引入包

其他包见 https://github.com/baicaihenxiao/SpringRoad/blob/ab7486fa4402c074df85e049900e79ff252244ef/pom.xml

  <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-orm</artifactId>
      <version>5.2.2.RELEASE</version>
  </dependency>

  <dependency>
      <groupId>org.hibernate</groupId>
      <artifactId>hibernate-entitymanager</artifactId>
      <version>5.4.18.Final</version>
  </dependency>

配置sessionFactory bean和transactionManager

sessionFactory bean里面指定hibernate.cfg.xml和*.hbm.xml位置。

<?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:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
   http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/aop https://www.springframework.org/schema/aop/spring-aop.xsd">

    <context:component-scan base-package="club.cser.springroad.hibernate"></context:component-scan>
    <context:property-placeholder location="classpath:db.properties"/>

<!--    <bean id="phone" class="club.cser.springroad.hibernate.entity.Phone"></bean>-->

    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="user" value="${jdbc.user}"></property>
        <property name="password" value="${jdbc.password}"></property>
        <property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property>
        <property name="driverClass" value="${jdbc.driverClass}"></property>
        <property name="initialPoolSize" value="${jdbc.initPoolSize}"></property>
        <property name="maxPoolSize" value="${jdbc.maxPoolSize}"></property>
    </bean>

    <bean id="sessionFactory" class="org.springframework.orm.hibernate5.LocalSessionFactoryBean">
        <property name="dataSource" ref="dataSource"></property>
        <property name="configLocation" value="classpath:hibernate.cfg.xml"></property>
        <property name="mappingLocations" value="classpath:*.hbm.xml"></property>
    </bean>

<!--    sessionFactory一定要绑定事务，否则调用sessionFactory.getCurrentSession()会报错，所以select的句子要设为readonly  -->
    <bean id="transactionManager" class="org.springframework.orm.hibernate5.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory"></property>
    </bean>

    <tx:advice id="txAdvice" transaction-manager="transactionManager">
        <tx:attributes>
<!--            默认get方法都是只读型事务 -->
            <tx:method name="get*" read-only="true"/>

<!--            未指定的方法传播方式是 REQUIRED -->
            <tx:method name="*"/>
        </tx:attributes>
    </tx:advice>

    <aop:config>
        <aop:pointcut id="txPointcut" expression="execution(* club.cser.springroad.hibernate.service.*.*(..))"/>
        <aop:advisor advice-ref="txAdvice" pointcut-ref="txPointcut" />
    </aop:config>


<!--    <bean class="club.cser.springroad.beans.handler.MyBeanPostProcessor"></bean>-->

</beans>

hibernate.cfg.xml和*.hbm.xml

hibernate.cfg.xml配置sessionFactory的一些属性

*.hbm.xml将java类和数据表进行映射

使用

@Repository
public class PhoneDao {
    @Resource
    private SessionFactory sessionFactory;

    private Session getSession() {
        return sessionFactory.getCurrentSession();
    }

    public String getManufactureById(Integer id) {
        // Phone标红是idea没有识别，在sessionFactory配置了mappingLocations。如果在hibernate.cfg.xml里配置mapping的话就不标红了。
        String hql = "SELECT p.manufacture from Phone p where p.id = ?1";
        Query query = getSession().createQuery(hql).setParameter(1, id);
        return (String)query.uniqueResult();
    }

    // hql 里的Phone和saleDate不是数据库里表和列的名字，而是程序里定义的类和字段的名字。0
    public Date getSaleDateById(Integer id) {
        String hql = "SELECT p.saleDate from Phone p where p.id = ?1";
        Query query = getSession().createQuery(hql).setParameter(1, id);
        return (Date)query.uniqueResult();
    }
}

Hibernate事务

sessionFactory.getCurrentSession()一定会开启事务

https://stackoverflow.com/questions/29690240/hibernate-sessionfactory-getcurrentsession-without-transactional

sessionFactory一定要绑定事务，否则调用sessionFactory.getCurrentSession()会报错，所以select的句子要设为readonly提高效率。

feat: update insert 和 事务

Exception in thread "main" org.hibernate.HibernateException: Could not obtain transaction-synchronized Session for current thread
	at org.springframework.orm.hibernate5.SpringSessionContext.currentSession(SpringSessionContext.java:143)
	at org.hibernate.internal.SessionFactoryImpl.getCurrentSession(SessionFactoryImpl.java:475)
	at club.cser.springroad.hibernate.dao.PhoneDao.getSession(PhoneDao.java:19)
	at club.cser.springroad.hibernate.dao.PhoneDao.addPhone(PhoneDao.java:48)
	at club.cser.springroad.hibernate.service.PhoneService.testTransaction(PhoneService.java:36)
	at club.cser.springroad.hibernate.client.HibernateXMLClient.main(HibernateXMLClient.java:26)

遇到的问题

hbm.xml not found

报错org.hibernate.MappingNotFoundException: resource: *hbm.xml not found

https://stackoverflow.com/questions/7127608/org-hibernate-mappingnotfoundexception-resource-hbm-xml-not-found

hbm.xml也要放在src/main/resources里，不能放在src/main/java，即使路径写对了，cmd+左键能导航进去也不行。

不能自动创建表

<property name="hibernate.hbm2ddl.auto">create</property>这个不管是create还是update都不能自动创建表，不知道为啥

✅ 已解决

https://stackoverflow.com/questions/1459265/hibernate-create-mysql-innodb-tables-instead-of-myisam

这个里面说用<property name="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>，idea提示这个已经废弃了，用下面这个，update就可以自动生成数据库了。

用这个
<property name="hibernate.dialect.storage_engine">innodb</property>

而不是视频里说的
<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>

hibernate版本

用5.2.17.Final版本，会提示一个properties找不到和下面这个，但是没有报错，网上有说不要用5.2版本，我换成了5.4的版本。换成5.2.17.Final又不提示properties找不到了。。。

2020-07-26 12:21:15.269 [INFO] main [org.hibernate.engine.transaction.jta.platform.internal.JtaPlatformInitiator.initiateService:52] 
HHH000490: Using JtaPlatform implementation: [org.hibernate.engine.transaction.jta.platform.internal.NoJtaPlatform]