我使用Spring配置的Hibernate(通过JPA),当我启动我的应用程序(在Tomcat 6上部署的war)时,我收到此错误:
org.hibernate.HibernateException: Connection cannot be null when 'hibernate.dialect' not set
这似乎很奇怪,因为我将冬眠方言设置如下:
p:databasePlatform="org.hibernate.dialect.MySQL5Dialect
有关更多信息,请在此处使用我的完整应用程序上下文.xml:
<?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:p="http://www.springframework.org/schema/p"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd">
<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource"
p:driverClassName="com.mysql.jdbc.Driver"
p:url="jdbc:mysql://localhost/room_management" p:username="root" p:password=""/>
<bean id="entityManagerFactory"
class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"
p:dataSource-ref="dataSource" p:persistenceUnitName="RoomManagement">
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"
p:database="MYSQL"
p:databasePlatform="org.hibernate.dialect.MySQL5Dialect"
p:showSql="true"/>
</property>
</bean>
<bean id="transactionManager"
class="org.springframework.orm.jpa.JpaTransactionManager"
p:entityManagerFactory-ref="entityManagerFactory"/>
<context:annotation-config/>
<context:component-scan base-package="com.parisdescartes.roommanagement.*"/>
<tx:annotation-driven/>
</beans>
因此,我决定在META-INF/persistence.xml文件中精确地使用Hibernate方言,这一次有效。这是我如何精确定位的:
<properties>
<property name="hibernate.dialect"
value="org.hibernate.dialect.MySQL5Dialect"/>
</properties>
你知道为什么不使用 Spring 配置设置休眠方言吗?
不确定为什么它不适用于您的配置。也许使用 p: 注释出了点问题。我将发布我的代码(适用于我的配置)以尝试它是否可以修复您的代码!:)
<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">
<property name="showSql" value="false"/>
<property name="generateDdl" value="true"/>
<property name="databasePlatform" value="org.hibernate.dialect.MySQL5Dialect"/>
</bean>
</property>
</bean>
祝你好运!
有点晚了,但我认为这可以增加价值。如果您指定database
属性,则不一定需要添加databasePlatform
属性,适配器本身将找出方言。
<property name="database" value="MYSQL" />
来自org.springframework.orm.jpa.vendor.HibernateJPAVendorAdapter
的相关代码
protected Class determineDatabaseDialectClass(Database database) {
switch (database) {
case DB2: return DB2Dialect.class;
case DERBY: return DerbyDialect.class;
case H2: return H2Dialect.class;
case HSQL: return HSQLDialect.class;
case INFORMIX: return InformixDialect.class;
case MYSQL: return MySQLDialect.class;
case ORACLE: return Oracle9iDialect.class;
case POSTGRESQL: return PostgreSQLDialect.class;
case SQL_SERVER: return SQLServerDialect.class;
case SYBASE: return SybaseDialect.class;
default: return null;
}
}
驱动程序DataSource
自动检测方言。所以下界hibernate.dialect
不需要database
。如果发生异常'hibernate.dialect' not set
,这通常意味着,而不是数据库连接出现问题:
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"
p:dataSource-ref="dataSource"
p:packagesToScan="ru.javawebinar.**.model">
<property name="jpaPropertyMap">
<map>
<entry key="#{T(org.hibernate.cfg.AvailableSettings).FORMAT_SQL}" value="${hibernate.format_sql}"/>
<entry key="#{T(org.hibernate.cfg.AvailableSettings).USE_SQL_COMMENTS}" value="${hibernate.use_sql_comments}"/>
</map>
</property>
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"
p:showSql="${jpa.showSql}">
</bean>
</property>
</bean>