spring-Hibernate 5命名策略配置

Z时代
2024-01-10
分类：问答

我正在使用postgresql数据库和spring + hibernate框架编写应用程序。

我将spring框架从4.1.5.RELEASE升级到4.2.0.RELEASE版本，并将hibernate框架从4.3.7.Final升级到了5.0.0.Final版本。

升级后，我在NamingStrategy中遇到问题。在postgresql数据库中，表列名称以小写字母用下划线分隔，在应用程序层中，bean属性以驼峰字母表示。

这是旧版本的有效Spring配置文件：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns="http://www.springframework.org/schema/beans"
       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.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/tx
        http://www.springframework.org/schema/tx/spring-tx.xsd">
    <context:component-scan base-package="fms" />
    <bean id="microFmsDataSource" class="org.apache.tomcat.jdbc.pool.DataSource" destroy-method="close">
        <property name="driverClassName" value="org.postgresql.Driver" />
        <property name="url" value="***" />
        <property name="username" value="***" />
        <property name="password" value="***" />
        <property name="testOnBorrow" value="true" />
        <property name="testOnReturn" value="true" />
        <property name="testWhileIdle" value="true" />
        <property name="validationQuery" value="select 1" />
        <property name="initialSize" value="5" />
        <property name="minIdle" value="10" />
        <property name="maxIdle" value="100" />
        <property name="maxActive" value="100" />
        <property name="removeAbandoned" value="true" />
    </bean>
    <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="dataSource" ref="microFmsDataSource"/>
        <property name="packagesToScan">
            <list>
                <value>fms</value>
            </list>
        </property>
        <property name="jpaVendorAdapter">
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter" />
        </property>
        <property name="jpaPropertyMap">
            <map>
                <entry key="hibernate.cache.provider_class" value="org.hibernate.cache.NoCacheProvider" />
                <entry key="hibernate.hbm2ddl.auto" value="validate" />
                <entry key="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect" />
                <entry key="hibernate.show_sql" value="true" />
                <entry key="hibernate.format_sql" value="true" />
                <entry key="hibernate.ejb.naming_strategy" value="org.hibernate.cfg.ImprovedNamingStrategy" />
            </map>
        </property>
    </bean>
    <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactory" />
    </bean>
    <tx:annotation-driven transaction-manager="transactionManager"/>
</beans>

升级后，我更改了NamingStrategy配置：

<entry key="hibernate.ejb.naming_strategy" value="org.hibernate.cfg.ImprovedNamingStrategy" />

像这样：

<entry key="hibernate.implicit_naming_strategy" value="***" />

并尝试了hibernate javadoc中列出的所有选项的变体：https : //docs.jboss.org/hibernate/orm/5.0/javadocs/org/hibernate/cfg/AvailableSettings.html#IMPLICIT_NAMING_STRATEGY

但没有成功。

您能告诉我Hibernate 5中改进的NamingStrategy的替代方案是什么，并提供一个有效的配置示例吗？

回答：

我想我找到了解决方案。

为了实现我的目标，我使用hibernate.physical_naming_strategy配置而不是hibernate.implicit_naming_strategy。

我创建了PhysicalNamingStrategy接口的实现，该接口模拟了原始ImprovedNamingStrategy类的部分功能：

package fms.util.hibernate;
import org.apache.commons.lang.StringUtils;
import org.hibernate.boot.model.naming.Identifier;
import org.hibernate.boot.model.naming.PhysicalNamingStrategy;
import org.hibernate.engine.jdbc.env.spi.JdbcEnvironment;
public class ImprovedNamingStrategy implements PhysicalNamingStrategy {
    @Override
    public Identifier toPhysicalCatalogName(Identifier identifier, JdbcEnvironment jdbcEnv) {
        return convert(identifier);
    }
    @Override
    public Identifier toPhysicalColumnName(Identifier identifier, JdbcEnvironment jdbcEnv) {
        return convert(identifier);
    }
    @Override
    public Identifier toPhysicalSchemaName(Identifier identifier, JdbcEnvironment jdbcEnv) {
        return convert(identifier);
    }
    @Override
    public Identifier toPhysicalSequenceName(Identifier identifier, JdbcEnvironment jdbcEnv) {
        return convert(identifier);
    }
    @Override
    public Identifier toPhysicalTableName(Identifier identifier, JdbcEnvironment jdbcEnv) {
        return convert(identifier);
    }
    private Identifier convert(Identifier identifier) {
        if (identifier == null || StringUtils.isBlank(identifier.getText())) {
            return identifier;
        }
        String regex = "([a-z])([A-Z])";
        String replacement = "$1_$2";
        String newName = identifier.getText().replaceAll(regex, replacement).toLowerCase();
        return Identifier.toIdentifier(newName);
    }
}

创建此类后，我从以下位置更改了配置：

<entry key="hibernate.ejb.naming_strategy" value="org.hibernate.cfg.ImprovedNamingStrategy" />

对此：

<entry key="hibernate.physical_naming_strategy" value="fms.util.hibernate.ImprovedNamingStrategy" />

现在一切正常。

此解决方案仅覆盖的一小部分ImprovedNamingStrategy。在我的项目中，对于表映射和联接映射，我总是显式指定表或联接列的名称。我仅对列名依赖隐式名称转换。所以这个简单的解决方案对我来说是可以接受的。

这是我的Spring配置文件的完整示例：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns="http://www.springframework.org/schema/beans"
       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.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/tx
        http://www.springframework.org/schema/tx/spring-tx.xsd">
    <context:component-scan base-package="fms" />
    <bean id="microFmsDataSource" class="org.apache.tomcat.jdbc.pool.DataSource" destroy-method="close">
        <property name="driverClassName" value="org.postgresql.Driver" />
        <property name="url" value="***" />
        <property name="username" value="***" />
        <property name="password" value="***" />
        <property name="testOnBorrow" value="true" />
        <property name="testOnReturn" value="true" />
        <property name="testWhileIdle" value="true" />
        <property name="validationQuery" value="select 1" />
        <property name="initialSize" value="5" />
        <property name="minIdle" value="10" />
        <property name="maxIdle" value="100" />
        <property name="maxActive" value="100" />
        <property name="removeAbandoned" value="true" />
    </bean>
    <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="dataSource" ref="microFmsDataSource"/>
        <property name="packagesToScan">
            <list>
                <value>fms</value>
            </list>
        </property>
        <property name="jpaVendorAdapter">
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter" />
        </property>
        <property name="jpaPropertyMap">
            <map>
                <entry key="hibernate.cache.provider_class" value="org.hibernate.cache.NoCacheProvider" />
                <entry key="hibernate.hbm2ddl.auto" value="validate" />
                <entry key="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect" />
                <entry key="hibernate.show_sql" value="true" />
                <entry key="hibernate.format_sql" value="true" />
                <entry key="hibernate.physical_naming_strategy" value="fms.util.hibernate.ImprovedNamingStrategy" />
            </map>
        </property>
    </bean>
    <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactory" />
    </bean>
    <tx:annotation-driven transaction-manager="transactionManager"/>
</beans>