在spring-context.xml和persistence.xml中加载.properties

Question

有没有办法在spring-context.xml和JPA persistence.xml中引用.properties文件？

我想我在春天的上下文文件中看到了一个这样的例子,虽然我不记得那是什么.也许有人知道这个？关于persistence.xml我实际上不确定这是否有效.

我的目标是在开发和分发配置之间更改某些属性.我目前的想法是通过模板配置中的ant手动替换文件中的所有属性.虽然应该有更好的方法来做到这一点.:)

Answer 1

不要使用构建来创建persistence.xml的prod或dev版本,只需将所有属性设置移动到spring内容即可.

我的persistence.xml是

<?xml version="1.0" encoding="UTF-8"?>
<persistence
    xmlns="http://java.sun.com/xml/ns/persistence"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"
    version="1.0">
    <persistence-unit name="JPAService" transaction-type="RESOURCE_LOCAL">   
    </persistence-unit>
</persistence>

在我的spring内容中,然后使用PropertyPlaceholderConfigurer读取dev/prod属性值并将它们设置为entityManagerFactory bean

<?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:aop="http://www.springframework.org/schema/aop"
    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-2.5.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd">

    <bean class="org.springframework.context.annotation.CommonAnnotationBeanPostProcessor"/>
    <bean class="org.springframework.beans.factory.annotation.RequiredAnnotationBeanPostProcessor"/>    
    <bean class="org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor"/>
    <bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor"/>

    <bean id="propertyPlaceholder" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="systemPropertiesModeName" value="SYSTEM_PROPERTIES_MODE_OVERRIDE"/>
        <property name="ignoreResourceNotFound" value="true"/>
        <property name="locations">
            <list>
                <value>classpath:dev.properties</value>
            </list>
        </property>
    </bean>

    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="${datasource.driverClassName}"/>
        <property name="url" value="${datasource.url}"/>
        <property name="username" value="${datasource.username}"/>
        <property name="password" value="${datasource.password}"/>
    </bean>

    <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"> 
        <property name="persistenceXmlLocation" value="classpath:./META-INF/persistence.xml"/>
        <property name="persistenceUnitName" value="JPAService"/>
        <property name="dataSource" ref="dataSource"/>

        <property name="jpaVendorAdapter"> 
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"> 
                <property name="databasePlatform" value="org.hibernate.dialect.OracleDialect"/> 
                <property name="showSql" value="true" /> 
                <property name="generateDdl" value="true"/>
            </bean> 
        </property>
        <property name="jpaProperties">
                <!-- set extra properties here, e.g. for Hibernate: -->
            <props>
            <prop key="hibernate.hbm2ddl.auto">${hibernate.hbm2ddl.auto}</prop>
            </props>
        </property>
    </bean>

    <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactory"/>
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <tx:annotation-driven transaction-manager="transactionManager" proxy-target-class="false"/>
</beans>

Answer 2

您可以使用PropertyPlaceholderConfigurer从Spring bean定义文件中引用外部属性文件.我认为这不适用于JPA persistence.xml,尽管Spring的JPA支持允许您将大多数(如果不是全部)persistence.xml的内容合并到beans文件本身中,在这种情况下它可以正常工作.