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

loading .properties in spring-context.xml and persistence.xml

提问by subes

is there a way to reference a .properties file in a spring-context.xml and a JPA persistence.xml?

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

I think I've seen somewhere an example of this in spring context files, though I can't remember where that was. Maybe someone knows this? About the persistence.xml I am actually unsure if this works at all.

我想我在 spring 上下文文件中的某个地方看到过这样的一个例子，尽管我不记得那是在哪里。也许有人知道这一点？关于persistence.xml，我实际上不确定这是否有效。

My aim is to change some properties between development and distribution configuration. The idea I have currently is to replace all properties manually in the files via ant from a template config. Though there should be a better way to do this. :)

我的目标是更改开发和分发配置之间的一些属性。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。:)

采纳答案by skaffman

You can reference external property files from a Spring bean definition file using a PropertyPlaceholderConfigurer. I don't think that will work for a JPA persistence.xml, although Spring's JPA support allows you to incorporate most, if not all, the content of persistence.xml into the beans file itself, in which case it would work fine.

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 支持允许您将大部分（如果不是全部）persistence.xml 的内容合并到 beans 文件本身中，在这种情况下它会正常工作。

回答by emeraldjava

Rather than using your build to create a prod or dev version of your persistence.xml, just move all property settings to your spring content.

而不是使用您的构建来创建您的 persistence.xml 的 prod 或 dev 版本，只需将所有属性设置移动到您的 spring 内容。

My persistence.xml is

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>

In my spring content, i then use the PropertyPlaceholderConfigurer to read dev/prod property values and set these into the entityManagerFactory bean

在我的 spring 内容中，我然后使用 PropertyPlaceholderConfigurer 读取 dev/prod 属性值并将它们设置到 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>