Question

我想在Spring JSON API应用程序中实现环境配置文件，以处理多个环境，开发，测试和生产。我见过Unable to use JNDI DataSource provided by Tomcat in Spring?等例子。我此时只需要处理不同的数据库设置，但稍后我可能需要额外的bean配置，具体取决于环境。

我的persistence.xml目前看起来像这样。

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" 
    xmlns="http://xmlns.jcp.org/xml/ns/persistence" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">

    <persistence-unit name="BPPersistenceUnit" transaction-type="RESOURCE_LOCAL">

        <!-- JNDI datasource -->
        <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
        <non-jta-data-source>java:comp/env/jdbc/BloodPressureDB</non-jta-data-source>

        <!-- Hibernate Settings -->
        <properties>

            <!-- java persistence settings -->
            <property name="javax.persistence.jdbc.driver" value="org.postgresql.Driver" />
            <property name="javax.persistence.jdbc.url" value="jdbc:postgresql://127.0.0.1:5432/jkratz" />
            <property name="javax.persistence.jdbc.user" value="tomcat" />
            <property name="javax.persistence.jdbc.password" value="t0mc@t2014" />

            <!-- hibernate settings -->
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.format_sql" value="true" />
            <property name="hibernate.connection.charSet" value="UTF-8" />
            <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQL9Dialect" />
            <property name="hibernate.hbm2ddl.auto" value="validate" />

        </properties>

    </persistence-unit>
</persistence>

我已经看过不同的例子，所以我对如何实施有点困惑。

您仍然可以使用Tomcat数据源配置吗？如果是这样，它如何知道使用哪个配置文件？
如何为多个环境配置persistence.xml？ jdbc连接道具甚至应该在persistence.xml中
如何在不重新编译的情况下设置活动配置文件？

Answer 1

1。你还能使用Tomcat数据源配置吗？如果是这样，它如何知道使用哪个配置文件？

您可以使用Tomcat数据库配置，但数据源定义与Spring或Spring配置文件无关。如果您正在使用JNDI方法，那么您可能已定义了多个数据源，并且可以通过配置文件属性指定您在应用程序中使用的数据源，但实际定义与Spring无关。

或者，您可以使用非JNDI数据源，即在Spring中配置，也许使用配置文件。

2。如何为多个环境配置persistence.xml？ jdbc连接道具甚至应该在persistence.xml中

不，您在使用Spring时可能只需要一个最小的persistence.xml，或者根本不需要。

3。如何在不重新编译的情况下设置活动配置文件？

你不能

以下是启动和运行非JNDI数据源所需的全部内容。

Spring配置示例（非JNDI）：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:jpa="http://www.springframework.org/schema/data/jpa" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa.xsd http://www.springframework.org/schema/context 
          http://www.springframework.org/schema/context/spring-context-3.2.xsd">

    <jpa:repositories base-package="uk.co.certait.spring.data.repository" />

    <bean id="entityManagerFactory"
        class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="jpaVendorAdapter" ref="jpaAdapter"></property>
        <property name="persistenceUnitName" value="persistenceUnit" />
        <property name="dataSource" ref="dataSource" />
        <property name="jpaProperties">
            <props>
                <prop key="hibernate.hbm2ddl.auto">${hibernate.ddl.auto}</prop>
                <prop key="hibernate.dialect">${hibernate.dialect}</prop>
                <prop key="hibernate.show_sql">${hibernate.show.sql}</prop>
                <prop key="hibernate.format_sql">true</prop>
                <prop key="hibernate.cache.use_second_level_cache">${hibernate.enable.cache}</prop>
                <prop key="hibernate.cache.provider_class">org.hibernate.cache.EhCacheProvider</prop>
            </props>
        </property>
    </bean>

    <bean id="jpaAdapter"
        class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter" />

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

Spring数据源定义示例

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="
            http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd">

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

</beans>

Spring配置文件定义示例：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd">

    <beans profile="default">
        <bean id="applicationPropertiesPlaceholder"
            class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
            <property name="locations">
                <list>
                    <value>classpath:profiles/hsqldb.profile.properties</value>
                </list>
            </property>
        </bean>
    </beans>

    <beans profile="hsqldb">
        <bean id="applicationPropertiesPlaceholder"
            class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
            <property name="locations">
                <list>
                    <value>classpath:profiles/hsqldb.profile.properties</value>
                </list>
            </property>
        </bean>
    </beans>

    <beans profile="mysql">
        <bean id="applicationPropertiesPlaceholder"
            class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
            <property name="locations">
                <list>
                    <value>classpath:profiles/mysql.profile.properties</value>
                </list>
            </property>
        </bean>
    </beans>

    <beans profile="mssql">
        <bean id="applicationPropertiesPlaceholder"
            class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
            <property name="locations">
                <list>
                    <value>classpath:profiles/mssql.profile.properties</value>
                </list>
            </property>
        </bean>
    </beans>

</beans>

Minimal Persisteance.XML

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="2.0"
    xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
    <persistence-unit name="persistenceUnit"
        transaction-type="RESOURCE_LOCAL">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <properties>
            <property name="hibernate.ejb.naming_strategy" value="org.hibernate.cfg.ImprovedNamingStrategy" />
            <property name="hibernate.connection.charSet" value="UTF-8" />
        </properties>
    </persistence-unit>
</persistence>

示例配置文件属性文件：

#MySQL
#database.url=jdbc:mysql://localhost:3306/test
database.url=jdbc:log4jdbc:mysql://localhost:3306/test
#database.driver=com.mysql.jdbc.Driver
database.driver=net.sf.log4jdbc.DriverSpy
database.username=root
database.password=password
hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect

hibernate.show.sql=false
hibernate.ddl.auto=create
hibernate.enable.cache=false

Answer 2

由于我与Tomcat没有多少共同之处，我只会提供一个类似问题的链接：
Using dynamic Datasource with Tomcat

JPA允许在单个persistence.xml文件中定义多个持久性单元您至少需要将其名称更改为其包装范围内的唯一名称（就Web Archive，EJB JAR等而言）：

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" 
    xmlns="http://xmlns.jcp.org/xml/ns/persistence" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence 
    http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">

    <persistence-unit name="BPPersistenceUnit-postgres" 
                      transaction-type="RESOURCE_LOCAL">
        <!-- JNDI datasource -->
        ...
        <!-- properties -->
        ...
    </persistence-unit>
    <persistence-unit name="BPPersistenceUnit-mysql" 
                      transaction-type="RESOURCE_LOCAL">
        <!-- JNDI datasource -->
        ...
        <!-- properties -->
        ...
    </persistence-unit>
</persistence>

JPA允许使用重载的createEntityManagerFactory方法在运行时指定持久性提供程序属性：

// dynamic configuration for PostgreSQL
Map<String, String> props = new HashMap<>();
props.put("javax.persistence.jdbc.driver", "org.postgresql.Driver");
...
EntityManagerFactory pgEmf = 
Persistence.createEntityManagerFactory("BPPersistenceUnit-postgres", props);

// dynamic configuration for MySQL
...

传递给该方法的属性与persistence.xml中已指定的属性相结合，这样您就可以获得真正可配置的多用途和动态配置。

弹簧环境简介＆amp; JPA

2 个答案: