Question

我正在使用hibernate 4.2并使用tomee 1.7.4处理J2ee6。我需要编写多租户代码，可以根据需要连接到各种数据库。我尝试通过在persistence.xml中创建多个持久性单元来执行此操作，但在服务器启动期间，尝试验证与所有持久性单元的连接（所有这些单元在测试期间可能都不可用）。

我试图找到一些设置告诉你在启动时跳过连接的验证，但是找不到。因此，我开始使用函数

而不是从持久性单元创建实体管理器

javax.persistence.Persistence.createEntityManagerFactory(String persistenceUnitName, Map properties)

我的持久性xml没有任何属性。这有助于我解决这个问题，但是当我转移到这个模型时，我的缓存停止了工作，它之前正在工作。

任何人都可以建议某种方式我可以要求在启动时跳过验证持久性单元，或者我可以用我找到的其他方式启用缓存。

我以前的persistence.xml看起来像

<?xml version="1.0" encoding="UTF-8" ?><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_2_0.xsd"
version="2.0" xmlns="http://java.sun.com/xml/ns/persistence">
<persistence-unit name="localDB" transaction-type="RESOURCE_LOCAL">
    <provider>org.hibernate.ejb.HibernatePersistence</provider>
    <shared-cache-mode>ENABLE_SELECTIVE</shared-cache-mode>
    <properties>
        <property name="hibernate.connection.provider_class" value="org.hibernate.connection.C3P0ConnectionProvider" />
        <property name="hibernate.show_sql" value="false" />
        <property name="hibernate.format_sql" value="false" />

        <property name="hibernate.connection.driver_class"  value="com.mysql.jdbc.Driver" />
        <property name="hibernate.connection.url" value="jdbc:mysql://localhost:3306/xxxxxx?autoReconnect=true" />
        <property name="hibernate.connection.username" value="xxxxx" />
        <property name="hibernate.connection.password" value="xxxxx" />

        <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect"/>
        <property name="hibernate.c3p0.acquire_increment" value="1"/>
        <property name="hibernate.c3p0.max_size" value="40"/>
        <!-- it must be set to LESS than the wait_timout setting for the mysql server (this setting defaults to 28800 secs (8 hours)) -->
        <property name="hibernate.c3p0.idle_test_period" value="28680" />
        <property name="hibernate.c3p0.preferredTestQuery" value="select 1;" />
        <property name="hibernate.c3p0.timeout" value="60000"/>
        <property name="hibernate.connection.zeroDateTimeBehavior" value="convertToNull"/>
        <property name="hibernate.c3p0.debugUnreturnedConnectionStackTraces " value="true"/>
        <property name="debugUnreturnedConnectionStackTraces " value="true"/>
        <property name="hibernate.cache.use_second_level_cache" value="true" />
        <property name="hibernate.cache.use_query_cache" value="true" />
        <property name="hibernate.cache.region.factory_class" value="com.mc.hibernate.memcached.MemcachedRegionFactory" />
        <property name="hibernate.memcached.operationTimeout" value = "40000"/>
        <property name="hibernate.memcached.connectionFactory" value = "KetamaConnectionFactory"/>
        <property name="hibernate.memcached.hashAlgorithm" value = "HashAlgorithm.FNV1_64_HASH"/>
        <property name="hibernate.memcached.servers" value = "xxxxx:xxxx"/>

        <property name="hibernate.cache.region_prefix" value=""/>
    </properties>
</persistence-unit>

<persistence-unit name="production" transaction-type="RESOURCE_LOCAL">
    <provider>org.hibernate.ejb.HibernatePersistence</provider>
    <shared-cache-mode>ENABLE_SELECTIVE</shared-cache-mode>
    <properties>
        <property name="hibernate.connection.provider_class" value="org.hibernate.connection.C3P0ConnectionProvider" />
        <property name="hibernate.show_sql" value="false" />
        <property name="hibernate.format_sql" value="false" />

        <property name="hibernate.connection.driver_class"  value="com.mysql.jdbc.Driver" />
        <property name="hibernate.connection.url" value="jdbc:mysql://xxxxx:3306/thewalkindb?autoReconnect=true" />
        <property name="hibernate.connection.username" value="xxxx" />
        <property name="hibernate.connection.password" value="xxxxx" />

        <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect"/>
        <property name="hibernate.c3p0.acquire_increment" value="1"/>
        <property name="hibernate.c3p0.max_size" value="15"/>
        <!-- it must be set to LESS than the wait_timout setting for the mysql server (this setting defaults to 28800 secs (8 hours)) -->
        <property name="hibernate.c3p0.idle_test_period" value="28680" />
        <property name="hibernate.c3p0.preferredTestQuery" value="select 1;" />
        <property name="hibernate.c3p0.timeout" value="60000"/>
        <property name="hibernate.connection.zeroDateTimeBehavior" value="convertToNull"/>
        <property name="hibernate.c3p0.debugUnreturnedConnectionStackTraces " value="true"/>
        <property name="debugUnreturnedConnectionStackTraces " value="true"/>
        <property name="hibernate.cache.use_second_level_cache" value="true" />
        <property name="hibernate.cache.use_query_cache" value="true" />
        <property name="hibernate.cache.region.factory_class" value="com.mc.hibernate.memcached.MemcachedRegionFactory" />
        <property name="hibernate.memcached.operationTimeout" value = "40000"/>
        <property name="hibernate.memcached.connectionFactory" value = "KetamaConnectionFactory"/>
        <property name="hibernate.memcached.hashAlgorithm" value = "HashAlgorithm.FNV1_64_HASH"/>
        <property name="hibernate.memcached.servers" value = "xxxxxxxx"/>

        <property name="hibernate.cache.region_prefix" value=""/>
    </properties>
</persistence-unit>

这适用于缓存，但它不能让我灵活地跳过tomee启动验证

我的新持久性xml不尊重缓存，但允许我灵活性如下

<?xml version="1.0" encoding="UTF-8" ?>
<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_2_0.xsd"
version="2.0" xmlns="http://java.sun.com/xml/ns/persistence">
<persistence-unit name="localDB" transaction-type="RESOURCE_LOCAL">
    <provider>org.hibernate.ejb.HibernatePersistence</provider>
    <shared-cache-mode>ENABLE_SELECTIVE</shared-cache-mode>
    <properties></properties>
</persistence-unit>

<persistence-unit name="production" transaction-type="RESOURCE_LOCAL">
    <provider>org.hibernate.ejb.HibernatePersistence</provider>
    <shared-cache-mode>ENABLE_SELECTIVE</shared-cache-mode>
    <properties>
    </properties>
</persistence-unit>

我正在填充地图中的所有属性并调用该函数 javax.persistence.Persistence.createEntityManagerFactory（String persistenceUnitName，Map properties），但不知何故它不尊重缓存。

Answer 1

我没有获得验证和缓存之间的链接。如果您对实体管理器租户进行了外观，则意识到您只需要按实体管理器进行缓存，这意味着您不会检查生产持久性单元的本地缓存。

如果您需要单个实体管理器 - =您将在此模式下获得单个JPA缓存，这将合并本地和生产 - 您可以使用动态路由：http://tomee.apache.org/examples-trunk/dynamic-datasource-routing/README.html而不是动态持久性单元。 / p>

JPA不会在动态创建实体管理器工厂时遵循缓存

1 个答案: