春季jpa冬眠与更多的数据源 [英] spring jpa hibernate with more datasources

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本文介绍了春季jpa冬眠与更多的数据源的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我必须在Hibernate，Jpa的应用程序（spring）中使用两个不同的数据库。
我想将不同的表格直接定义到不同的数据源。
所以我使用了两个不同的持久化单元，我尝试使用 

 < property name =packagesToScanvalue = it.two.app.domain.first/>

和

 < property name =packagesToScanvalue =it.two.app.domain.second/>

将不同的表放入不同的包中。
但它不起作用。
事实上，所有的表都与第一个数据源相关。
，然后我试图写入持久化XML文件中类
的名称，例如

 < / p> persistence-unit name =persistenceFirsttransaction-type =RESOURCE_LOCAL> 
< class> it.two.app.domain.first.OneTable< / class> 
< exclude-unlisted-classes /> 
< / persistence-unit>



和

it.two.app.domain.second.OtherTable



但是，当我运行日志说
表'firstDB.other-table'不存在
和我使用到服务文件中

$ pre $ c $ @PersistenceContext（unitName =persistenceFirst）
private EntityManager em;

和

  @PersistenceContext（unitName =persistenceSecond）
 EntityManager em;

你有一些想法吗？
Thi是数据源XML文件 

 <？xml version =1.0encoding =UTF-8 >？; 
< beans xmlns =http://www.springframework.org/schema/beans
 xmlns：xsi =http://www.w3.org/2001/XMLSchema-instance
 xmlns：context =http://www.springframework.org/schema/context
 xmlns：jdbc =http://www.springframework.org/schema/jdbc
 xmlns ：jpa =http://www.springframework.org/schema/data/jpa
 xmlns：tx =http://www.springframework.org/schema/tx
 xmlns：p =http://www.springframework.org/schema/p
 xsi：schemaLocation =http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/ jdbc / spring-jdbc-3.1.xsd 
 http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd 
 http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.0.xsd 
 http：//www.springframework .org / schema / tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd 
 http://www.springframework.org/schema/context http：// www。 springframework.org/模式/上下文/弹簧上下文3.1.xsd> 
 
<！ - 第一个数据源 - > 
< context：property-placeholder location =classpath：jdbc-first.properties/> 
 p：driverClassName =$ {jdbc.driverClassName}p：url =$ {jdbc.databaseurl }
p：username =$ {jdbc.username}p：password =$ {jdbc.password}/> 
 <！ - 秒数据源 - > 
< context：property-placeholder location =classpath：jdbc-second.properties/> 
< bean id =dataSourceSecondclass =org.apache.commons.dbcp.BasicDataSource
p：driverClassName =$ {jdbc.driverClassName}p：url =$ {jdbc.databaseurl }
p：username =$ {jdbc.username}p：password =$ {jdbc.password}/> 
 
 
< bean id =transactionManagerFirstclass =org.springframework.orm.jpa.JpaTransactionManager
 p：entityManagerFactory-ref =emfFirst/> 
 
< bean id =transactionManagerSecondclass =org.springframework.orm.jpa.JpaTransactionManager
 p：entityManagerFactory-ref =emfSecond/> 
 
< tx：annotation-driven transaction-manager =transactionManagerFirst/> 
< tx：annotation-driven transaction-manager =transactionManagerSecond/> 
 
 
  entity-manager-factory-ref =emfFirsttransaction-manager -ref =transactionManagerFirst/> 
 
< jpa：repositories base-package =it.two.app.repository.second
 entity-manager-factory-ref =emfSecondtransaction-manager-ref = transactionManagerSecond/> 
 
< bean id =emfFirst
 class =org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean> 
< property name =persistenceUnitNamevalue =persistenceFirst/> 
< property name =persistenceXmlLocationvalue =classpath：/META-INF/persistence-first.xml/> 
< property name =jpaVendorAdapter> 
< bean class =org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter/> 
< / property> 
 
< property name =dataSourceref =dataSourceFirst/> 
< property name =packagesToScanvalue =it.two.app.domain.first/> 
< property name =jpaProperties> 
<道具> 
< prop key =hibernate.dialect> org.hibernate.dialect.MySQLDialect< / prop> 
< prop key =hibernate.max_fetch_depth> 3< / prop> 
< prop key =hibernate.jdbc.fetch_size> 50< / prop> 
< prop key =hibernate.jdbc.batch_size> 10< / prop> 
< /道具> 
< / property> 
 
< / bean> 
 
< bean id =emfSecondclass =org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean> 
< property name =persistenceUnitNamevalue =persistenceSecond/> 
< property name =persistenceXmlLocationvalue =classpath：/ META-INF / persistence- second.xml/> 
< property name =jpaVendorAdapter> 
< bean class =org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter/> 
< / property> 
< property name =dataSourceref =dataSourceSecond/> 
< property name =packagesToScanvalue =it.two.app.domain.second/> 
< property name =jpaProperties> 
<道具> 
< prop key =hibernate.dialect> org.hibernate.dialect.MySQLDialect< / prop> 
< prop key =hibernate.max_fetch_depth> 3< / prop> 
< prop key =hibernate.jdbc.fetch_size> 50< / prop> 
< prop key =hibernate.jdbc.batch_size> 10< / prop> 
< /道具> 
< / property> 
 
< / bean> 
 
< / beans>

解决方案!!!!!!
我解决了这个问题。
简单

 <！ -  first datasource  - > 
 p：driverClassName =com.mysql.jdbc.Driverp：url =url ... 。
p：username =usernamep：password =password/> 
 <！ - 秒数据源 - > 
< bean id =dataSourceSecondclass =org.apache.commons.dbcp.BasicDataSource
p：driverClassName =com.mysql.jdbc.Driverp：url =url2 ... 。
p：username =username2p：password =password2/>


解决方案

如果您想使用多个 DataSource 位于 Spring + JPA 。


  1. 在 persistence.xml 中创建两个或多个 PersistenceUnit 。
  2. 创建<$对于 spring-beans.xml 中的每个 PersistenceUnit ，c $ c> EntityManagerFactory li>

更多参考资料。


  1. 多个数据库使用Spring + Hibernate + JPA

  2. 使用Spring 3，Hibernate 3访问多个数据库 12 / handling-transaction-with-multiple.htmlrel =nofollow noreferrer>使用Spring 3.0和Hibernate 3.0的多个数据库


$ b $在您的DAO类中。

  @PersistenceContext（unitName =JPA_1）
 private EntityManager em_1; 
 
 @PersistenceContext（unitName =JPA_2）
私人EntityManager em_2;

Conig persistence.xml 

 < persistence-unit name =JPA_1type =RESOURCE_LOCAL> 
 .... 
< / persistence-unit> 
 
 
< persistence-unit name =JPA_2type =RESOURCE_LOCAL> 
 .... 
< / persistence-unit>

配置：spring-beans.xml 

 < bean id =entityManagerFactory1class =org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean> 
< property name =persistenceUnitNamevalue =JPA_1/> 
< property name =jpaVendorAdapterref =jpaVendorAdapter/> 
< property name =jpaDialect> 
< bean class =org.springframework.orm.jpa.vendor.EclipseLinkJpaDialect/> <  - 如果有必要，请用休眠替换。 
< / property> 
< property name =jpaPropertyMap> 
<道具> 
< prop key =eclipselink.weaving> false< / prop> <  - 如果有必要，请用休眠替换。 
< /道具> 
< / property> 
< property name =loadTimeWeaver> 
< bean class =org.springframework.instrument.classloading.InstrumentationLoadTimeWeaver> 
< / bean> 
< / property> 
< / bean> 
 
< bean id =entityManagerFactory2class =org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean> 
< property name =persistenceUnitNamevalue =JPA_2/> 
< property name =jpaVendorAdapterref =jpaVendorAdapter/> 
< property name =jpaDialect> 
< bean class =org.springframework.orm.jpa.vendor.EclipseLinkJpaDialect/> <  - 如果有必要，请用休眠替换。 
< / property> 
< property name =jpaPropertyMap> 
<道具> 
< prop key =eclipselink.weaving> false< / prop> <  - 如果有必要，请用休眠替换。 
< /道具> 
< / property> 
< property name =loadTimeWeaver> 
< bean class =org.springframework.instrument.classloading.InstrumentationLoadTimeWeaver> 
< / bean> 
< / property> 
< / bean> 
 
< bean id =jpaVendorAdapterclass =org.springframework.orm.jpa.vendor.EclipseLinkJpaVendorAdapter> <  - 如果有必要，请用休眠替换。 
< property name =databasePlatformvalue =org.eclipse.persistence.platform.database.MySQLPlatform/> 
<！ - < property name =databasePlatformvalue =org.eclipse.persistence.platform.database.OraclePlatform/>  - > 
< property name =generateDdlvalue =false/> 
< property name =showSqlvalue =true/> 
< / bean>


I have to use two different database in my application(spring) with Hibernate,Jpa. I'd like to define the different table directly to the different data sources. So I use two different persistence unit and I try to use

<property name="packagesToScan" value="it.two.app.domain.first" />

and

<property name="packagesToScan" value="it.two.app.domain.second" />

putting the different tables into the different packages. but It doesn't work. Infact all the table is with the first data source. then I tried to write into the perstistence XML file the name of the class like

 <persistence-unit name="persistenceFirst" transaction-type="RESOURCE_LOCAL">
 <class>it.two.app.domain.first.OneTable</class>
 <exclude-unlisted-classes/>
</persistence-unit>

and it.two.app.domain.second.OtherTable

But when I run Log says Table 'firstDB.other-table' doesn't exist and I use into the services file 

@PersistenceContext(unitName ="persistenceFirst")
private EntityManager em;

and 

@PersistenceContext(unitName = "persistenceSecond")
EntityManager em;

Have you got some Ideas? Thi is the data sources XML file

<?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:context="http://www.springframework.org/schema/context"
xmlns:jdbc="http://www.springframework.org/schema/jdbc"
xmlns:jpa="http://www.springframework.org/schema/data/jpa"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:p="http://www.springframework.org/schema/p"
xsi:schemaLocation="http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.1.xsd
    http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
    http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.0.xsd
    http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
    http://www.springframework.org/schema/context     http://www.springframework.org/schema/context/spring-context-3.1.xsd">

<!-- first datasource -->
<context:property-placeholder location="classpath:jdbc-first.properties"/>
<bean id="dataSourceFirst"  class="org.apache.commons.dbcp.BasicDataSource"
    p:driverClassName="${jdbc.driverClassName}" p:url="${jdbc.databaseurl}"
    p:username="${jdbc.username}" p:password="${jdbc.password}"  />
<!-- second datasource -->      
<context:property-placeholder location="classpath:jdbc-second.properties"/>
<bean id="dataSourceSecond"     class="org.apache.commons.dbcp.BasicDataSource"
    p:driverClassName="${jdbc.driverClassName}" p:url="${jdbc.databaseurl}"
    p:username="${jdbc.username}" p:password="${jdbc.password}"  />     


<bean id="transactionManagerFirst"  class="org.springframework.orm.jpa.JpaTransactionManager"
p:entityManagerFactory-ref="emfFirst"/>

<bean id="transactionManagerSecond"     class="org.springframework.orm.jpa.JpaTransactionManager"
p:entityManagerFactory-ref="emfSecond"/>

<tx:annotation-driven transaction-manager="transactionManagerFirst"/>
<tx:annotation-driven transaction-manager="transactionManagerSecond"/>


<jpa:repositories base-package="it.two.app.repository.first"
entity-manager-factory-ref="emfFirst" transaction-manager-ref="transactionManagerFirst" />

<jpa:repositories base-package="it.two.app.repository.second"
entity-manager-factory-ref="emfSecond" transaction-manager-ref="transactionManagerSecond" />

<bean id="emfFirst"
class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="persistenceUnitName" value="persistenceFirst"/>
<property name="persistenceXmlLocation" value="classpath:/META-INF/persistence-first.xml"/>
<property name="jpaVendorAdapter">
    <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter" />
</property>

<property name="dataSource" ref="dataSourceFirst" />
<property name="packagesToScan" value="it.two.app.domain.first" />
<property name="jpaProperties">
    <props>
        <prop     key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
        <prop key="hibernate.max_fetch_depth">3</prop>
        <prop key="hibernate.jdbc.fetch_size">50</prop>
        <prop key="hibernate.jdbc.batch_size">10</prop>
    </props>
</property>

</bean>

<bean id="emfSecond"     class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="persistenceUnitName" value="persistenceSecond"/>
<property name="persistenceXmlLocation" value="classpath:/META-INF/persistence-        second.xml"/>
<property name="jpaVendorAdapter" >
 <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"/>
</property>
<property name="dataSource" ref="dataSourceSecond"/>
<property name="packagesToScan" value="it.two.app.domain.second"/>
<property name="jpaProperties">
 <props>
<prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop> 
<prop key="hibernate.max_fetch_depth">3</prop>
<prop key="hibernate.jdbc.fetch_size">50</prop>
<prop key="hibernate.jdbc.batch_size">10</prop>
 </props>
</property>

</bean>

</beans>

SOLUTION!!!!!! I undestand the problem. Simply

<!-- first datasource -->
 <bean id="dataSourceFirst"  class="org.apache.commons.dbcp.BasicDataSource"
    p:driverClassName="com.mysql.jdbc.Driver" p:url="url...."
    p:username="username" p:password="password"  />
<!-- second datasource -->      
<bean id="dataSourceSecond"     class="org.apache.commons.dbcp.BasicDataSource"
     p:driverClassName="com.mysql.jdbc.Driver" p:url="url2...."
    p:username="username2" p:password="password2"  />

解决方案

If you would like to use multiple DataSource in Spring + JPA.

  1. Create two or more PersistenceUnit in persistence.xml.
  2. Create EntityManagerFactory for each PersistenceUnit in spring-beans.xml.

More Reference.

  1. Multiple database with Spring+Hibernate+JPA
  2. Access Multiple Database Using Spring 3, Hibernate 3
  3. Multiple Database using Spring 3.0 and Hibernate 3.0

In your DAO classes.

@PersistenceContext(unitName ="JPA_1")
private EntityManager em_1; 

@PersistenceContext(unitName ="JPA_2")
private EntityManager em_2;

Conig persistence.xml

<persistence-unit name="JPA_1" type="RESOURCE_LOCAL">
....
</persistence-unit>


<persistence-unit name="JPA_2" type="RESOURCE_LOCAL">
....
</persistence-unit>

Config : spring-beans.xml

<bean id="entityManagerFactory1" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="persistenceUnitName" value="JPA_1"/>
    <property name="jpaVendorAdapter" ref="jpaVendorAdapter"/>
    <property name="jpaDialect">
        <bean class="org.springframework.orm.jpa.vendor.EclipseLinkJpaDialect"/> <--if it is necessary, replace with hibernate.
    </property>
    <property name="jpaPropertyMap">
        <props>
            <prop key="eclipselink.weaving">false</prop> <--if it is necessary, replace with hibernate.
        </props>
    </property>
    <property name="loadTimeWeaver">
        <bean class="org.springframework.instrument.classloading.InstrumentationLoadTimeWeaver">
        </bean>
    </property>
</bean>

<bean id="entityManagerFactory2" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="persistenceUnitName" value="JPA_2"/>
    <property name="jpaVendorAdapter" ref="jpaVendorAdapter"/>
    <property name="jpaDialect">
        <bean class="org.springframework.orm.jpa.vendor.EclipseLinkJpaDialect"/> <--if it is necessary, replace with hibernate.
    </property>
    <property name="jpaPropertyMap">
        <props>
            <prop key="eclipselink.weaving">false</prop> <--if it is necessary, replace with hibernate.
        </props>
    </property>
    <property name="loadTimeWeaver">
        <bean class="org.springframework.instrument.classloading.InstrumentationLoadTimeWeaver">
        </bean>
    </property>
</bean> 

<bean id="jpaVendorAdapter" class="org.springframework.orm.jpa.vendor.EclipseLinkJpaVendorAdapter"> <--if it is necessary, replace with hibernate.
    <property name="databasePlatform" value="org.eclipse.persistence.platform.database.MySQLPlatform"/>
    <!--<property name="databasePlatform" value="org.eclipse.persistence.platform.database.OraclePlatform" />-->
    <property name="generateDdl" value="false"/>
    <property name="showSql" value="true"/>
</bean>

这篇关于春季jpa冬眠与更多的数据源的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！

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