使用 Spring+Hibernate+JPA 的多数据库

Question

我正在尝试配置 Spring+Hibernate+JPA 以使用两个数据库（MySQL 和 MSSQL）。

我的 datasource-context.xml：

<?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"
 xsi:schemaLocation="http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd
  http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-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/util http://www.springframework.org/schema/util/spring-util-2.5.xsd"
 xmlns:p="http://www.springframework.org/schema/p" xmlns:tx="http://www.springframework.org/schema/tx"
 xmlns:util="http://www.springframework.org/schema/util">

 <!--
 Data Source config 
  -->
 <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
  destroy-method="close" p:driverClassName="${local.jdbc.driver}" p:url="${local.jdbc.url}"
  p:username="${local.jdbc.username}" p:password="${local.jdbc.password}">
 </bean>

 <bean id="dataSourceRemote" class="org.apache.commons.dbcp.BasicDataSource"
  destroy-method="close" p:driverClassName="${remote.jdbc.driver}"
  p:url="${remote.jdbc.url}" p:username="${remote.jdbc.username}"
  p:password="${remote.jdbc.password}" />

 <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager"
  p:entity-manager-factory-ref="entityManagerFactory" />

 <!-- 
    JPA config   
    -->
 <tx:annotation-driven transaction-manager="transactionManager" />

 <bean id="persistenceUnitManager"
  class="org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager">
        <property name="persistenceXmlLocations">
   <list value-type="java.lang.String">
    <value>classpath*:config/persistence.local.xml</value>
    <value>classpath*:config/persistence.remote.xml</value>
   </list>
  </property>

  <property name="dataSources">
   <map>
    <entry key="localDataSource" value-ref="dataSource" />
    <entry key="remoteDataSource" value-ref="dataSourceRemote" />
   </map>
  </property>
  <property name="defaultDataSource" ref="dataSource" />
 </bean>

 <bean id="entityManagerFactory"
  class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
  <property name="jpaVendorAdapter">
   <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"
    p:showSql="true" p:generateDdl="true">
   </bean>
  </property>
  <property name="persistenceUnitManager" ref="persistenceUnitManager" />
<property name="persistenceUnitName" value="localjpa"/>
 </bean>

 <bean
  class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />

</beans>

每个 persistence.xml 包含一个单元，如下所示：

<persistence-unit name="remote" transaction-type="RESOURCE_LOCAL">
  <properties>
   <property name="hibernate.ejb.naming_strategy" value="org.hibernate.cfg.DefaultNamingStrategy" />
   <property name="hibernate.dialect" value="${remote.hibernate.dialect}" />
   <property name="hibernate.hbm2ddl.auto" value="${remote.hibernate.hbm2ddl.auto}" />
  </properties>
 </persistence-unit>

PersistenceUnitManager 导致以下异常：

无法解析对 bean 的引用 设置时的“persistenceUnitManager” 豆属性 '持久性单元管理器';嵌套的 例外是 org.springframework.beans.factory.BeanCreationException： 使用名称创建 bean 时出错 'persistenceUnitManager' 定义于 类路径资源 [配置/datasource-context.xml]： bean 初始化失败；嵌套的 例外是 org.springframework.beans.TypeMismatchException： 无法转换属性值 输入 [java.util.ArrayList] 为必填项 为属性输入 [java.lang.String] 'persistenceXmlLocation';嵌套的 例外是 java.lang.IllegalArgumentException： 无法转换类型值 [java.util.ArrayList] 为所需类型 [java.lang.String] 属性 “persistenceXmlLocation”：没有匹配 找到编辑器或转换策略

如果只留下一个 persistence.xml 没有列表，则每个都可以正常工作 但我需要 2 个单元...

我还尝试寻找在 Spring+Hibernate 上下文中使用两个数据库的替代解决方案，所以我将不胜感激任何解决方案。

更改为 persistenceXmlLocations 后出现新错误：

{classpath:config/persistence.local.xml, classpath:config/persistence.remote.xml} 中没有定义单个默认持久性单元

更新：

我添加 persistenceUnitName，它可以工作，但只能使用一个单元，仍然需要帮助。

更新：

我更改了配置文件： datasource-context.xml

<?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"
    xsi:schemaLocation="http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-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/util http://www.springframework.org/schema/util/spring-util-2.5.xsd"
    xmlns:p="http://www.springframework.org/schema/p" xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:util="http://www.springframework.org/schema/util">

    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
        destroy-method="close" p:driverClassName="${local.jdbc.driver}" p:url="${local.jdbc.url}"
        p:username="${local.jdbc.username}" p:password="${local.jdbc.password}">
    </bean>

    <bean id="dataSourceRemote" class="org.apache.commons.dbcp.BasicDataSource"
        destroy-method="close" p:driverClassName="${remote.jdbc.driver}"
        p:url="${remote.jdbc.url}" p:username="${remote.jdbc.username}"
        p:password="${remote.jdbc.password}">
    </bean>

    <bean
        class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor">
        <property name="defaultPersistenceUnitName" value="pu1" />
    </bean>

    <bean id="persistenceUnitManager"
        class="org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager">
        <property name="persistenceXmlLocation" value="${persistence.xml.location}" />
        <property name="defaultDataSource" ref="dataSource" /> <!-- problem -->
        <property name="dataSources">
            <map>
                <entry key="local" value-ref="dataSource" />
                <entry key="remote" value-ref="dataSourceRemote" />
            </map>
        </property>
    </bean>

    <bean id="entityManagerFactory"
        class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="jpaVendorAdapter">
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"
                p:showSql="true" p:generateDdl="true">
            </bean>
        </property>
        <property name="persistenceUnitManager" ref="persistenceUnitManager" />
        <property name="persistenceUnitName" value="pu1" />
        <property name="dataSource" ref="dataSource" />
    </bean>

    <bean id="entityManagerFactoryRemote"
        class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="jpaVendorAdapter">
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"
                p:showSql="true" p:generateDdl="true">
            </bean>
        </property>
        <property name="persistenceUnitManager" ref="persistenceUnitManager" />
        <property name="persistenceUnitName" value="pu2" />
        <property name="dataSource" ref="dataSourceRemote" />
    </bean>

    <tx:annotation-driven />

    <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager"
        p:entity-manager-factory-ref="entityManagerFactory" />


    <bean id="transactionManagerRemote" class="org.springframework.orm.jpa.JpaTransactionManager"
        p:entity-manager-factory-ref="entityManagerFactoryRemote" />

</beans>

persistence.xml

<?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="pu1" transaction-type="RESOURCE_LOCAL">
        <properties>
            <property name="hibernate.ejb.naming_strategy" value="org.hibernate.cfg.DefaultNamingStrategy" />
            <property name="hibernate.dialect" value="${local.hibernate.dialect}" />
            <property name="hibernate.hbm2ddl.auto" value="${local.hibernate.hbm2ddl.auto}" />                          
        </properties>
    </persistence-unit>

    <persistence-unit name="pu2" transaction-type="RESOURCE_LOCAL">
        <properties>
            <property name="hibernate.ejb.naming_strategy" value="org.hibernate.cfg.DefaultNamingStrategy" />
            <property name="hibernate.dialect" value="${remote.hibernate.dialect}" />
            <property name="hibernate.hbm2ddl.auto" value="${remote.hibernate.hbm2ddl.auto}" />
        </properties>
    </persistence-unit>

</persistence>

现在它构建了两个entityManagerFactory，但两者都是针对Microsoft SQL Server的

[main] INFO org.hibernate.ejb.Ejb3Configuration - Processing PersistenceUnitInfo [
    name: pu1
    ...]
[main] INFO org.hibernate.cfg.SettingsFactory - RDBMS: Microsoft SQL Server

[main] INFO org.hibernate.ejb.Ejb3Configuration - Processing PersistenceUnitInfo [
    name: pu2
    ...]
[main] INFO org.hibernate.cfg.SettingsFactory - RDBMS: Microsoft SQL Server (but must MySQL)

，我建议仅使用dataSource，dataSourceRemote（无替换）不起作用。这是我的最后一个问题。

Answer 1

您需要使用persistenceXmlLocations属性（注意复数）而不是persistenceXmlLocation。它是一个字符串数组，因此它将从列表自动转换：

<bean id="persistenceUnitManager"
      class="org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager">
  <property name="persistenceXmlLocations"><list>
    <value>classpath*:config/persistence.local.xml</value>
    <value>classpath*:config/persistence.remote.xml</value>
  </list></property>
  ...

更新（基于编辑）

您的entityManagerFactory未指定persistenceUnitName属性。您必须明确地这样做，因为您定义了多个持久性单元，而 entityManagerFactory 必须知道要使用哪一个。

Answer 2

Justin，第 3 点可以用更标准的方式完成，如下所示：

1. 在 Spring 上下文中：

   <上下文:annotation-config />
   

2. 在 Spring 管理的 DAO 中（注意 unitName 属性）：

   @PersistenceContext(unitName = "pu1"`) protected EntityManagerEntityManager;
   

这样，与名为“pu1”的持久性单元相对应的正确实例化的EntityManager将被注入到相应的DAO中。

Answer 3

如果您遵循本教程，
http://www.javacodegeeks.com/ 2010/05/jboss-42x-spring-3-jpa-hibernate.html 您可以进行以下更改来访问两个不同的数据库：

1. persistence.xml，为第二个数据库定义第二个持久性单元。
2. spring.xml，以不同的名称定义第二个entityManagerFactory bean，假设“entityManagerFactoryDB2”并将其配置为使用第二个数据库的持久单元。

3. 对于您想要访问第二个数据库的每个 DAO，包括以下内容：

   <前><代码>@Autowired
   私有EntityManagerFactoryEntityManagerFactoryDB2；

   @PostConstruct
   公共无效初始化（）{
   super.setEntityManagerFactory(entityManagerFactoryDB2);
   }

仅此而已！

在 Spring 服务类上，像往常一样使用 DAO！

Answer 4

我以这种方式解决了问题（如何使用 spring 和 Hibernate 连接多个数据库），我希望它会有所帮助:)
注意： 我已经添加了相关代码，请借助我在下面提到的代码中使用的 impl 来制作 dao。

**web.xml**

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
    id="WebApp_ID" version="3.0">
    <display-name>MultipleDatabaseConnectivityInSpring</display-name>
    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>
     <servlet>
        <servlet-name>dispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
         <load-on-startup>1</load-on-startup>
    </servlet>
     <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener> 
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>
            /WEB-INF/dispatcher-servlet.xml
        </param-value>
    </context-param>
    <servlet-mapping>
        <servlet-name>dispatcher</servlet-name>
        <url-pattern>*.htm</url-pattern>
    </servlet-mapping>
    <session-config>
        <session-timeout>30</session-timeout>
    </session-config>
</web-app>


**persistence.xml**


<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0"
    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">
    <persistence-unit name="localPersistenceUnitOne"
        transaction-type="RESOURCE_LOCAL">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <class>in.india.entities.CustomerDetails</class>
        <exclude-unlisted-classes />
        <properties>
            <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect" />
            <property name="hibernate.connection.driver_class" value="org.postgresql.Driver" />
            <property name="hibernate.jdbc.batch_size" value="0" />
            <property name="hibernate.show_sql" value="false" />
            <property name="hibernate.connection.url" value="jdbc:postgresql://localhost:5432/shankar?sslmode=require" />
            <property name="hibernate.connection.username" value="username" />
            <property name="hibernate.connection.password" value="password" />
            <property name="hibernate.hbm2ddl.auto" value="update" />
        </properties>
    </persistence-unit>
    <persistence-unit name="localPersistenceUnitTwo"
        transaction-type="RESOURCE_LOCAL">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <class>in.india.entities.CompanyDetails</class>
        <exclude-unlisted-classes />
        <properties>
            <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect" />
            <property name="hibernate.connection.driver_class" value="org.postgresql.Driver" />
            <property name="hibernate.jdbc.batch_size" value="0" />
            <property name="hibernate.show_sql" value="false" />
            <property name="hibernate.connection.url" value="jdbc:postgresql://localhost:5432/shankarTwo?sslmode=require" />
            <property name="hibernate.connection.username" value="username" />
            <property name="hibernate.connection.password" value="password" />
            <property name="hibernate.hbm2ddl.auto" value="update" />
        </properties>
    </persistence-unit>
</persistence>


**dispatcher-servlet**


<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:task="http://www.springframework.org/schema/task" xmlns:p="http://www.springframework.org/schema/p"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:util="http://www.springframework.org/schema/util"
    default-autowire="byName"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd 
      http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd  
      http://www.springframework.org/schema/aop  http://www.springframework.org/schema/aop/spring-aop-3.0.xsd 
      http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-3.0.xsd
      http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd http://www.springframework.org/schema/mvc 
      http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">
    <!-- Configure messageSource -->

    <mvc:annotation-driven />
    <context:component-scan base-package="in.india.*" />
    <bean id="messageResource"
        class="org.springframework.context.support.ResourceBundleMessageSource"
        autowire="byName">
        <property name="basename" value="messageResource"></property>
    </bean>

    <bean
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix">
            <value>/WEB-INF/jsp/</value>
        </property>
        <property name="suffix">
            <value>.jsp</value>
        </property>
    </bean>



    <bean id="entityManagerFactoryOne"
        class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"
        autowire="constructor">
        <property name="persistenceUnitName" value="localPersistenceUnitOne" />
    </bean>

    <bean id="messageSource"
        class="org.springframework.context.support.ResourceBundleMessageSource"
        autowire="byName">
        <property name="basename" value="messageResource" />
    </bean>

    <bean id="entityManagerFactoryTwo"
        class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"
        autowire="constructor">
        <property name="persistenceUnitName" value="localPersistenceUnitTwo" />
    </bean>

    <bean id="manager1" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactoryOne" />
    </bean>

    <bean id="manager2" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactoryTwo" />
    </bean>

    <tx:annotation-driven transaction-manager="manager1" />
    <tx:annotation-driven transaction-manager="manager2" />

    <!-- declare dependies here -->

    <bean class="in.india.service.dao.impl.CustomerServiceImpl" />
    <bean class="in.india.service.dao.impl.CompanyServiceImpl" />

    <!-- Configure MVC annotations -->
    <bean
        class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping" />
    <bean
        class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter" />
    <bean
        class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter" />
</beans>



**java class to persist into one database**


package in.india.service.dao.impl;

import in.india.entities.CompanyDetails;
import in.india.service.CompanyService;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

import org.springframework.transaction.annotation.Transactional;

public class CompanyServiceImpl implements CompanyService {

    @PersistenceContext(unitName = "entityManagerFactoryTwo")
    EntityManager entityManager;

    @Transactional("manager2")
    @Override
    public boolean companyService(CompanyDetails companyDetails) {

        boolean flag = false;
        try 
        {
            entityManager.persist(companyDetails);
            flag = true;
        } 
        catch (Exception e)
        {
            flag = false;
        }

        return flag;
    }

}


**java class to persist in another database** 

package in.india.service.dao.impl;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

import org.springframework.transaction.annotation.Transactional;

import in.india.entities.CustomerDetails;
import in.india.service.CustomerService;

public class CustomerServiceImpl implements CustomerService {

    @PersistenceContext(unitName = "localPersistenceUnitOne")
    EntityManager entityManager;

    @Override
    @Transactional(value = "manager1")
    public boolean customerService(CustomerDetails companyData) {

        boolean flag = false;
        entityManager.persist(companyData);
        return flag;
    }
}


**customer.jsp**

<%@page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<%@taglib uri="http://www.springframework.org/tags/form" prefix="form"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
    <center>
        <h1>SpringWithMultipleDatabase's</h1>
    </center>
    <form:form method="GET" action="addCustomer.htm"  modelAttribute="customerBean" >
        <table>
            <tr>
                <td><form:label path="firstName">First Name</form:label></td>
                <td><form:input path="firstName" /></td>
            </tr>
            <tr>
                <td><form:label path="lastName">Last Name</form:label></td>
                <td><form:input path="lastName" /></td>
            </tr>
            <tr>
                <td><form:label path="emailId">Email Id</form:label></td>
                <td><form:input path="emailId" /></td>
            </tr>
            <tr>
                <td><form:label path="profession">Profession</form:label></td>
                <td><form:input path="profession" /></td>
            </tr>
            <tr>
                <td><form:label path="address">Address</form:label></td>
                <td><form:input path="address" /></td>
            </tr>
            <tr>
                <td><form:label path="age">Age</form:label></td>
                <td><form:input path="age" /></td>
            </tr>
            <tr>
                <td><input type="submit" value="Submit"/></td>
             </tr>
        </table>
    </form:form>
</body>
</html>


**company.jsp**


<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%>
<%@taglib uri="http://www.springframework.org/tags/form" prefix="form"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>ScheduleJobs</title>
</head>
<body>
 <center><h1>SpringWithMultipleDatabase's</h1></center>
 <form:form method="GET" action="addCompany.htm"  modelAttribute="companyBean" >
 <table>
    <tr>
        <td><form:label path="companyName">Company Name</form:label></td>
        <td><form:input path="companyName" /></td>
    </tr>
    <tr>
        <td><form:label path="companyStrength">Company Strength</form:label></td>
        <td><form:input path="companyStrength" /></td>
    </tr>
    <tr>
        <td><form:label path="companyLocation">Company Location</form:label></td>
        <td><form:input path="companyLocation" /></td>
    </tr>
     <tr>
        <td>
            <input type="submit" value="Submit"/>
        </td>
    </tr>
 </table>
 </form:form>
</body>
</html>

**index.jsp**

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Home</title>
</head>
<body>
 <center><h1>Multiple Database Connectivity In Spring sdfsdsd</h1></center>

<a href='customerRequest.htm'>Click here to go on Customer page</a>
<br>
<a href='companyRequest.htm'>Click here to go on Company page</a>
</body>
</html>

**success.jsp**

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>ScheduleJobs</title>
</head>
<body>
 <center><h1>SpringWithMultipleDatabase</h1></center>
    <b>Successfully Saved</b>
</body>
</html>

**CompanyController**

package in.india.controller;

import in.india.bean.CompanyBean;
import in.india.entities.CompanyDetails;
import in.india.service.CompanyService;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;

@Controller
public class CompanyController {

    @Autowired
    CompanyService companyService;

    @RequestMapping(value = "/companyRequest.htm", method = RequestMethod.GET)
    public ModelAndView addStudent(ModelMap model) {
        CompanyBean companyBean = new CompanyBean();
        model.addAttribute(companyBean);
        return new ModelAndView("company");
    }

    @RequestMapping(value = "/addCompany.htm", method = RequestMethod.GET)
    public ModelAndView companyController(@ModelAttribute("companyBean") CompanyBean companyBean, Model model) {
        CompanyDetails  companyDetails = new CompanyDetails();
        companyDetails.setCompanyLocation(companyBean.getCompanyLocation());
        companyDetails.setCompanyName(companyBean.getCompanyName());
        companyDetails.setCompanyStrength(companyBean.getCompanyStrength());
        companyService.companyService(companyDetails);
        return new ModelAndView("success");

    }
}

**CustomerController**


package in.india.controller;

import in.india.bean.CustomerBean;
import in.india.entities.CustomerDetails;
import in.india.service.CustomerService;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;

@Controller
public class CustomerController {

    @Autowired
    CustomerService customerService;

    @RequestMapping(value = "/customerRequest.htm", method = RequestMethod.GET)
    public ModelAndView addStudent(ModelMap model) {
        CustomerBean customerBean = new CustomerBean();
        model.addAttribute(customerBean);
        return new ModelAndView("customer");
    }

    @RequestMapping(value = "/addCustomer.htm", method = RequestMethod.GET)
    public ModelAndView customerController(@ModelAttribute("customerBean") CustomerBean customer, Model model) {
        CustomerDetails customerDetails = new CustomerDetails();
        customerDetails.setAddress(customer.getAddress());
        customerDetails.setAge(customer.getAge());
        customerDetails.setEmailId(customer.getEmailId());
        customerDetails.setFirstName(customer.getFirstName());
        customerDetails.setLastName(customer.getLastName());
        customerDetails.setProfession(customer.getProfession());
        customerService.customerService(customerDetails);
        return new ModelAndView("success");

    }
}


**CompanyDetails Entity**


package in.india.entities;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.SequenceGenerator;
import javax.persistence.Table;

@Entity
@Table(name = "company_details")
public class CompanyDetails {

    @Id
    @SequenceGenerator(name = "company_details_seq", sequenceName = "company_details_seq", initialValue = 1, allocationSize = 1)
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "company_details_seq")
    @Column(name = "company_details_id")
    private Long companyDetailsId;
    @Column(name = "company_name")
    private String companyName;
    @Column(name = "company_strength")
    private Long companyStrength;
    @Column(name = "company_location")
    private String companyLocation;

    public Long getCompanyDetailsId() {
        return companyDetailsId;
    }

    public void setCompanyDetailsId(Long companyDetailsId) {
        this.companyDetailsId = companyDetailsId;
    }

    public String getCompanyName() {
        return companyName;
    }

    public void setCompanyName(String companyName) {
        this.companyName = companyName;
    }

    public Long getCompanyStrength() {
        return companyStrength;
    }

    public void setCompanyStrength(Long companyStrength) {
        this.companyStrength = companyStrength;
    }

    public String getCompanyLocation() {
        return companyLocation;
    }

    public void setCompanyLocation(String companyLocation) {
        this.companyLocation = companyLocation;
    }
}


**CustomerDetails Entity**

package in.india.entities;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.SequenceGenerator;
import javax.persistence.Table;

@Entity
@Table(name = "customer_details")
public class CustomerDetails {

    @Id
    @SequenceGenerator(name = "customer_details_seq", sequenceName = "customer_details_seq", initialValue = 1, allocationSize = 1)
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "customer_details_seq")
    @Column(name = "customer_details_id")
    private Long customerDetailsId;
    @Column(name = "first_name ")
    private String firstName;
    @Column(name = "last_name ")
    private String lastName;
    @Column(name = "email_id")
    private String emailId;
    @Column(name = "profession")
    private String profession;
    @Column(name = "address")
    private String address;
    @Column(name = "age")
    private int age;
    public Long getCustomerDetailsId() {
        return customerDetailsId;
    }

    public void setCustomerDetailsId(Long customerDetailsId) {
        this.customerDetailsId = customerDetailsId;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getEmailId() {
        return emailId;
    }

    public void setEmailId(String emailId) {
        this.emailId = emailId;
    }

    public String getProfession() {
        return profession;
    }

    public void setProfession(String profession) {
        this.profession = profession;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}

Answer 5

查看此 Wiki 页面 http://code.google.com/p /gwt-spring-jpa-lucene/wiki/PersistenceUnitSetup 详细介绍了如何使用 persistenceXmlLocations 和 DAO 中的注释来配置 spring

Answer 6

1. 创建与每个持久单元相对应的多个entityManagerFactory。
2. 指定@PersistenceContext的unitName属性

在那些将被注入的entityManagerFactories之间切换