使用Spring + Hibernate的多租户：“为多租户配置了SessionFactory，但未指定租户标识符”
问题内容：
在Spring 3应用程序中，我试图通过Hibernate
4的本机MultiTenantConnectionProvider和CurrentTenantIdentifierResolver实现多租户。我发现在Hibernate
4.1.3
中存在此问题，但是我正在运行4.1.9并仍收到类似的异常：
Caused by:
org.hibernate.HibernateException: SessionFactory configured for multi-tenancy, but no tenant identifier specified
at org.hibernate.internal.AbstractSessionImpl.<init>(AbstractSessionImpl.java:84)
at org.hibernate.internal.SessionImpl.<init>(SessionImpl.java:239)
at org.hibernate.internal.SessionFactoryImpl$SessionBuilderImpl.openSession(SessionFactoryImpl.java:1597)
at org.hibernate.internal.SessionFactoryImpl.openSession(SessionFactoryImpl.java:963)
at org.springframework.orm.hibernate4.HibernateTransactionManager.doBegin(HibernateTransactionManager.java:328)
at org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction(AbstractPlatformTransactionManager.java:371)
at org.springframework.transaction.interceptor.TransactionAspectSupport.createTransactionIfNecessary(TransactionAspectSupport.java:334)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:105)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:631)
at com.afflatus.edu.thoth.repository.UserRepository$$EnhancerByCGLIB$$c844ce96.getAllUsers(<generated>)
at com.afflatus.edu.thoth.service.UserService.getAllUsers(UserService.java:29)
at com.afflatus.edu.thoth.HomeController.hello(HomeController.java:37)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:219)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:746)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:687)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:925)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:915)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:811)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:735)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:796)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:848)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:671)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:448)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:138)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:564)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:213)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1070)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:375)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:175)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1004)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:136)
at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:258)
at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:109)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
at org.eclipse.jetty.server.Server.handle(Server.java:439)
at org.eclipse.jetty.server.HttpChannel.run(HttpChannel.java:246)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:265)
at org.eclipse.jetty.io.AbstractConnection$ReadCallback.run(AbstractConnection.java:240)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:589)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:520)
at java.lang.Thread.run(Thread.java:722) enter code here
以下是相关代码。在MultiTenantConnectionProviderI中，我现在只写了一些简单的代码，每次都只返回一个新的连接，并且CurrentTenantIdentifierResolver在这一点上总是返回相同的ID。显然，在我设法实例化连接之后，将实施此逻辑。
config.xml
<bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="packagesToScan">
<list>
<value>com.afflatus.edu.thoth.entity</value>
</list>
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">${hibernate.dialect}</prop>
<prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
<prop key="hibernate.hbm2ddl">${hibernate.dbm2ddl}</prop>
<prop key="hibernate.multiTenancy">DATABASE</prop>
<prop key="hibernate.multi_tenant_connection_provider">com.afflatus.edu.thoth.connection.MultiTenantConnectionProviderImpl</prop>
<prop key="hibernate.tenant_identifier_resolver">com.afflatus.edu.thoth.context.MultiTenantIdentifierResolverImpl</prop>
</props>
</property>
</bean>
<bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="autodetectDataSource" value="false" />
<property name="sessionFactory" ref="sessionFactory" />
</bean>
MultiTenantConnectionProvider.java
package com.afflatus.edu.thoth.connection;
import java.util.Properties;
import java.util.HashMap;
import java.util.Map;
import org.hibernate.service.jdbc.connections.spi.AbstractMultiTenantConnectionProvider;
import org.hibernate.service.jdbc.connections.spi.ConnectionProvider;
import org.hibernate.ejb.connection.InjectedDataSourceConnectionProvider;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
import org.hibernate.cfg.*;
public class MultiTenantConnectionProviderImpl extends AbstractMultiTenantConnectionProvider {
private final Map<String, ConnectionProvider> connectionProviders
= new HashMap<String, ConnectionProvider>();
@Override
protected ConnectionProvider getAnyConnectionProvider() {
System.out.println("barfoo");
Properties properties = getConnectionProperties();
DriverManagerDataSource ds = new DriverManagerDataSource();
ds.setDriverClassName("com.mysql.jdbc.Driver");
ds.setUrl("jdbc:mysql://127.0.0.1:3306/test");
ds.setUsername("root");
ds.setPassword("");
InjectedDataSourceConnectionProvider defaultProvider = new InjectedDataSourceConnectionProvider();
defaultProvider.setDataSource(ds);
defaultProvider.configure(properties);
return (ConnectionProvider) defaultProvider;
}
@Override
protected ConnectionProvider selectConnectionProvider(String tenantIdentifier) {
System.out.println("foobar");
Properties properties = getConnectionProperties();
DriverManagerDataSource ds = new DriverManagerDataSource();
ds.setDriverClassName("com.mysql.jdbc.Driver");
ds.setUrl("jdbc:mysql://127.0.0.1:3306/test2");
ds.setUsername("root");
ds.setPassword("");
InjectedDataSourceConnectionProvider defaultProvider = new InjectedDataSourceConnectionProvider();
defaultProvider.setDataSource(ds);
defaultProvider.configure(properties);
return (ConnectionProvider) defaultProvider;
}
private Properties getConnectionProperties() {
Properties properties = new Properties();
properties.put(AvailableSettings.DIALECT, "org.hibernate.dialect.MySQLDialect");
properties.put(AvailableSettings.DRIVER, "com.mysql.jdbc.Driver");
properties.put(AvailableSettings.URL, "jdbc:mysql://127.0.0.1:3306/test");
properties.put(AvailableSettings.USER, "root");
properties.put(AvailableSettings.PASS, "");
return properties;
}
}
CurrentTenantIdentifierResolver.java
package com.afflatus.edu.thoth.context;
import org.hibernate.context.spi.CurrentTenantIdentifierResolver;
public class CurrentTenantIdentifierResolverImpl implements CurrentTenantIdentifierResolver {
public String resolveCurrentTenantIdentifier() {
return "1";
}
public boolean validateExistingCurrentSessions() {
return true;
}
}
有人能看到特别明显的错误吗？一旦打开事务，这将引发异常。它 看起来
像SessionFactory没有被正确打开会话，或者Session是简单地忽略了由返回的值CurrentTenantIdentifierResolver，我相信是在Hibernate中4.1.3的问题;
这应该已经解决了。
问题答案：
前瞻性：尽管我接受了（将）包含代码的答案，但如果您认为这很有用，请提高Darren的答案。他是我完全能够解决此问题的原因。
好吧，我们开始....
正如Darren所指出的，这确实是SessionFactory错误地实例化Session的问题。如果要手动实例化会话，则没有问题。例如：
sessionFactory.withOptions().tenantIdentifier(tenant).openSession();
但是，@Transactional注释会导致SessionFactory使用打开会话sessionFactory.getCurrentSession()，这不会从中拉出租户标识符CurrentTenantIdentifierResolver。
Darren建议在DAO层中手动打开Session，但这意味着每种DAO方法都将具有本地范围的事务。更好的方法是在服务层上。每个服务层调用（即doSomeLogicalTask()）可以调用多个DAO方法。有意义的是，每个逻辑上都应绑定到同一事务。
此外，我不喜欢在每个服务层方法中复制代码来创建和管理事务的想法。相反，我使用AOP将每个方法包装在服务层中，并带有实例化新方法Session和处理事务的建议。方面将电流存储Session在TheadLocal堆栈中，DAO层可以访问该堆栈以进行查询。
所有这些工作将使接口和实现与错误修复的接口和实现保持相同，除了DAO超类中的一行Session将从ThreadLocal堆栈中获取而不是从中获取SessionFactory。漏洞修复后即可更改。
稍作清理后，我将很快发布代码。如果有人对此有任何疑问，请随时在下面进行讨论。
