I have a bean that uses a JNDI Connection Factory like this:
<bean id="connectionFactory" class="org.springframework.jndi.JndiObjectFactoryBean">
<property name="jndiTemplate" ref="jndiTemplate"/>
<property name="jndiName" value="SOME_NAME"/>
</bean>
<bean id="jndiTemplate" class="org.springframework.jndi.JndiTemplate">
<property name="environment">
<props>
<prop key="java.naming.factory.initial">org.ow2.carol.jndi.spi.MultiOrbInitialContextFactory</prop>
<prop key="java.naming.provider.url">rmi://some_remote_host:1091</prop>
</props>
</property>
</bean>
The fact is that this connectionFactory tries to connect to the remote host as soon as the context is loaded. The problem is that the remote service is supposed to start after the context is loaded, the context fails to load, and the application fails to deploy. Would it be possible to postpone the connection of the factory to the moment when the connection is really needed?
In other words, the connection to the connection factory is eager, and I would like it to be lazy. Is there a way to achieve this appart from subclassing the Factory and hacking around?
A bean can be made lazy-initialized with the attribute lazy-init="true"
From the documentation
A lazy-initialized bean tells the IoC container to create a bean
instance when it is first requested, rather than at startup.
Also note that this behaviour changes when the lazy-initialized bean is a dependency of a singleton bean that is not lazy-initialized.
Example configuration
<bean id="connectionFactory" class="org.springframework.jndi.JndiObjectFactoryBean" lazy-init="true">
<property name="jndiTemplate" ref="jndiTemplate" />
<property name="jndiName" value="SOME_NAME"/>
</bean>
Related
I have a simple Spring App that connects to a DB via an EntityManager
So I have to following configuration:
<bean id="domainEntityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="persistenceUnitName" value="TheManager" />
<property name="dataSource" ref="domainDataSource" />
<property name="packagesToScan" value="com.conztanz.persistence.stock.model" />
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter" />
</property>
<property name="jpaProperties">
<props>
<prop key="hibernate.hbm2ddl.auto">create-drop</prop>
<prop key="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</prop>
</props>
</property>
</bean>
<bean id="domainDataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="org.postgresql.Driver" />
<property name="url" value="jdbc:postgresql://localhost:5433/dbName" />
<property name="username" value="xxxx" />
<property name="password" value="xxxx" />
</bean>
This works fine when lunched via a main class (loading the AppContext manually)
But, once deployed into ServiceMix I get the following error :
Property 'driverClassName' threw exception; nested exception is java.lang.IllegalStateException: Could not load JDBC driver class [org.postgresql.Driver]
I've read somewhere that OSGI and DriverManager don't mix well but I fail to understand why.
The solution that seems to be a good practice is to expose the dataSource as an OSGI bundle, do you agree ? and in that case how would you have access to it from a spring context to be able to have an EntityManager for example ?
DriverManager does not work well in OSGi. The easiest way is to use a DataSource directly. Most DB drivers have such a class. If you instantiate it in your app context then it will work. The downside is though that it binds your application to the DB driver as it then will import the packages for the DataSource impl.
A more loosely coupled way is to use ops4j pax jdbc. It allows to create a DataSource as an OSGi service from a config in config admin. So in your app context you just have to add a dependency to a DataSource service. So your application is not bound to the specific DB driver. One typical use case is to use H2 in tests and oracle in production.
Working with common spring application I can define dataSource or Hibernate session factory as bean and then simply autowire them. like that:
#Autowired
private DataSource dataSource;
or
#Autowired
private SessionFactory sessionFactory;
For now I want to create some tables and store them in alfresco. How get dataSource or sessionFactory (if alfresco uses hibernate) which is pointed to alfresco database?
Inject the dataSource bean defined in core-services-context.xml:
<bean id="dataSource" class="org.alfresco.config.JndiObjectFactoryBean">
<property name="jndiName">
<value>java:comp/env/jdbc/dataSource</value>
</property>
<property name="defaultObject">
<ref bean="defaultDataSource" />
</property>
</bean>
using your-config-context.xml, for example ibatis-context.xml:
<bean id="repoSqlSessionFactory" class="org.alfresco.ibatis.HierarchicalSqlSessionFactoryBean">
<property name="resourceLoader" ref="dialectResourceLoader"/>
<property name="dataSource" ref="dataSource"/>
<property name="configLocation">
<value>classpath:alfresco/ibatis/alfresco-SqlMapConfig.xml</value>
</property>
</bean>
Be aware that:
Alfresco incorporates Hibernate and iBATIS open source database
abstraction layers to allow it to be ported to a number of different
database management systems.
so, it is preferred to use MyBatis-Spring and org.mybatis.spring.SqlSessionTemplate, for example org.alfresco.repo.domain.audit.ibatis.AuditDAOImpl.java:
<bean id="auditSqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">
<constructor-arg index="0" ref="repoSqlSessionFactory"/>
</bean>
<bean id="auditDAO" class="org.alfresco.repo.domain.audit.ibatis.AuditDAOImpl">
<property name="sqlSessionTemplate" ref="auditSqlSessionTemplate"/>
<property name="contentService" ref="contentService"/>
<property name="contentDataDAO" ref="contentDataDAO"/>
<property name="propertyValueDAO" ref="propertyValueDAO"/>
</bean>
This Alfresco 5 and Spring tutorial might be helpful for you.
We are currently using Spring 3 with hibernate 4.4 in our project.
A snippet of my database config xml looks as follows
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
destroy-method="close">
<property name="driverClass">
<value>${jdbc.driver.className}</value>
</property>
<property name="jdbcUrl">
<value>${jdbc.url}</value>
</property>
<property name="user">
<value>${jdbc.username}</value>
</property>
<property name="password">
<value>${jdbc.password}</value>
</property>
</bean>
<bean id="sessionFactory"
class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="dataSource">
<ref bean="dataSource" />
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">${jdbc.hibernate.dialect}</prop>
<prop key="hibernate.show_sql">false</prop>
<prop key="hibernate.hbm2ddl.auto">update</prop>
<prop key="hibernate.jdbc.batch_size">20</prop>
<prop key="hibernate.current_session_context_class">managed</prop>
</props>
</property>
<property name="packagesToScan" value="com.sample.entity" />
</bean>
<bean id="transactionManager"
class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="sessionFactory">
<ref bean="sessionFactory" />
</property>
</bean>
<tx:annotation-driven />
While we were testing our war , we came across this exception .
13:27:19,511 ERROR TransactionInterceptor:419 - Application exception overridden by rollback exception
org.springframework.beans.factory.BeanCreationNotAllowedException:
Error creating bean with name 'transactionManager': Singleton bean creation not allowed
while the singletons of this factory are in destruction (Do not request a bean from a
BeanFactory in a destroy method implementation!)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:212)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
at org.springframework.transaction.interceptor.TransactionAspectSupport.determineTransactionManager(TransactionAspectSupport.java:248)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:100)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
I am unable to figure out if this is because of the destroy-method =close mentioned in the config file . I am also using the #Transactional annotation at both the Service layer and the database layer . Will this cause any issue?
We were trying to test a scenario where in multiple people (around 150) are all trying to access our application at the same time.
Kindly help me out.. Please do let me know, If more details are needed.
Thanks
As the spring doc says in Section 3.6.1.5
The order of startup and shutdown invocations can be important. If a "depends-on" relationship exists between any two objects, the dependent side will start after its dependency, and it will stop before its dependency. However, at times the direct dependencies are unknown. You may only know that objects of a certain type should start prior to objects of another type. In those cases, the SmartLifecycle interface defines another option, namely the getPhase() method as defined on its super-interface, Phased.
So you need the bean to implement the SmartLifeCycle, Javadoc for SmartLifeCycle Interface 1: http://static.springsource.org/spring/docs/3.0.x/spring-framework-reference/html/beans.html#beans-factory-lifecycle-processor.
Hope this helps !!
I need to do very similar thing to what is described in Injecting Entitymanager via XML and not annnotations, but I need to inject from XML the real, container-created, entity manager, so that it behaves exactly as if there is a real #PersistenceContext annotation. I've found a LocalEntityManagerFactoryBean (notice missing "Container" word), but I'm affraid that it creates a new entity manager factory and therefore entity manager won't be compatible with that injected via real #PersistenceContext annotation.
I will describe the reason, because it is weird and maybe the solution to my problem is to choose completely different approach. I'm using PropertyPlaceholderConfigurer in my spring configuration and in this configurer I'm referencing other beans. I'm experiencing a bug that autowiring doesn't work in those referenced beans. I don't know why and how PropertyPlaceholderConfigurer turns off autowiring in those referenced beans but the fact is, that if I replace autowiring by xml configuration for those beans, everything works. But I'm unable to replace autowiring of EntityManager, since it's not standard spring bean, but jndi-loaded something I don't fully understand.
One way or the other, is there some solution?
in spring-bean.xml ,
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="persistenceUnitName" value="USER_TEST"/>
<property name="jpaVendorAdapter" ref="jpaVendorAdapter"/>
<property name="jpaDialect">
<bean class="org.springframework.orm.jpa.vendor.EclipseLinkJpaDialect"/>
</property>
<property name="jpaPropertyMap">
<props>
<prop key="eclipselink.weaving">false</prop>
</props>
</property>
<bean id="PersonDao" class="com.xxx.java.person.persistence.PersonDAO">
<property name="entityManagerFactory" ref="entityManagerFactory"/>
</bean>
<bean id="earlyInitializedApplicationSettingsService" class="...services.impl.ApplicationSettingsServiceImpl" autowire-candidate="false">
<property name="applicationSettingsDao">
<bean class="....impl.ApplicationSettingsDaoImpl">
<property name="entityManager">
<bean class="org.springframework.orm.jpa.support.SharedEntityManagerBean">
<property name="entityManagerFactory">
<bean class="org.springframework.jndi.JndiObjectFactoryBean">
<property name="jndiName" value="java:comp/env/persistence/somePersistenceUnit"/>
</bean>
</property>
</bean>
</property>
</bean>
</property>
</bean>
Notice mainly the fact, that I'm not using standard jee:jndi-lookup, because it didn't work (in the conditions created by PropertyPlaceholderConfigurer) and that was the source of my confusion. When I used direct JndiObjectFactoryBean, it worked.
Short question: If I have class that impelemnts FactoryBean interface, how can I get from FactoryBean object itself instead of FactoryBean.getObject()?
Long question: I have to use 3-rd party Spring based library which is hardly use FactoryBean interface. Right now I always must configure 2 beans:
<!-- Case 1-->
<bean id="XYZ" class="FactoryBean1" scope="prototype">
<property name="steps">
<bean class="FactoryBean2">
<property name="itemReader" ref="aName"/>
</bean>
</property>
</bean>
<bean id="aName" class="com.package.ClassName1" scope="prototype">
<property name="objectContext">
<bean class="com.package.ABC"/>
</property>
</bean>
<!-- Case 2-->
<bean id="XYZ2" class="FactoryBean1" scope="prototype">
<property name="steps">
<bean class="FactoryBean2">
<property name="itemReader" ref="aName2"/>
</bean>
</property>
</bean>
<bean id="aName2" class="com.package.ClassName1" scope="prototype">
<property name="objectContext">
<bean class="com.package.QWE"/>
</property>
</bean>
Actyually defintion of a bean with name "XYZ" (compare with "XYZ2") never will be changed, but because of factory nature I must copy the code for each configuration.
Definition of a bean with name "aName" always will be new (i.e. each configuration will have own objectContext value).
I would like to simplify the configuration have a single factory bean (remove "XYZ2" and rid of link to "aName"):
<bean id="XYZ" class="FactoryBean1" scope="prototype">
<property name="steps">
<bean class="FactoryBean2"/>
</property>
</bean>
<bean id="aName" class="com.package.ClassName1" scope="prototype">
<property name="objectContext">
<bean class="com.package.ABC"/>
</property>
</bean>
<bean id="aName2" class="com.package.ClassName1" scope="prototype">
<property name="objectContext">
<bean class="com.package.QWE"/>
</property>
</bean>
Unfortunately, it's not as simple as I expect. I suppose to glue factory (i.e. XYZ bean from the example) with necessary objects (i.e. "aName", "aName2") at runtime.
The approach doesn't work because when I ask Spring for FactoryBean object it returns to me FactoryBean.getObject() which impossible to instanciate at that time because of missing itemReader value.
I hope that SpringSource foresee my case I can somehome "hook" FactoryBean.getObject() call to provide all necessary properties at runtime.
Another complexity that disturb me a bit it's chains of Factories (Factory1 get an object from Factory2 that I have to "hook" at runtime).
Any ideas will be appreciated.
It's the & (ampersand), not the At-symbol, see Spring Framework documentation: Customizing instantiation logic using FactoryBeans
<property name="factoryBean" ref="&theFactoryBean" />
You can get the factory bean itself using the & syntax in the spring config:
<property name="factoryBean" ref="&theFactoryBean" />
as opposed to:
<property name="createdBean" ref="theFactoryBean" />