Java spring mvc 3.0.5：什么&x27；这是实例化JPA实体管理器的首选方法_Java_Spring_Jpa_Dependency Injection_Persistence

Java spring mvc 3.0.5：什么&x27；这是实例化JPA实体管理器的首选方法

java spring jpa dependency-injection

Java spring mvc 3.0.5：什么&x27；这是实例化JPA实体管理器的首选方法,java,spring,jpa,dependency-injection,persistence,Java,Spring,Jpa,Dependency Injection,Persistence,我当前的工作代码： EntityManagerFactory emf = javax.persistence.Persistence.createEntityManagerFactory("TT-SpringMVCPU"); EntityManager em = emf.createEntityManager(); 我想用这样的东西来代替它： @PersistenceContext(unitName = "TT-SpringMVCPU") private EntityManager _enti

我当前的工作代码：

EntityManagerFactory emf = javax.persistence.Persistence.createEntityManagerFactory("TT-SpringMVCPU");
EntityManager em = emf.createEntityManager();

我想用这样的东西来代替它：

@PersistenceContext(unitName = "TT-SpringMVCPU")
private EntityManager _entityManager;

当我尝试此操作时，会出现以下错误：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'showController': Injection of persistence dependencies failed; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'TT-SpringMVCPU' is defined
    org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor.postProcessPropertyValues(PersistenceAnnotationBeanPostProcessor.java:341)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1074)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517)
...

我忘记配置什么了？

来自Spring参考手册：

我忘记配置什么了

好吧，你什么都没展示：）总之，展示了一种做事的方式：

配置

LocalEnityManagerFactoryBean

创建

EntityManagerFactory

```
JpaTransactionManager
```
管理JPA事务
告诉Spring查找
```
@Transactional
```
你的豆定义

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

    <bean id="entityManagerFactory"
        class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean" />

    <bean id="productDaoImpl" class="product.ProductDaoImpl"/>

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

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

    <tx:annotation-driven />

</beans>

就这样。二注四 bean定义

看一看

另见

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

    <bean id="entityManagerFactory"
        class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean" />

    <bean id="productDaoImpl" class="product.ProductDaoImpl"/>

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

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

    <tx:annotation-driven />

</beans>

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

    <bean id="entityManagerFactory"
        class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean" />

    <bean id="productDaoImpl" class="product.ProductDaoImpl"/>

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

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

    <tx:annotation-driven />

</beans>

我忘记配置什么了

好吧，你什么都没展示：）总之，展示了一种做事的方式：

配置

LocalEnityManagerFactoryBean

创建

EntityManagerFactory

```
JpaTransactionManager
```
管理JPA事务
告诉Spring查找
```
@Transactional
```
你的豆定义

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

    <bean id="entityManagerFactory"
        class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean" />

    <bean id="productDaoImpl" class="product.ProductDaoImpl"/>

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

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

    <tx:annotation-driven />

</beans>

就这样。二注四 bean定义

看一看

另见

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

    <bean id="entityManagerFactory"
        class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean" />

    <bean id="productDaoImpl" class="product.ProductDaoImpl"/>

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

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

    <tx:annotation-driven />

</beans>

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

    <bean id="entityManagerFactory"
        class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean" />

    <bean id="productDaoImpl" class="product.ProductDaoImpl"/>

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

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

    <tx:annotation-driven />

</beans>