java - 配置hibernate jpa和spring mvc(entityManager始终为null)

Question

早上好，我对 hibernate jpa 和 spring 还很陌生，这是我制作的第一个项目，每次我尝试执行它时，我都会得到 npe。这是我的代码

applicationContext.xml

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="dao" class="com.talan.springmvc.dao.AdminDaoImpl">
</bean>


<bean id="metier" class="com.talan.springmvc.metier.AdminMetier">
    <property name="dao" ref="dao" />
</bean>
<bean id="datasource"
    class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="oracle.jdbc.driver.OracleDriver"></property>
    <property name="url" value="jdbc:oracle:thin:@localhost:1521/XE"></property>
    <property name="username" value="system"></property>
    <property name="password" value="Islem1992"></property>

</bean>
<bean id="persistenceUnitManager"
    class="org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager">
    <property name="persistenceXmlLocations">
        <list>
            <value>classpath*:META-INF/persistence.xml</value>
        </list>
    </property>
    <property name="defaultDataSource" ref="datasource"></property>
</bean>
<bean id="entityManagerFactory
    class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="persistenceUnitManager" ref="persistenceUnitManager"></property>
    <property name="dataSource" ref="datasource" />
    <property name="persistenceUnitName" value="myapp"></property>
    <property name="jpaProperties">
        <props>
            <prop key="hibernate.hbm2ddl.auto">none</prop>
            <prop key="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</prop>
        </props>
    </property>
    <property name="jpaVendorAdapter">
        <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
        </bean>
    </property>
</bean>
<!-- <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean"> 
    <property name="persistenceUnitName" value="myapp"></property> </bean> -->
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
    <property name="entityManagerFactory" ref="entityManagerFactory"></property>
</bean>
<tx:annotation-driven transaction-manager="transactionManager" />

持久性.xml

<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="myapp"
        transaction-type="RESOURCE_LOCAL">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
    </persistence-unit>
</persistence>

测试.java

封装测试；

import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.talan.springmvc.entities.Agence;
import com.talan.springmvc.entities.User;
import com.talan.springmvc.metier.IAdminMetier;

public class Test {
    public static void main(String[] args){

        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(new String[]{"applicationContext.xml"});
        IAdminMetier admin = (IAdminMetier) context.getBean("metier");
        User u = new User(1,"islem", "yeddes", "salesAgent");
        admin.addUser(u);
    }

}

Answer 1

我忘记发布我的 DAO

package com.talan.springmvc.dao;

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

import com.talan.springmvc.entities.User;

public class AdminDaoImpl implements IAdminDao {
    @PersistenceContext
    private EntityManager em;
    @Override
    public User addUser(User  u) {
        em.persist(u);
        return u;
    }   



}