我是春天的初学者,我在春天有一个dao类。但注释@auto wired或@ service无法正常工作,我通过在应用程序上下文中创建bean来解决问题,注释不是什么原因在春天工作。提供" context:component-scan base-package ="但是注释也没有用
StudentDao
public interface StudentDao {
public int addStudent(StudentEntity s);
}
-----------------------------------
@Service("studentDaoImpl")
public class StudentDaoImpl implements StudentDao{
@PersistenceContext
private EntityManager em;
@Override
@Transactional
public int addStudent(StudentEntity student) {
// TODO Auto-generated method stub
em.persist(student);
return student.getId();
}
}
------------------------------------------------
FascadeDaoImpl
public class FascadeControllerImpl implements FascadeController {
// @Autowired
private StudentDao studentDao;
private UserContext uc;
public void studentDao() {
studentDao=(StudentDao) uc.getContext().getBean("studentDao");
}
}
public int addStudent(StudentEntity student) {
studentDao();
return studentDao.addStudent(student);
}
的ApplicationContext
<?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:p="http://www.springframework.org/schema/p"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-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/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd">
<context:component-scan base-package="sms.spring.dao" />
<context:component-scan base-package="sms.spring.fascade" />
<context:component-scan base-package="sms.spring.entity" />
<context:annotation-config />
<bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor"/>
<bean class="sms.spring.entity.StudentEntity" id="studentbean"/>
<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName">
<value>com.microsoft.sqlserver.jdbc.SQLServerDriver</value>
</property>
<property name="url">
<value>jdbc:sqlserver://localhost;databaseName=dbstsms</value>
</property>
<property name="username">
<value>sa</value>
</property>
<property name="password">
<value>sa123</value>
</property>
</bean>
<bean id="entityManagerFactory"
class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="persistenceXmlLocation" value="classpath:META-INF/persistence.xml" />
<property name="persistenceUnitName" value="PERSUnit" />
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter" />
</property>
<property name="jpaProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.SQLServer2008Dialect</prop>
<prop key="hibernate.show_sql">true</prop>
<prop key="hibernate.hbm2ddl.auto">update</prop>
</props>
</property>
</bean>
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>
<bean id="fascadeController" class="sms.spring.fascade.FascadeControllerImpl"></bean>
<bean id="studentDao" class="sms.spring.dao.StudentDaoImpl"></bean>
<bean id="loginDao" class="sms.spring.dao.LoginDaoImpl"></bean>
<bean id="facultyDao" class="sms.spring.dao.FacultyDaoImpl"></bean>
<bean id="markDao" class="sms.spring.dao.MarkDaoImpl"></bean>
<bean id="notificationDao" class="sms.spring.dao.NotificationDaoImpl"></bean>
<tx:annotation-driven />
答案 0 :(得分:1)
问题不明确,但看起来您的控制器也应该使用@Controller
进行注释。属于Spring项目的所有具有自动连接依赖项的类都需要由Spring创建。简而言之,你永远不应该使用new
创建一个ApplicationContext#getBean()
的Spring类,或者当它被另一个类注入时创建它们。
此外,请记住构造函数,因为在创建bean时,自动连接的依赖项为null(未初始化),您需要创建一个用init()
注释的@PostConstruct
方法。 / p>
答案 1 :(得分:1)
两个主要原因是:
您必须告诉spring,在哪里扫描您的组件(确保包装正确)
您没有实际bean的实现(确保StudentDao也有@Service)
答案 2 :(得分:1)
请发布你得到的错误,同样从你发布的代码我可以看到,即使你用@service注释注释了StudentDaoImpl类,你再次在xml配置中定义相同,请使用其中一个注释基于配置或基于xml的配置。
请检查您的文件是否有
<context:annotation-config/>
(如果启用了组件扫描,则不需要)