我的DAO中有以下代码：
@Repository
public class PedidoDAO {
private static final Logger logger = Logger.getLogger(PedidoDAO.class);
@PersistenceContext
private EntityManager manager;
public List<Pedido> getPedidos() throws SQLException {
List<Pedido> listPedidos = new ArrayList<Pedido>();
try {
listPedidos = manager.createQuery("select e from Pedido e", Pedido.class).getResultList();
} catch (NoResultException e) {
logger.error("Data does'nt exist!");
} catch (Exception e) {
logger.error("Error creating HQL to get Pedidos: ", e);
}
return listPedidos;
}
}
直到这里一切正常，如果我在控制器中调用这个DAO（已经有@Transactional），它可以正常工作。
但是当我在这里创建一个@Service时：
@Transactional
@Service
public class PedidoBU {
@Autowired
private PedidoDAO pedidoDAO;
public List<Pedido> getPedidos() throws SQLException{
return pedidoDAO.getPedidos();
}
}
它没有连接DAO和pedidoDAO.getPedidos（）会抛出NullPointerException。
我在服务中做错了什么？我理解错误的EntityManager和Transactional控制器吗？
servlet中的我的EntityManager配置：
<context:component-scan base-package="com.nassoft.erpweb"/>
<bean id="myDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
<property name="driverClass" value="com.mysql.jdbc.Driver" />
<property name="jdbcUrl" value="jdbc:mysql://127.0.0.1:3306/my_database" />
<property name="user" value="" />
<property name="password" value="" />
<property name="minPoolSize" value="5" />
<property name="maxPoolSize" value="20" />
<property name="maxStatements" value="50" />
<property name="idleConnectionTestPeriod" value="3000" />
<property name="loginTimeout" value="300" />
</bean>
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="dataSource" ref="myDataSource" />
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter" />
</property>
</bean>
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager" autowire-candidate="default">
<property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>
<tx:annotation-driven/>
编辑。
我的控制器调用@Service：
@Controller
public class PedidoVendaController {
@Autowired
private PedidoBU pedidoBU;
public String listPedidoVenda(){
listPedidos = pedidoBU.getPedidos();
}
}
第一个问题解决了自动装配pedidoBU。
但是当我启动服务器时出现了另一个错误：
2015-02-24 13:20:14 WARN XmlWebApplicationContext:489 - Exception encountered during context initialization - cancelling refresh attempt
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'pedidoVendaController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.nassoft.erpweb.register.business.PedidoBU com.nassoft.erpweb.register.controller.PedidoVendaController.pedidoBU; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.nassoft.erpweb.register.business.PedidoBU] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:301)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1186)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:298)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:706)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:762)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482)
at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:658)
at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:624)
at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:672)
at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:543)
at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:484)
at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136)
at javax.servlet.GenericServlet.init(GenericServlet.java:160)
at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1280)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1193)
at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1088)
at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5123)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5407)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.nassoft.erpweb.register.business.PedidoBU com.nassoft.erpweb.register.controller.PedidoVendaController.pedidoBU; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.nassoft.erpweb.register.business.PedidoBU] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:522)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:298)
... 29 more
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.nassoft.erpweb.register.business.PedidoBU] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1118)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:967)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:862)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:494)
第二个问题解决了：我试图在我的代码的另一个点使用另一个@Service内的@Service而不使用接口。当我改为使用一个接口时，它将主类称为代理并且工作正常。