Question

我正在努力解决一个似乎很愚蠢但我无法理解的问题。我正在使用SpringSource提供的localhost服务器测试一个非常简单的servlet。这是servlet中有意义的部分：

@ContextConfiguration("configuration.xml")
public class Refresh extends HttpServlet {
private static final long serialVersionUID = 1L;

@Autowired
private IUserDao uDao;

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    User a = uDao.getUser(1);
}

}

我确信Dao是正确的，因为从junit测试类调用它一切正常。奇怪的是，我应该找到类似“FailedToLoadApplicationContext”异常的东西，但错误只是一个NullPointerException，例如@Autowired和@ContextConfiguration不存在。这应该是我正在使用的服务器的问题吗？

这是我的configuration.xml文件：

<?xml version="1.0" encoding="UTF-8"?>
<!-- Spring configuration for data access tier -->
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:jee="http://www.springframework.org/schema/jee"
xmlns:mvc="http://www.springframework.org/schema/mvc"
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/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
    http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.0.xsd
    http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
    http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd">

<context:component-scan base-package="com.firststepteam.dao">
    <context:include-filter type="annotation"
        expression="org.springframework.stereotype.Repository"/>
</context:component-scan>

<context:component-scan base-package="com.firststepteam.services">
    <context:include-filter type="annotation"
        expression="org.springframework.stereotype.Service"/>
</context:component-scan>

<!-- View resolver -> JSP -->
<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
    <property name="prefix" value="/WEB-INF/jsp/"/>
    <property name="suffix" value=".jsp"/>
</bean>

<!-- PropertyPlaceholderConfigurer, serve a recuperare le impostazioni
per il dataSource nel file firststep.conf -->
<bean id="placeHolder" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="locations" value="classpath:hostingData.conf" />
</bean>

<!-- DataSource, sorgente del db, i value sono in firststep.conf -->
<bean id="dataSource"
    class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="${jdbc.db.driverClassName}" />
    <property name="url" value="${jdbc.db.url}" />
    <property name="username" value="${jdbc.db.username}" />
    <property name="password" value="${jdbc.db.password}" />
</bean>

<!-- JPA E HIBERNATE -->
<bean id="jpaVendorAdapter" class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
  <property name="database" value="MYSQL" />
  <property name="generateDdl" value="true" />
</bean>

<!-- ENTITY MANAGER FACTORY -->
<bean id="dbEntityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
  <property name="dataSource" ref="dataSource" />
  <property name="persistenceUnitName" value="fs_db" />
  <property name="jpaVendorAdapter" ref="jpaVendorAdapter" />
</bean>

<tx:annotation-driven />
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
    <property name="entityManagerFactory" ref="dbEntityManagerFactory" />
</bean>

<bean class = "org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor" />

</beans>

如您所见，我正在使用JPA和Hibernate

Answer 1

您应该为：

添加一个setter

private IUserDao uDao;

为什么Spring tc localhost服务器抛出nullPointerException而不是autowiring？

1 个答案: