Spring 3新手 - NoSuchBeanDefinitionException - 我錯過了什麼？

Question

剛開始看春3和MVC。我得到以下異常...

org.springframework.beans.factory.BeanCreationException：創建名爲'registerController'的bean時出錯：注入自動裝配依賴項失敗;嵌套異常是org.springframework.beans.factory.BeanCreationException：無法自動裝入字段：private browniePoints.dao.UserDao browniePoints.web.RegisterController.userDao;嵌套異常是org.springframework.beans.factory.NoSuchBeanDefinitionException：找不到匹配依賴類型爲[browniePoints.dao.UserDao]的bean類型：期望至少有1個bean符合此依賴關係的自動連線候選。依賴註釋：{@ org.springframework.beans.factory.annotation.Autowired（required = true）}

從所有的例子我有谷歌這是所有需要的。我錯過了什麼？

接口...

package browniePoints.dao; 

public interface UserDao 
{ 

實現...

package browniePoints.dao.impl; 

@Component 
public class UserDaoImpl implements UserDao 
{ 
@Autowired 
private DataSource dataSource; 

控制器...

package browniePoints.web; 

@Controller 
public class RegisterController 
{ 
@Autowired 
private UserDao userDao; 

web.xml中有一個servlet，它指向以下xml配置...

<?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:mvc="http://www.springframework.org/schema/mvc" 
xmlns:context="http://www.springframework.org/schema/context" 
xsi:schemaLocation=" 
    http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd 
    http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd 
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd"> 

    <!-- Scans the classpath of this application for @Components to deploy as beans --> 
    <context:component-scan base-package="browniePoints.web" /> 

    <!-- Configures the @Controller programming model --> 
    <mvc:annotation-driven /> 

    <!-- Forwards requests to the "/" resource to the "index" view --> 
    <mvc:view-controller path="/" view-name="index"/> 

    <!-- Handles HTTP GET requests for /resources/** by efficiently serving up static resources in the ${webappRoot}/resources/ directory --> 
    <mvc:resources mapping="/resources/**" location="/resources/" /> 

    <!-- point URLs ending .jsp to views in /WEB-INF/views --> 
    <bean id="viewResolver"  class="org.springframework.web.servlet.view.InternalResourceViewResolver"> 
     <property name="viewClass" value="org.springframework.web.servlet.view.JstlView">  </property> 
     <property name="prefix" value="/WEB-INF/views/"></property> 
     <property name="suffix" value=".jsp"></property>   
    </bean> 

    <!-- load properties from config.properites --> 
    <bean id="placeholderConfig" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">  
     <property name="location" value="config.properties" /> 
    </bean> 

    <!-- Define a SQL Server datasource --> 
    <bean id="dataSource" destroy-method="close"  class="org.springframework.jdbc.datasource.DriverManagerDataSource"> 
     <property name="driverClassName" value="${jdbc.driverClassName}"/> 
     <property name="url" value="${jdbc.url}"/> 
     <property name="username" value="${jdbc.username}"/> 
     <property name="password" value="${jdbc.password}"/> 
    </bean> 

    </beans> 

謝謝。

Answer 1

在黑暗中射擊;你缺少的UserDaoImpl包在你的組件掃描指令：

<context:component-scan base-package="x.z"/>