原始碼：

@Service
public class UserService implements UserServices{

    @Autowired
    UserMapper userMapper ;

    public  boolean AddUserInfo(User user)
    {
        if(userMapper.insert(user)>0)
            return  true;
        else
            return  false;
    }

}

目錄結構：

報錯資訊：

No qualifying bean of
 
 type [com.mybatistest.dao.UserMapper] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency.

即userMapper注入失敗，原因是配置檔案中沒有啟動springmvc註解功能（介面不需要寫註解@services）

解決方法：在spring-servlet.xml中新增以下程式碼（其中11至37行為配置json轉換器）

<!-- 避免IE執行AJAX時,返回JSON出現下載檔案 -->
 

    <bean id="mappingJacksonHttpMessageConverter"
          class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
        <property name="supportedMediaTypes">
            <list>
                <value>text/html;charset=UTF-8</value>
            </list
 
>
        </property>
    </bean>

    <mvc:annotation-driven>
        <mvc:message-converters register-defaults="true">
            <bean
                    class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter"
                    p:supportedMediaTypes="*/*" />
        </mvc:message-converters>
    </mvc:annotation-driven>

    <bean
            class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
        <property name="messageConverters">
            <list>
                <ref bean="mappingJacksonHttpMessageConverter" />
            </list>
        </property>
    </bean>

    <mvc:default-servlet-handler />
    <!-- 啟動Spring MVC的註解功能，完成請求和註解POJO的對映 -->
    <bean
            class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
        <property name="messageConverters">
            <list>
                <ref bean="mappingJacksonHttpMessageConverter" /><!-- json轉換器 -->
            </list>
        </property>
    </bean>

注：注入失敗更常見的原因是在spring-servlet.xml中沒有新增掃描目錄，導致專案啟動時沒掃描相應的包，無法建立例項。解決辦法是在spring-servlet.xml中新增要掃描的包，比如：

 <context:component-scan base-package="com.mybatistest.Controller"/>
    <context:component-scan base-package="com.mybatistest.service.implement"/>
    <context:component-scan base-package="com.mybatistest.dao"/>